SmogRank / Episodes / United States

North-eastern United States and Canada, July 2026

For 8 days, from 14 to 21 July 2026, 264 cities in the United States and Canada had PM2.5 at least twice their usual for the time of year. The worst reading was Superior, Wisconsin, United States: 548.0 µg/m³ on 16 July, about 54× its usual 10.1.

No cause namedWe have no fire or smoke records for these days, so we only say what the measurements show.
Cities reached264in 2 countries
Days814 to 21 July 2026
Worst day18 July185 cities counted
Furthest above usual54×Superior

Day by day

18 July 185 cities at twice their usual or more
Ann ArborWhite OakSkokieBlue IslandEvergreen ParkNilesPark RidgeWheatonLexington-FayetteSaint MatthewsJeffersonvilleJeffersontownNew AlbanyLouisvilleNicholasvilleValley StationElizabethtownOwensboroEvansvilleKingsportBristolKnoxvilleCookevilleRouyn-NorandaMaryvilleHendersonvilleClarksvilleAshevilleNashvilleHickoryPaducahClemmonsGreensboroLexingtonColumbiaChattanoogaArnoldSpartanburgGreenvilleCharlotteOttawaDurhamUticaMorrisvilleRaleighJacksonDyersburgClaytonCamdenCornwallFayettevilleColumbiaGreenvilleNewarkBartlettAnkenyDes MoinesWest MemphisMontréalFort DodgeRivière-des-Prairies–Pointe-aux-TremblesBrossardBurlingtonSaint-Jean-sur-RichelieuSorel-TracySpringfieldLibertyRaymoreKansas CityShawiniganKansas CitySaint JosephDrummondvilleLeawoodTrois-RivièresOlatheSherbrookeLawrenceLaconiaBellevueOmahaSpringdaleLa VistaTopekaL'Ancienne-LoretteSioux FallsQuébecFort SmithLincolnBrookingsSaint-GeorgesLewistonWatertownSaguenayAugustaTulsaJenksMcAlesterDerbyWichitaPonca CityGrand IslandAberdeenBangorEdmondOklahoma CityMooreEdmundstonNepeanWinston-SalemWake ForestCincinnatiGranbyJasperMankatoNorwoodCharlestonSt. LouisMasonPortsmouthFort ThomasAshlandEast Saint LouisLebanonColumbusPortlandRutlandMiddletownUniversity CityLemayPortsmouthGranite CityFishersMuncieMuscatineAlbanyIndianapolisLexingtonLafayetteKokomoTerre HautePittsfieldFall RiverBloomingtonProvidenceKeeneAndersonDerryBostonPawtucketSalemQuincyUpper AltonSpringfieldLynnGatineauRochesterBrocktonHaverhillCoventryNewburghWorcesterGreenfieldHartfordHarrisonburgRoanoke RapidsLowellFraminghamNew LondonSpringfieldNorth ChicopeeWaterlooMilfordJersey CityDecaturNew HavenRoanokePeoriaChampaignElizabethBridgeportToms RiverBloomingtonChesapeakeWinnipegPatersonWaterburyIowa CityCedar RapidsSouth VinelandDanburyClintonWhite PlainsNorth BayLindenDavenportKingstonMolineNew York CityNew CityScrantonTrentonNew BrunswickFort LeeHolbrookEwingEast HamptonSewellPleasantvilleAllentownDaytonAtlantic CityWest FargoRandolphSyracuseWashingtonBensalemScaggsvilleRochesterRichmondCharlottesvilleHopewellJolietPennsaukenAbingtonBarrieSt. CatharinesOxon Hill-GlassmanorShort PumpReadingWest MifflinBuffaloSpringfieldBayonnePhiladelphiaPainesvillePeterboroughYoungstownWarrenGreater SudburyMichigan CityAltoonaTorontoEdgewoodBellevilleSaint PaulAuroraShakopeeBaltimoreDoverAllistonMinneapolisLimaNewarkBearSaint MichaelElktonElkhartMcKeesportLebanonSouth LaurelRockvilleWilkinsburgHarrisburgGaryChesterOconomowocNorristownNewmarketEau ClaireWyomingSouth BendRockfordCalumet CityPittsburghNapervilleColumbusApple ValleyLancasterWilmingtonFort WayneOakvilleSaint CloudRose HillMississaugaDublinKalamazooHunt ValleyHermitageClevelandPortageState CollegeWestervilleEvanstonBethlehemBurnsvilleCantonHammondGahannaBramptonSpringfieldJohnstownMiltonHamiltonWaterdownAkronBridgeviewUpper Saint ClairCarlisleWeirton HeightsDoltonOak LawnHollandCleveland HeightsGuelphRedfordEast ChicagoBrantfordMadisonMiddletonRoyal OakKitchenerAshburnFranklin ParkChambersburgShaker HeightsBlaineSteubenvilleBrookfieldYorkWeirtonElginChicagoBrookfieldElmwood ParkErieHagerstownMedinaCaryGreen BayDes PlainesDearbornAppletonMilwaukeeJenisonBay CityLondonDetroitLansingSouth MilwaukeeFlintGrand RapidsWaukeshaTaylorSt. ThomasPerrysburgWindsorPort HuronLincoln ParkYpsilantiToledoNorthbrookChathamSouthfieldOregonSarniaZionSault Ste. MarieEastpointeMarquetteDuluthSuperior
11 Jul12131415161718192021222324
Every measured city in the area, coloured by its PM2.5 that day; a dark ring marks a city at twice its usual or more. Bars: cities counted each day, coloured by their median level. Choose a day or press play; without JavaScript, the days link to that day's world ranking.

How it spread

Royal OakRoyal Oak, 11 July: 17.5 µg/m³, 1.3× usualRoyal Oak, 12 July: 26.7 µg/m³, 2.0× usualRoyal Oak, 13 July: 27.0 µg/m³, 2.0× usualRoyal Oak, 14 July: 24.1 µg/m³, 1.8× usualRoyal Oak, 15 July: 75.4 µg/m³, 5.6× usualRoyal Oak, 16 July: 289.0 µg/m³, 22× usualRoyal Oak, 17 July: 225.5 µg/m³, 17× usualRoyal Oak, 18 July: 45.0 µg/m³, 3.4× usualRoyal Oak, 19 July: 49.4 µg/m³, 3.7× usualRoyal Oak, 20 July: 40.6 µg/m³, 3.0× usualRoyal Oak, 21 July: 33.3 µg/m³, 2.5× usualRoyal Oak, 22 July: 2.1 µg/m³, 0.2× usualRoyal Oak, 23 July: 1.7 µg/m³, 0.1× usualRoyal Oak, 24 July: 4.1 µg/m³, 0.3× usualSault Ste. MarieSault Ste. Marie, 11 July: 11.9 µg/m³, 1.4× usualSault Ste. Marie, 12 July: 13.3 µg/m³, 1.6× usualSault Ste. Marie, 13 July: 10.3 µg/m³, 1.2× usualSault Ste. Marie, 14 July: 27.3 µg/m³, 3.2× usualSault Ste. Marie, 15 July: 185.0 µg/m³, 22× usualSault Ste. Marie, 16 July: 309.0 µg/m³, 36× usualSault Ste. Marie, 17 July: 66.6 µg/m³, 7.8× usualSault Ste. Marie, 18 July: 72.2 µg/m³, 8.5× usualSault Ste. Marie, 19 July: 12.1 µg/m³, 1.4× usualSault Ste. Marie, 20 July: 30.6 µg/m³, 3.6× usualSault Ste. Marie, 21 July: 8.3 µg/m³, 1.0× usualSault Ste. Marie, 22 July: 4.1 µg/m³, 0.5× usualSault Ste. Marie, 23 July: 6.0 µg/m³, 0.7× usualSault Ste. Marie, 24 July: 5.7 µg/m³, 0.7× usualSuperiorSuperior, 11 July: 12.4 µg/m³, 1.2× usualSuperior, 12 July: 8.8 µg/m³, 0.9× usualSuperior, 13 July: 8.3 µg/m³, 0.8× usualSuperior, 14 July: 10.2 µg/m³, 1.0× usualSuperior, 15 July: 339.0 µg/m³, 34× usualSuperior, 16 July: 548.0 µg/m³, 54× usualSuperior, 17 July: 246.0 µg/m³, 24× usualSuperior, 18 July: 42.1 µg/m³, 4.2× usualSuperior, 19 July: 38.0 µg/m³, 3.8× usualSuperior, 20 July: 28.4 µg/m³, 2.8× usualSuperior, 21 July: 6.2 µg/m³, 0.6× usualSuperior, 22 July: 3.6 µg/m³, 0.4× usualSuperior, 23 July: 9.9 µg/m³, 1.0× usualSuperior, 24 July: 10.8 µg/m³, 1.1× usualDuluthDuluth, 11 July: 10.3 µg/m³, 1.0× usualDuluth, 12 July: 7.0 µg/m³, 0.7× usualDuluth, 13 July: 7.2 µg/m³, 0.7× usualDuluth, 14 July: 9.3 µg/m³, 0.9× usualDuluth, 15 July: 277.0 µg/m³, 28× usualDuluth, 16 July: 466.0 µg/m³, 47× usualDuluth, 17 July: 216.0 µg/m³, 22× usualDuluth, 18 July: 37.0 µg/m³, 3.7× usualDuluth, 19 July: 32.0 µg/m³, 3.2× usualDuluth, 20 July: 24.9 µg/m³, 2.5× usualDuluth, 21 July: 5.0 µg/m³, 0.5× usualDuluth, 22 July: 3.2 µg/m³, 0.3× usualDuluth, 23 July: 9.0 µg/m³, 0.9× usualDuluth, 24 July: 9.5 µg/m³, 1.0× usualMarquetteMarquette, 11 July: 12.6 µg/m³, 1.5× usualMarquette, 12 July: 9.4 µg/m³, 1.1× usualMarquette, 13 July: 8.3 µg/m³, 1.0× usualMarquette, 14 July: 10.9 µg/m³, 1.3× usualMarquette, 15 July: 322.0 µg/m³, 37× usualMarquette, 16 July: 398.0 µg/m³, 46× usualMarquette, 17 July: 167.0 µg/m³, 19× usualMarquette, 18 July: 174.0 µg/m³, 20× usualMarquette, 19 July: 139.0 µg/m³, 16× usualMarquette, 20 July: 77.1 µg/m³, 9.0× usualMarquette, 21 July: 5.5 µg/m³, 0.6× usualMarquette, 22 July: 3.7 µg/m³, 0.4× usualMarquette, 23 July: 13.2 µg/m³, 1.5× usualMarquette, 24 July: 9.9 µg/m³, 1.2× usualWindsorWindsor, 11 July: 9.9 µg/m³, 0.9× usualWindsor, 12 July: 16.8 µg/m³, 1.6× usualWindsor, 13 July: 18.9 µg/m³, 1.8× usualWindsor, 14 July: 14.7 µg/m³, 1.4× usualWindsor, 15 July: 81.8 µg/m³, 7.6× usualWindsor, 16 July: 341.0 µg/m³, 32× usualWindsor, 17 July: 210.0 µg/m³, 20× usualWindsor, 18 July: 28.4 µg/m³, 2.7× usualWindsor, 19 July: 44.0 µg/m³, 4.1× usualWindsor, 20 July: 30.8 µg/m³, 2.9× usualWindsor, 21 July: 26.1 µg/m³, 2.4× usualWindsor, 22 July: 3.6 µg/m³, 0.3× usualWindsor, 23 July: 5.8 µg/m³, 0.5× usualWindsor, 24 July: 6.2 µg/m³, 0.6× usualSarniaSarnia, 11 July: 11.5 µg/m³, 1.3× usualSarnia, 12 July: 16.1 µg/m³, 1.8× usualSarnia, 13 July: 16.3 µg/m³, 1.8× usualSarnia, 14 July: 12.3 µg/m³, 1.4× usualSarnia, 15 July: 106.0 µg/m³, 12× usualSarnia, 16 July: 323.0 µg/m³, 36× usualSarnia, 17 July: 196.0 µg/m³, 22× usualSarnia, 18 July: 50.4 µg/m³, 5.6× usualSarnia, 19 July: 34.0 µg/m³, 3.8× usualSarnia, 20 July: 27.8 µg/m³, 3.1× usualSarnia, 21 July: 21.7 µg/m³, 2.4× usualSarnia, 22 July: 3.3 µg/m³, 0.4× usualSarnia, 23 July: 5.7 µg/m³, 0.6× usualSarnia, 24 July: 7.7 µg/m³, 0.9× usualDetroitDetroit, 11 July: 9.3 µg/m³, 0.9× usualDetroit, 12 July: 15.9 µg/m³, 1.5× usualDetroit, 13 July: 19.1 µg/m³, 1.8× usualDetroit, 14 July: 13.4 µg/m³, 1.3× usualDetroit, 15 July: 69.4 µg/m³, 6.6× usualDetroit, 16 July: 315.0 µg/m³, 30× usualDetroit, 17 July: 199.0 µg/m³, 19× usualDetroit, 18 July: 27.3 µg/m³, 2.6× usualDetroit, 19 July: 41.6 µg/m³, 4.0× usualDetroit, 20 July: 30.7 µg/m³, 2.9× usualDetroit, 21 July: 24.8 µg/m³, 2.4× usualDetroit, 22 July: 3.6 µg/m³, 0.3× usualDetroit, 23 July: 5.5 µg/m³, 0.5× usualDetroit, 24 July: 7.6 µg/m³, 0.7× usualLincoln ParkLincoln Park, 11 July: 9.6 µg/m³, 1.0× usualLincoln Park, 12 July: 16.4 µg/m³, 1.7× usualLincoln Park, 13 July: 17.9 µg/m³, 1.8× usualLincoln Park, 14 July: 12.7 µg/m³, 1.3× usualLincoln Park, 15 July: 60.0 µg/m³, 6.1× usualLincoln Park, 16 July: 314.0 µg/m³, 32× usualLincoln Park, 17 July: 203.0 µg/m³, 21× usualLincoln Park, 18 July: 25.9 µg/m³, 2.6× usualLincoln Park, 19 July: 40.7 µg/m³, 4.2× usualLincoln Park, 20 July: 28.9 µg/m³, 2.9× usualLincoln Park, 21 July: 23.3 µg/m³, 2.4× usualLincoln Park, 22 July: 3.4 µg/m³, 0.3× usualLincoln Park, 23 July: 5.3 µg/m³, 0.5× usualLincoln Park, 24 July: 6.6 µg/m³, 0.7× usualDearbornDearborn, 11 July: 9.1 µg/m³, 0.8× usualDearborn, 12 July: 15.2 µg/m³, 1.4× usualDearborn, 13 July: 17.9 µg/m³, 1.6× usualDearborn, 14 July: 12.4 µg/m³, 1.1× usualDearborn, 15 July: 60.6 µg/m³, 5.5× usualDearborn, 16 July: 305.0 µg/m³, 27× usualDearborn, 17 July: 206.0 µg/m³, 19× usualDearborn, 18 July: 27.2 µg/m³, 2.5× usualDearborn, 19 July: 40.1 µg/m³, 3.6× usualDearborn, 20 July: 28.9 µg/m³, 2.6× usualDearborn, 21 July: 24.2 µg/m³, 2.2× usualDearborn, 22 July: 3.7 µg/m³, 0.3× usualDearborn, 23 July: 9.3 µg/m³, 0.8× usualDearborn, 24 July: 7.7 µg/m³, 0.7× usualPort HuronPort Huron, 11 July: 11.1 µg/m³, 1.2× usualPort Huron, 12 July: 14.7 µg/m³, 1.6× usualPort Huron, 13 July: 15.2 µg/m³, 1.6× usualPort Huron, 14 July: 11.7 µg/m³, 1.2× usualPort Huron, 15 July: 131.0 µg/m³, 14× usualPort Huron, 16 July: 301.0 µg/m³, 32× usualPort Huron, 17 July: 189.0 µg/m³, 20× usualPort Huron, 18 July: 49.7 µg/m³, 5.3× usualPort Huron, 19 July: 33.7 µg/m³, 3.6× usualPort Huron, 20 July: 26.5 µg/m³, 2.8× usualPort Huron, 21 July: 21.2 µg/m³, 2.3× usualPort Huron, 22 July: 3.1 µg/m³, 0.3× usualPort Huron, 23 July: 5.8 µg/m³, 0.6× usualPort Huron, 24 July: 6.2 µg/m³, 0.7× usualSouthfieldSouthfield, 11 July: 10.0 µg/m³, 1.1× usualSouthfield, 12 July: 15.4 µg/m³, 1.8× usualSouthfield, 13 July: 15.1 µg/m³, 1.7× usualSouthfield, 14 July: 12.6 µg/m³, 1.4× usualSouthfield, 15 July: 56.5 µg/m³, 6.5× usualSouthfield, 16 July: 297.0 µg/m³, 34× usualSouthfield, 17 July: 212.0 µg/m³, 24× usualSouthfield, 18 July: 33.7 µg/m³, 3.9× usualSouthfield, 19 July: 39.0 µg/m³, 4.5× usualSouthfield, 20 July: 28.7 µg/m³, 3.3× usualSouthfield, 21 July: 23.8 µg/m³, 2.7× usualSouthfield, 22 July: 3.1 µg/m³, 0.4× usualSouthfield, 23 July: 5.1 µg/m³, 0.6× usualSouthfield, 24 July: 6.8 µg/m³, 0.8× usualTaylorTaylor, 11 July: 8.8 µg/m³, 0.9× usualTaylor, 12 July: 14.9 µg/m³, 1.6× usualTaylor, 13 July: 15.7 µg/m³, 1.6× usualTaylor, 14 July: 11.8 µg/m³, 1.2× usualTaylor, 15 July: 52.3 µg/m³, 5.4× usualTaylor, 16 July: 296.0 µg/m³, 31× usualTaylor, 17 July: 197.0 µg/m³, 21× usualTaylor, 18 July: 23.7 µg/m³, 2.5× usualTaylor, 19 July: 38.8 µg/m³, 4.0× usualTaylor, 20 July: 28.8 µg/m³, 3.0× usualTaylor, 21 July: 23.2 µg/m³, 2.4× usualTaylor, 22 July: 3.3 µg/m³, 0.3× usualTaylor, 23 July: 5.3 µg/m³, 0.6× usualTaylor, 24 July: 6.9 µg/m³, 0.7× usualMilwaukeeMilwaukee, 11 July: 12.5 µg/m³, 1.2× usualMilwaukee, 12 July: 14.2 µg/m³, 1.4× usualMilwaukee, 13 July: 12.4 µg/m³, 1.2× usualMilwaukee, 14 July: 10.4 µg/m³, 1.0× usualMilwaukee, 15 July: 42.3 µg/m³, 4.2× usualMilwaukee, 16 July: 280.0 µg/m³, 28× usualMilwaukee, 17 July: no readingMilwaukee, 18 July: no readingMilwaukee, 19 July: no readingMilwaukee, 20 July: no readingMilwaukee, 21 July: no readingMilwaukee, 22 July: no readingMilwaukee, 23 July: no readingMilwaukee, 24 July: no readingWaukeshaWaukesha, 11 July: 12.1 µg/m³, 1.4× usualWaukesha, 12 July: 13.6 µg/m³, 1.5× usualWaukesha, 13 July: 12.5 µg/m³, 1.4× usualWaukesha, 14 July: 9.6 µg/m³, 1.1× usualWaukesha, 15 July: 33.7 µg/m³, 3.8× usualWaukesha, 16 July: 274.0 µg/m³, 31× usualWaukesha, 17 July: 136.0 µg/m³, 15× usualWaukesha, 18 July: 44.7 µg/m³, 5.0× usualWaukesha, 19 July: 92.0 µg/m³, 10× usualWaukesha, 20 July: 42.0 µg/m³, 4.7× usualWaukesha, 21 July: 7.6 µg/m³, 0.9× usualWaukesha, 22 July: 4.2 µg/m³, 0.5× usualWaukesha, 23 July: 5.7 µg/m³, 0.6× usualWaukesha, 24 July: 7.3 µg/m³, 0.8× usualEastpointeEastpointe, 11 July: 7.8 µg/m³, 1.1× usualEastpointe, 12 July: 13.2 µg/m³, 1.8× usualEastpointe, 13 July: 15.2 µg/m³, 2.1× usualEastpointe, 14 July: 9.5 µg/m³, 1.3× usualEastpointe, 15 July: 64.9 µg/m³, 8.9× usualEastpointe, 16 July: 273.0 µg/m³, 37× usualEastpointe, 17 July: 183.0 µg/m³, 25× usualEastpointe, 18 July: 27.2 µg/m³, 3.7× usualEastpointe, 19 July: 37.7 µg/m³, 5.2× usualEastpointe, 20 July: 26.2 µg/m³, 3.6× usualEastpointe, 21 July: 20.2 µg/m³, 2.8× usualEastpointe, 22 July: 3.0 µg/m³, 0.4× usualEastpointe, 23 July: 4.6 µg/m³, 0.6× usualEastpointe, 24 July: 5.5 µg/m³, 0.8× usualBrookfieldBrookfield, 11 July: 16.2 µg/m³, 1.5× usualBrookfield, 12 July: 20.6 µg/m³, 1.9× usualBrookfield, 13 July: 16.9 µg/m³, 1.5× usualBrookfield, 14 July: 10.5 µg/m³, 1.0× usualBrookfield, 15 July: 40.9 µg/m³, 3.7× usualBrookfield, 16 July: 270.5 µg/m³, 25× usualBrookfield, 17 July: 132.0 µg/m³, 12× usualBrookfield, 18 July: 54.5 µg/m³, 5.0× usualBrookfield, 19 July: 97.5 µg/m³, 8.9× usualBrookfield, 20 July: 51.5 µg/m³, 4.7× usualBrookfield, 21 July: 5.4 µg/m³, 0.5× usualBrookfield, 22 July: 0.5 µg/m³, 0.0× usualBrookfield, 23 July: 1.1 µg/m³, 0.1× usualBrookfield, 24 July: 6.1 µg/m³, 0.6× usualLondonLondon, 11 July: 11.8 µg/m³, 1.3× usualLondon, 12 July: 15.2 µg/m³, 1.7× usualLondon, 13 July: 16.9 µg/m³, 1.9× usualLondon, 14 July: 12.2 µg/m³, 1.4× usualLondon, 15 July: 80.6 µg/m³, 9.0× usualLondon, 16 July: 267.0 µg/m³, 30× usualLondon, 17 July: 210.0 µg/m³, 23× usualLondon, 18 July: 43.0 µg/m³, 4.8× usualLondon, 19 July: 28.2 µg/m³, 3.1× usualLondon, 20 July: 28.1 µg/m³, 3.1× usualLondon, 21 July: 21.1 µg/m³, 2.3× usualLondon, 22 July: 2.9 µg/m³, 0.3× usualLondon, 23 July: 4.7 µg/m³, 0.5× usualLondon, 24 July: 6.7 µg/m³, 0.7× usualBay CityBay City, 11 July: 9.5 µg/m³, 1.0× usualBay City, 12 July: 14.2 µg/m³, 1.6× usualBay City, 13 July: 12.5 µg/m³, 1.4× usualBay City, 14 July: 9.4 µg/m³, 1.0× usualBay City, 15 July: 86.1 µg/m³, 9.5× usualBay City, 16 July: 266.0 µg/m³, 29× usualBay City, 17 July: 212.0 µg/m³, 23× usualBay City, 18 July: 34.3 µg/m³, 3.8× usualBay City, 19 July: 37.4 µg/m³, 4.1× usualBay City, 20 July: 29.0 µg/m³, 3.2× usualBay City, 21 July: 17.5 µg/m³, 1.9× usualBay City, 22 July: 4.3 µg/m³, 0.5× usualBay City, 23 July: 4.9 µg/m³, 0.5× usualBay City, 24 July: 6.5 µg/m³, 0.7× usualSt. ThomasSt. Thomas, 11 July: 12.9 µg/m³, 1.6× usualSt. Thomas, 12 July: 17.9 µg/m³, 2.2× usualSt. Thomas, 13 July: 17.8 µg/m³, 2.1× usualSt. Thomas, 14 July: 14.1 µg/m³, 1.7× usualSt. Thomas, 15 July: 71.1 µg/m³, 8.6× usualSt. Thomas, 16 July: 259.0 µg/m³, 31× usualSt. Thomas, 17 July: 247.0 µg/m³, 30× usualSt. Thomas, 18 July: 44.4 µg/m³, 5.3× usualSt. Thomas, 19 July: 31.0 µg/m³, 3.7× usualSt. Thomas, 20 July: 27.8 µg/m³, 3.3× usualSt. Thomas, 21 July: 19.3 µg/m³, 2.3× usualSt. Thomas, 22 July: 2.8 µg/m³, 0.3× usualSt. Thomas, 23 July: 4.2 µg/m³, 0.5× usualSt. Thomas, 24 July: 4.9 µg/m³, 0.6× usualGreen BayGreen Bay, 11 July: 15.7 µg/m³, 1.7× usualGreen Bay, 12 July: 14.7 µg/m³, 1.6× usualGreen Bay, 13 July: 12.2 µg/m³, 1.3× usualGreen Bay, 14 July: 10.5 µg/m³, 1.1× usualGreen Bay, 15 July: 75.8 µg/m³, 8.1× usualGreen Bay, 16 July: 255.0 µg/m³, 27× usualGreen Bay, 17 July: 157.0 µg/m³, 17× usualGreen Bay, 18 July: 83.3 µg/m³, 8.9× usualGreen Bay, 19 July: 128.0 µg/m³, 14× usualGreen Bay, 20 July: 36.4 µg/m³, 3.9× usualGreen Bay, 21 July: 8.1 µg/m³, 0.9× usualGreen Bay, 22 July: 4.5 µg/m³, 0.5× usualGreen Bay, 23 July: 5.4 µg/m³, 0.6× usualGreen Bay, 24 July: 6.6 µg/m³, 0.7× usualFlintFlint, 11 July: 10.7 µg/m³, 1.3× usualFlint, 12 July: 13.2 µg/m³, 1.6× usualFlint, 13 July: 12.9 µg/m³, 1.6× usualFlint, 14 July: 10.6 µg/m³, 1.3× usualFlint, 15 July: 84.7 µg/m³, 10× usualFlint, 16 July: 251.0 µg/m³, 31× usualFlint, 17 July: 161.0 µg/m³, 20× usualFlint, 18 July: 35.3 µg/m³, 4.3× usualFlint, 19 July: 34.6 µg/m³, 4.2× usualFlint, 20 July: 27.0 µg/m³, 3.3× usualFlint, 21 July: 17.1 µg/m³, 2.1× usualFlint, 22 July: 6.6 µg/m³, 0.8× usualFlint, 23 July: 7.7 µg/m³, 0.9× usualFlint, 24 July: 9.6 µg/m³, 1.2× usualSouth MilwaukeeSouth Milwaukee, 11 July: 11.6 µg/m³, 1.4× usualSouth Milwaukee, 12 July: 11.8 µg/m³, 1.5× usualSouth Milwaukee, 13 July: 11.6 µg/m³, 1.4× usualSouth Milwaukee, 14 July: 9.2 µg/m³, 1.1× usualSouth Milwaukee, 15 July: 36.7 µg/m³, 4.5× usualSouth Milwaukee, 16 July: 248.0 µg/m³, 31× usualSouth Milwaukee, 17 July: 128.0 µg/m³, 16× usualSouth Milwaukee, 18 July: 45.4 µg/m³, 5.6× usualSouth Milwaukee, 19 July: 62.2 µg/m³, 7.7× usualSouth Milwaukee, 20 July: 43.0 µg/m³, 5.3× usualSouth Milwaukee, 21 July: 7.1 µg/m³, 0.9× usualSouth Milwaukee, 22 July: 4.4 µg/m³, 0.5× usualSouth Milwaukee, 23 July: 6.2 µg/m³, 0.8× usualSouth Milwaukee, 24 July: 7.5 µg/m³, 0.9× usualChathamChatham, 11 July: 9.2 µg/m³, 1.3× usualChatham, 12 July: 14.5 µg/m³, 2.0× usualChatham, 13 July: 15.8 µg/m³, 2.2× usualChatham, 14 July: 12.0 µg/m³, 1.6× usualChatham, 15 July: 49.1 µg/m³, 6.7× usualChatham, 16 July: 245.0 µg/m³, 34× usualChatham, 17 July: 166.0 µg/m³, 23× usualChatham, 18 July: 25.2 µg/m³, 3.5× usualChatham, 19 July: 35.4 µg/m³, 4.8× usualChatham, 20 July: 28.3 µg/m³, 3.9× usualChatham, 21 July: 20.1 µg/m³, 2.8× usualChatham, 22 July: 3.2 µg/m³, 0.4× usualChatham, 23 July: 4.3 µg/m³, 0.6× usualChatham, 24 July: 5.8 µg/m³, 0.8× usualOconomowocOconomowoc, 11 July: 18.0 µg/m³, 1.2× usualOconomowoc, 12 July: 19.6 µg/m³, 1.3× usualOconomowoc, 13 July: 18.1 µg/m³, 1.2× usualOconomowoc, 14 July: 13.7 µg/m³, 0.9× usualOconomowoc, 15 July: 34.8 µg/m³, 2.4× usualOconomowoc, 16 July: 243.0 µg/m³, 17× usualOconomowoc, 17 July: 121.0 µg/m³, 8.3× usualOconomowoc, 18 July: 47.5 µg/m³, 3.3× usualOconomowoc, 19 July: 99.5 µg/m³, 6.8× usualOconomowoc, 20 July: 44.6 µg/m³, 3.1× usualOconomowoc, 21 July: 10.1 µg/m³, 0.7× usualOconomowoc, 22 July: 3.2 µg/m³, 0.2× usualOconomowoc, 23 July: 5.6 µg/m³, 0.4× usualOconomowoc, 24 July: 7.3 µg/m³, 0.5× usualAppletonAppleton, 11 July: 13.7 µg/m³, 1.6× usualAppleton, 12 July: 13.9 µg/m³, 1.6× usualAppleton, 13 July: 9.9 µg/m³, 1.2× usualAppleton, 14 July: 8.9 µg/m³, 1.0× usualAppleton, 15 July: 88.7 µg/m³, 10× usualAppleton, 16 July: 235.0 µg/m³, 28× usualAppleton, 17 July: 146.0 µg/m³, 17× usualAppleton, 18 July: 70.3 µg/m³, 8.3× usualAppleton, 19 July: 135.0 µg/m³, 16× usualAppleton, 20 July: 38.1 µg/m³, 4.5× usualAppleton, 21 July: 11.2 µg/m³, 1.3× usualAppleton, 22 July: 5.2 µg/m³, 0.6× usualAppleton, 23 July: 5.4 µg/m³, 0.6× usualAppleton, 24 July: 6.1 µg/m³, 0.7× usualRedfordRedford, 11 July: 5.5 µg/m³, 0.5× usualRedford, 12 July: 9.5 µg/m³, 0.9× usualRedford, 13 July: 11.1 µg/m³, 1.1× usualRedford, 14 July: 8.6 µg/m³, 0.8× usualRedford, 15 July: 40.7 µg/m³, 3.9× usualRedford, 16 July: 224.0 µg/m³, 21× usualRedford, 17 July: 160.0 µg/m³, 15× usualRedford, 18 July: 23.3 µg/m³, 2.2× usualRedford, 19 July: 29.6 µg/m³, 2.8× usualRedford, 20 July: 25.9 µg/m³, 2.5× usualRedford, 21 July: 19.4 µg/m³, 1.8× usualRedford, 22 July: 2.1 µg/m³, 0.2× usualRedford, 23 July: 4.8 µg/m³, 0.5× usualRedford, 24 July: 8.1 µg/m³, 0.8× usualKitchenerKitchener, 11 July: 13.8 µg/m³, 1.5× usualKitchener, 12 July: 17.0 µg/m³, 1.8× usualKitchener, 13 July: 17.6 µg/m³, 1.9× usualKitchener, 14 July: 12.0 µg/m³, 1.3× usualKitchener, 15 July: 115.0 µg/m³, 13× usualKitchener, 16 July: 200.0 µg/m³, 22× usualKitchener, 17 July: 168.0 µg/m³, 18× usualKitchener, 18 July: 56.7 µg/m³, 6.2× usualKitchener, 19 July: 14.9 µg/m³, 1.6× usualKitchener, 20 July: 18.9 µg/m³, 2.1× usualKitchener, 21 July: 19.6 µg/m³, 2.1× usualKitchener, 22 July: 2.4 µg/m³, 0.3× usualKitchener, 23 July: no readingKitchener, 24 July: 5.8 µg/m³, 0.6× usualBrantfordBrantford, 11 July: 13.0 µg/m³, 1.4× usualBrantford, 12 July: 16.7 µg/m³, 1.9× usualBrantford, 13 July: 16.6 µg/m³, 1.8× usualBrantford, 14 July: 12.8 µg/m³, 1.4× usualBrantford, 15 July: 130.0 µg/m³, 14× usualBrantford, 16 July: 193.0 µg/m³, 21× usualBrantford, 17 July: 178.0 µg/m³, 20× usualBrantford, 18 July: 56.8 µg/m³, 6.3× usualBrantford, 19 July: 15.1 µg/m³, 1.7× usualBrantford, 20 July: 21.3 µg/m³, 2.4× usualBrantford, 21 July: 17.2 µg/m³, 1.9× usualBrantford, 22 July: 3.4 µg/m³, 0.4× usualBrantford, 23 July: 4.7 µg/m³, 0.5× usualBrantford, 24 July: 6.3 µg/m³, 0.7× usualOregonOregon, 11 July: 8.4 µg/m³, 0.8× usualOregon, 12 July: 16.6 µg/m³, 1.5× usualOregon, 13 July: 19.2 µg/m³, 1.7× usualOregon, 14 July: 17.7 µg/m³, 1.6× usualOregon, 15 July: 16.6 µg/m³, 1.5× usualOregon, 16 July: 377.0 µg/m³, 34× usualOregon, 17 July: 207.0 µg/m³, 19× usualOregon, 18 July: 19.3 µg/m³, 1.8× usualOregon, 19 July: 41.8 µg/m³, 3.8× usualOregon, 20 July: 39.4 µg/m³, 3.6× usualOregon, 21 July: 24.2 µg/m³, 2.2× usualOregon, 22 July: 4.1 µg/m³, 0.4× usualOregon, 23 July: 5.9 µg/m³, 0.5× usualOregon, 24 July: 7.6 µg/m³, 0.7× usualPerrysburgPerrysburg, 11 July: 10.6 µg/m³, 0.9× usualPerrysburg, 12 July: 18.9 µg/m³, 1.7× usualPerrysburg, 13 July: 20.4 µg/m³, 1.8× usualPerrysburg, 14 July: 18.3 µg/m³, 1.6× usualPerrysburg, 15 July: 17.3 µg/m³, 1.5× usualPerrysburg, 16 July: 355.0 µg/m³, 32× usualPerrysburg, 17 July: 254.0 µg/m³, 23× usualPerrysburg, 18 July: 24.4 µg/m³, 2.2× usualPerrysburg, 19 July: 46.3 µg/m³, 4.1× usualPerrysburg, 20 July: 50.7 µg/m³, 4.5× usualPerrysburg, 21 July: 33.0 µg/m³, 2.9× usualPerrysburg, 22 July: 5.7 µg/m³, 0.5× usualPerrysburg, 23 July: 9.3 µg/m³, 0.8× usualPerrysburg, 24 July: 12.3 µg/m³, 1.1× usualToledoToledo, 11 July: 10.1 µg/m³, 1.0× usualToledo, 12 July: 17.9 µg/m³, 1.8× usualToledo, 13 July: 20.4 µg/m³, 2.0× usualToledo, 14 July: 15.5 µg/m³, 1.6× usualToledo, 15 July: 11.6 µg/m³, 1.2× usualToledo, 16 July: 334.0 µg/m³, 33× usualToledo, 17 July: 212.0 µg/m³, 21× usualToledo, 18 July: 17.3 µg/m³, 1.7× usualToledo, 19 July: 43.5 µg/m³, 4.4× usualToledo, 20 July: 40.3 µg/m³, 4.0× usualToledo, 21 July: 21.8 µg/m³, 2.2× usualToledo, 22 July: 4.3 µg/m³, 0.4× usualToledo, 23 July: 6.9 µg/m³, 0.7× usualToledo, 24 July: 8.1 µg/m³, 0.8× usualNorthbrookNorthbrook, 11 July: 9.5 µg/m³, 1.0× usualNorthbrook, 12 July: 13.3 µg/m³, 1.4× usualNorthbrook, 13 July: 15.8 µg/m³, 1.6× usualNorthbrook, 14 July: 14.3 µg/m³, 1.5× usualNorthbrook, 15 July: 16.2 µg/m³, 1.7× usualNorthbrook, 16 July: 322.0 µg/m³, 34× usualNorthbrook, 17 July: 157.0 µg/m³, 16× usualNorthbrook, 18 July: 39.1 µg/m³, 4.1× usualNorthbrook, 19 July: 54.2 µg/m³, 5.6× usualNorthbrook, 20 July: 48.9 µg/m³, 5.1× usualNorthbrook, 21 July: 9.9 µg/m³, 1.0× usualNorthbrook, 22 July: 3.2 µg/m³, 0.3× usualNorthbrook, 23 July: 5.5 µg/m³, 0.6× usualNorthbrook, 24 July: 7.6 µg/m³, 0.8× usualGrand RapidsGrand Rapids, 11 July: 8.5 µg/m³, 0.8× usualGrand Rapids, 12 July: 13.8 µg/m³, 1.4× usualGrand Rapids, 13 July: 12.5 µg/m³, 1.2× usualGrand Rapids, 14 July: 11.6 µg/m³, 1.1× usualGrand Rapids, 15 July: 20.0 µg/m³, 2.0× usualGrand Rapids, 16 July: 313.0 µg/m³, 31× usualGrand Rapids, 17 July: 220.0 µg/m³, 22× usualGrand Rapids, 18 July: 39.2 µg/m³, 3.8× usualGrand Rapids, 19 July: 52.0 µg/m³, 5.1× usualGrand Rapids, 20 July: 54.8 µg/m³, 5.4× usualGrand Rapids, 21 July: 16.1 µg/m³, 1.6× usualGrand Rapids, 22 July: 3.8 µg/m³, 0.4× usualGrand Rapids, 23 July: 6.0 µg/m³, 0.6× usualGrand Rapids, 24 July: 7.2 µg/m³, 0.7× usualYpsilantiYpsilanti, 11 July: 9.0 µg/m³, 1.0× usualYpsilanti, 12 July: 15.8 µg/m³, 1.8× usualYpsilanti, 13 July: 13.4 µg/m³, 1.5× usualYpsilanti, 14 July: 11.9 µg/m³, 1.4× usualYpsilanti, 15 July: 15.6 µg/m³, 1.8× usualYpsilanti, 16 July: 286.0 µg/m³, 33× usualYpsilanti, 17 July: 216.0 µg/m³, 25× usualYpsilanti, 18 July: 27.6 µg/m³, 3.1× usualYpsilanti, 19 July: 37.8 µg/m³, 4.3× usualYpsilanti, 20 July: 32.2 µg/m³, 3.7× usualYpsilanti, 21 July: 23.5 µg/m³, 2.7× usualYpsilanti, 22 July: 4.1 µg/m³, 0.5× usualYpsilanti, 23 July: 4.8 µg/m³, 0.5× usualYpsilanti, 24 July: 6.4 µg/m³, 0.7× usualLansingLansing, 11 July: no readingLansing, 12 July: no readingLansing, 13 July: 14.1 µg/m³, 1.5× usualLansing, 14 July: 8.5 µg/m³, 0.9× usualLansing, 15 July: 21.5 µg/m³, 2.3× usualLansing, 16 July: 278.0 µg/m³, 30× usualLansing, 17 July: 223.0 µg/m³, 24× usualLansing, 18 July: 29.5 µg/m³, 3.2× usualLansing, 19 July: 36.0 µg/m³, 3.9× usualLansing, 20 July: 32.0 µg/m³, 3.5× usualLansing, 21 July: 20.1 µg/m³, 2.2× usualLansing, 22 July: 3.7 µg/m³, 0.4× usualLansing, 23 July: 5.2 µg/m³, 0.6× usualLansing, 24 July: 7.3 µg/m³, 0.8× usualJenisonJenison, 11 July: 8.6 µg/m³, 0.9× usualJenison, 12 July: 13.9 µg/m³, 1.4× usualJenison, 13 July: 13.0 µg/m³, 1.4× usualJenison, 14 July: 12.6 µg/m³, 1.3× usualJenison, 15 July: 18.4 µg/m³, 1.9× usualJenison, 16 July: 275.0 µg/m³, 29× usualJenison, 17 July: 212.0 µg/m³, 22× usualJenison, 18 July: 38.9 µg/m³, 4.1× usualJenison, 19 July: 55.6 µg/m³, 5.8× usualJenison, 20 July: 54.1 µg/m³, 5.6× usualJenison, 21 July: 15.7 µg/m³, 1.6× usualJenison, 22 July: 3.5 µg/m³, 0.4× usualJenison, 23 July: 5.4 µg/m³, 0.6× usualJenison, 24 July: 6.6 µg/m³, 0.7× usualElginElgin, 11 July: 15.5 µg/m³, 1.4× usualElgin, 12 July: 21.0 µg/m³, 1.9× usualElgin, 13 July: 22.0 µg/m³, 1.9× usualElgin, 14 July: 19.3 µg/m³, 1.7× usualElgin, 15 July: 17.2 µg/m³, 1.5× usualElgin, 16 July: 275.0 µg/m³, 24× usualElgin, 17 July: 142.0 µg/m³, 13× usualElgin, 18 July: 37.1 µg/m³, 3.3× usualElgin, 19 July: 77.3 µg/m³, 6.8× usualElgin, 20 July: 59.7 µg/m³, 5.3× usualElgin, 21 July: 13.1 µg/m³, 1.2× usualElgin, 22 July: 5.1 µg/m³, 0.5× usualElgin, 23 July: 10.1 µg/m³, 0.9× usualElgin, 24 July: 11.7 µg/m³, 1.0× usualZionZion, 11 July: 9.0 µg/m³, 1.2× usualZion, 12 July: 11.8 µg/m³, 1.6× usualZion, 13 July: 12.6 µg/m³, 1.7× usualZion, 14 July: 11.0 µg/m³, 1.4× usualZion, 15 July: 24.5 µg/m³, 3.2× usualZion, 16 July: 274.0 µg/m³, 36× usualZion, 17 July: 127.0 µg/m³, 17× usualZion, 18 July: 36.8 µg/m³, 4.8× usualZion, 19 July: 49.4 µg/m³, 6.5× usualZion, 20 July: 43.5 µg/m³, 5.7× usualZion, 21 July: 7.2 µg/m³, 0.9× usualZion, 22 July: 3.3 µg/m³, 0.4× usualZion, 23 July: 4.7 µg/m³, 0.6× usualZion, 24 July: 6.7 µg/m³, 0.9× usualElmwood ParkElmwood Park, 11 July: 8.6 µg/m³, 0.8× usualElmwood Park, 12 July: 13.2 µg/m³, 1.2× usualElmwood Park, 13 July: 19.0 µg/m³, 1.8× usualElmwood Park, 14 July: 16.2 µg/m³, 1.5× usualElmwood Park, 15 July: 13.9 µg/m³, 1.3× usualElmwood Park, 16 July: 267.0 µg/m³, 25× usualElmwood Park, 17 July: 128.0 µg/m³, 12× usualElmwood Park, 18 July: 33.9 µg/m³, 3.1× usualElmwood Park, 19 July: 52.3 µg/m³, 4.8× usualElmwood Park, 20 July: 47.2 µg/m³, 4.4× usualElmwood Park, 21 July: 10.9 µg/m³, 1.0× usualElmwood Park, 22 July: 4.3 µg/m³, 0.4× usualElmwood Park, 23 July: 7.2 µg/m³, 0.7× usualElmwood Park, 24 July: 9.5 µg/m³, 0.9× usualDes PlainesDes Plaines, 11 July: 8.6 µg/m³, 0.9× usualDes Plaines, 12 July: 11.1 µg/m³, 1.2× usualDes Plaines, 13 July: 13.0 µg/m³, 1.4× usualDes Plaines, 14 July: 12.0 µg/m³, 1.3× usualDes Plaines, 15 July: 11.8 µg/m³, 1.3× usualDes Plaines, 16 July: 256.0 µg/m³, 27× usualDes Plaines, 17 July: 119.0 µg/m³, 13× usualDes Plaines, 18 July: 31.0 µg/m³, 3.3× usualDes Plaines, 19 July: 47.9 µg/m³, 5.1× usualDes Plaines, 20 July: 42.3 µg/m³, 4.5× usualDes Plaines, 21 July: 8.6 µg/m³, 0.9× usualDes Plaines, 22 July: 3.0 µg/m³, 0.3× usualDes Plaines, 23 July: 5.7 µg/m³, 0.6× usualDes Plaines, 24 July: 7.7 µg/m³, 0.8× usualCaryCary, 11 July: 9.6 µg/m³, 1.0× usualCary, 12 July: 12.4 µg/m³, 1.3× usualCary, 13 July: 12.6 µg/m³, 1.4× usualCary, 14 July: 11.8 µg/m³, 1.3× usualCary, 15 July: 13.4 µg/m³, 1.4× usualCary, 16 July: 252.0 µg/m³, 27× usualCary, 17 July: 110.0 µg/m³, 12× usualCary, 18 July: 28.9 µg/m³, 3.1× usualCary, 19 July: 55.9 µg/m³, 6.0× usualCary, 20 July: 42.5 µg/m³, 4.6× usualCary, 21 July: 7.8 µg/m³, 0.8× usualCary, 22 July: 3.2 µg/m³, 0.3× usualCary, 23 July: 5.5 µg/m³, 0.6× usualCary, 24 July: 6.8 µg/m³, 0.7× usualFranklin ParkFranklin Park, 11 July: 9.6 µg/m³, 0.8× usualFranklin Park, 12 July: 13.5 µg/m³, 1.2× usualFranklin Park, 13 July: 17.6 µg/m³, 1.5× usualFranklin Park, 14 July: 15.9 µg/m³, 1.4× usualFranklin Park, 15 July: 14.0 µg/m³, 1.2× usualFranklin Park, 16 July: 249.0 µg/m³, 22× usualFranklin Park, 17 July: 132.0 µg/m³, 12× usualFranklin Park, 18 July: 33.9 µg/m³, 3.0× usualFranklin Park, 19 July: 53.9 µg/m³, 4.7× usualFranklin Park, 20 July: 49.3 µg/m³, 4.3× usualFranklin Park, 21 July: 11.4 µg/m³, 1.0× usualFranklin Park, 22 July: 3.8 µg/m³, 0.3× usualFranklin Park, 23 July: 8.7 µg/m³, 0.8× usualFranklin Park, 24 July: 10.7 µg/m³, 0.9× usualDoltonDolton, 11 July: 7.8 µg/m³, 0.7× usualDolton, 12 July: 13.3 µg/m³, 1.1× usualDolton, 13 July: 19.4 µg/m³, 1.7× usualDolton, 14 July: 17.8 µg/m³, 1.5× usualDolton, 15 July: 14.1 µg/m³, 1.2× usualDolton, 16 July: 239.0 µg/m³, 21× usualDolton, 17 July: 118.0 µg/m³, 10× usualDolton, 18 July: 31.1 µg/m³, 2.7× usualDolton, 19 July: 52.9 µg/m³, 4.6× usualDolton, 20 July: 46.3 µg/m³, 4.0× usualDolton, 21 July: 13.6 µg/m³, 1.2× usualDolton, 22 July: 3.2 µg/m³, 0.3× usualDolton, 23 July: 7.9 µg/m³, 0.7× usualDolton, 24 July: 8.3 µg/m³, 0.7× usualSteubenvilleSteubenville, 11 July: 8.2 µg/m³, 0.8× usualSteubenville, 12 July: 11.6 µg/m³, 1.1× usualSteubenville, 13 July: 11.0 µg/m³, 1.1× usualSteubenville, 14 July: 14.4 µg/m³, 1.4× usualSteubenville, 15 July: 14.9 µg/m³, 1.4× usualSteubenville, 16 July: 106.0 µg/m³, 10× usualSteubenville, 17 July: 236.0 µg/m³, 23× usualSteubenville, 18 July: 70.8 µg/m³, 6.9× usualSteubenville, 19 July: 41.5 µg/m³, 4.0× usualSteubenville, 20 July: 31.6 µg/m³, 3.1× usualSteubenville, 21 July: 22.1 µg/m³, 2.1× usualSteubenville, 22 July: 7.3 µg/m³, 0.7× usualSteubenville, 23 July: 7.3 µg/m³, 0.7× usualSteubenville, 24 July: 6.6 µg/m³, 0.6× usualChicagoChicago, 11 July: 8.7 µg/m³, 0.9× usualChicago, 12 July: 13.1 µg/m³, 1.4× usualChicago, 13 July: 18.9 µg/m³, 2.0× usualChicago, 14 July: 14.6 µg/m³, 1.5× usualChicago, 15 July: 11.9 µg/m³, 1.2× usualChicago, 16 July: 233.0 µg/m³, 24× usualChicago, 17 July: 111.0 µg/m³, 12× usualChicago, 18 July: 29.9 µg/m³, 3.1× usualChicago, 19 July: 51.3 µg/m³, 5.3× usualChicago, 20 July: 43.4 µg/m³, 4.5× usualChicago, 21 July: 10.6 µg/m³, 1.1× usualChicago, 22 July: 3.9 µg/m³, 0.4× usualChicago, 23 July: 7.0 µg/m³, 0.7× usualChicago, 24 July: 9.2 µg/m³, 1.0× usualBridgeviewBridgeview, 11 July: 9.7 µg/m³, 0.8× usualBridgeview, 12 July: 14.6 µg/m³, 1.2× usualBridgeview, 13 July: 20.0 µg/m³, 1.7× usualBridgeview, 14 July: 17.1 µg/m³, 1.5× usualBridgeview, 15 July: 14.4 µg/m³, 1.2× usualBridgeview, 16 July: 229.0 µg/m³, 20× usualBridgeview, 17 July: 122.0 µg/m³, 10× usualBridgeview, 18 July: 31.9 µg/m³, 2.7× usualBridgeview, 19 July: 54.3 µg/m³, 4.6× usualBridgeview, 20 July: 46.1 µg/m³, 3.9× usualBridgeview, 21 July: 12.1 µg/m³, 1.0× usualBridgeview, 22 July: 4.1 µg/m³, 0.4× usualBridgeview, 23 July: 9.4 µg/m³, 0.8× usualBridgeview, 24 July: 9.0 µg/m³, 0.8× usualMedinaMedina, 11 July: 9.6 µg/m³, 1.1× usualMedina, 12 July: 18.0 µg/m³, 2.1× usualMedina, 13 July: 16.7 µg/m³, 2.0× usualMedina, 14 July: 14.4 µg/m³, 1.7× usualMedina, 15 July: 13.0 µg/m³, 1.5× usualMedina, 16 July: 191.0 µg/m³, 22× usualMedina, 17 July: 229.0 µg/m³, 27× usualMedina, 18 July: 20.4 µg/m³, 2.4× usualMedina, 19 July: 47.8 µg/m³, 5.6× usualMedina, 20 July: 38.4 µg/m³, 4.5× usualMedina, 21 July: 25.3 µg/m³, 3.0× usualMedina, 22 July: 3.4 µg/m³, 0.4× usualMedina, 23 July: 5.1 µg/m³, 0.6× usualMedina, 24 July: 6.9 µg/m³, 0.8× usualBrookfieldBrookfield, 11 July: 7.8 µg/m³, 0.8× usualBrookfield, 12 July: 12.5 µg/m³, 1.3× usualBrookfield, 13 July: 15.9 µg/m³, 1.7× usualBrookfield, 14 July: 12.9 µg/m³, 1.4× usualBrookfield, 15 July: 10.0 µg/m³, 1.1× usualBrookfield, 16 July: 223.0 µg/m³, 24× usualBrookfield, 17 July: 116.0 µg/m³, 12× usualBrookfield, 18 July: 29.4 µg/m³, 3.1× usualBrookfield, 19 July: 52.6 µg/m³, 5.6× usualBrookfield, 20 July: 47.5 µg/m³, 5.1× usualBrookfield, 21 July: 10.3 µg/m³, 1.1× usualBrookfield, 22 July: 3.5 µg/m³, 0.4× usualBrookfield, 23 July: 7.8 µg/m³, 0.8× usualBrookfield, 24 July: 11.4 µg/m³, 1.2× usualEvanstonEvanston, 11 July: 8.8 µg/m³, 0.7× usualEvanston, 12 July: 13.2 µg/m³, 1.1× usualEvanston, 13 July: 18.2 µg/m³, 1.5× usualEvanston, 14 July: 15.0 µg/m³, 1.3× usualEvanston, 15 July: 11.0 µg/m³, 0.9× usualEvanston, 16 July: 216.0 µg/m³, 18× usualEvanston, 17 July: 145.5 µg/m³, 12× usualEvanston, 18 July: 22.6 µg/m³, 1.9× usualEvanston, 19 July: 54.3 µg/m³, 4.6× usualEvanston, 20 July: 48.5 µg/m³, 4.1× usualEvanston, 21 July: 18.0 µg/m³, 1.5× usualEvanston, 22 July: 0.2 µg/m³, 0.0× usualEvanston, 23 July: 2.0 µg/m³, 0.2× usualEvanston, 24 July: 8.9 µg/m³, 0.7× usualHollandHolland, 11 July: 4.4 µg/m³, 0.4× usualHolland, 12 July: 7.7 µg/m³, 0.8× usualHolland, 13 July: 7.8 µg/m³, 0.8× usualHolland, 14 July: 8.2 µg/m³, 0.8× usualHolland, 15 July: 12.4 µg/m³, 1.2× usualHolland, 16 July: 213.0 µg/m³, 21× usualHolland, 17 July: 157.0 µg/m³, 16× usualHolland, 18 July: 30.1 µg/m³, 3.0× usualHolland, 19 July: 46.1 µg/m³, 4.6× usualHolland, 20 July: 41.4 µg/m³, 4.1× usualHolland, 21 July: 9.9 µg/m³, 1.0× usualHolland, 22 July: 0.4 µg/m³, 0.0× usualHolland, 23 July: 1.6 µg/m³, 0.2× usualHolland, 24 July: 3.3 µg/m³, 0.3× usualWyomingWyoming, 11 July: 11.6 µg/m³, 0.9× usualWyoming, 12 July: 15.4 µg/m³, 1.2× usualWyoming, 13 July: 17.0 µg/m³, 1.4× usualWyoming, 14 July: 16.1 µg/m³, 1.3× usualWyoming, 15 July: 19.8 µg/m³, 1.6× usualWyoming, 16 July: 210.0 µg/m³, 17× usualWyoming, 17 July: 168.0 µg/m³, 13× usualWyoming, 18 July: 35.6 µg/m³, 2.8× usualWyoming, 19 July: 46.0 µg/m³, 3.7× usualWyoming, 20 July: 47.0 µg/m³, 3.8× usualWyoming, 21 July: 18.7 µg/m³, 1.5× usualWyoming, 22 July: 6.9 µg/m³, 0.6× usualWyoming, 23 July: 11.6 µg/m³, 0.9× usualWyoming, 24 July: 11.8 µg/m³, 0.9× usualClevelandCleveland, 11 July: 9.6 µg/m³, 0.8× usualCleveland, 12 July: 15.2 µg/m³, 1.3× usualCleveland, 13 July: 15.5 µg/m³, 1.4× usualCleveland, 14 July: 15.7 µg/m³, 1.4× usualCleveland, 15 July: 14.6 µg/m³, 1.3× usualCleveland, 16 July: 204.0 µg/m³, 18× usualCleveland, 17 July: 175.5 µg/m³, 16× usualCleveland, 18 July: 37.8 µg/m³, 3.3× usualCleveland, 19 July: 36.8 µg/m³, 3.3× usualCleveland, 20 July: 36.0 µg/m³, 3.2× usualCleveland, 21 July: 22.6 µg/m³, 2.0× usualCleveland, 22 July: 3.7 µg/m³, 0.3× usualCleveland, 23 July: 7.3 µg/m³, 0.6× usualCleveland, 24 July: 10.5 µg/m³, 0.9× usualCantonCanton, 11 July: 8.6 µg/m³, 0.8× usualCanton, 12 July: 14.6 µg/m³, 1.4× usualCanton, 13 July: 15.2 µg/m³, 1.4× usualCanton, 14 July: 17.5 µg/m³, 1.6× usualCanton, 15 July: 14.1 µg/m³, 1.3× usualCanton, 16 July: 156.0 µg/m³, 14× usualCanton, 17 July: 203.5 µg/m³, 19× usualCanton, 18 July: 29.9 µg/m³, 2.8× usualCanton, 19 July: 38.9 µg/m³, 3.6× usualCanton, 20 July: 29.9 µg/m³, 2.8× usualCanton, 21 July: 19.7 µg/m³, 1.8× usualCanton, 22 July: 4.6 µg/m³, 0.4× usualCanton, 23 July: 12.8 µg/m³, 1.2× usualCanton, 24 July: 8.3 µg/m³, 0.8× usualKalamazooKalamazoo, 11 July: 8.4 µg/m³, 0.7× usualKalamazoo, 12 July: 13.5 µg/m³, 1.2× usualKalamazoo, 13 July: 15.3 µg/m³, 1.4× usualKalamazoo, 14 July: 14.2 µg/m³, 1.3× usualKalamazoo, 15 July: 12.0 µg/m³, 1.1× usualKalamazoo, 16 July: 203.0 µg/m³, 18× usualKalamazoo, 17 July: 189.0 µg/m³, 17× usualKalamazoo, 18 July: 29.3 µg/m³, 2.6× usualKalamazoo, 19 July: 43.9 µg/m³, 3.9× usualKalamazoo, 20 July: 45.9 µg/m³, 4.1× usualKalamazoo, 21 July: 20.8 µg/m³, 1.8× usualKalamazoo, 22 July: 4.0 µg/m³, 0.4× usualKalamazoo, 23 July: 7.6 µg/m³, 0.7× usualKalamazoo, 24 July: 7.2 µg/m³, 0.6× usualOak LawnOak Lawn, 11 July: 10.9 µg/m³, 1.1× usualOak Lawn, 12 July: 16.8 µg/m³, 1.8× usualOak Lawn, 13 July: 20.3 µg/m³, 2.1× usualOak Lawn, 14 July: 16.6 µg/m³, 1.7× usualOak Lawn, 15 July: 16.0 µg/m³, 1.7× usualOak Lawn, 16 July: 202.0 µg/m³, 21× usualOak Lawn, 17 July: 136.0 µg/m³, 14× usualOak Lawn, 18 July: 34.5 µg/m³, 3.6× usualOak Lawn, 19 July: 66.4 µg/m³, 6.9× usualOak Lawn, 20 July: 52.5 µg/m³, 5.5× usualOak Lawn, 21 July: 13.6 µg/m³, 1.4× usualOak Lawn, 22 July: 3.8 µg/m³, 0.4× usualOak Lawn, 23 July: 9.5 µg/m³, 1.0× usualOak Lawn, 24 July: 11.1 µg/m³, 1.2× usualWestervilleWesterville, 11 July: 7.0 µg/m³, 0.6× usualWesterville, 12 July: 15.6 µg/m³, 1.4× usualWesterville, 13 July: 14.9 µg/m³, 1.3× usualWesterville, 14 July: 14.5 µg/m³, 1.3× usualWesterville, 15 July: 14.2 µg/m³, 1.3× usualWesterville, 16 July: 46.3 µg/m³, 4.2× usualWesterville, 17 July: 202.0 µg/m³, 18× usualWesterville, 18 July: 9.1 µg/m³, 0.8× usualWesterville, 19 July: 41.6 µg/m³, 3.7× usualWesterville, 20 July: 36.8 µg/m³, 3.3× usualWesterville, 21 July: 19.6 µg/m³, 1.8× usualWesterville, 22 July: 4.6 µg/m³, 0.4× usualWesterville, 23 July: 5.3 µg/m³, 0.5× usualWesterville, 24 July: 7.7 µg/m³, 0.7× usualWeirtonWeirton, 11 July: 5.9 µg/m³, 0.7× usualWeirton, 12 July: 11.2 µg/m³, 1.4× usualWeirton, 13 July: 9.7 µg/m³, 1.2× usualWeirton, 14 July: 13.8 µg/m³, 1.7× usualWeirton, 15 July: 12.9 µg/m³, 1.6× usualWeirton, 16 July: 99.6 µg/m³, 12× usualWeirton, 17 July: 197.5 µg/m³, 24× usualWeirton, 18 July: 62.4 µg/m³, 7.6× usualWeirton, 19 July: 37.9 µg/m³, 4.6× usualWeirton, 20 July: 25.6 µg/m³, 3.1× usualWeirton, 21 July: 18.5 µg/m³, 2.3× usualWeirton, 22 July: 5.3 µg/m³, 0.6× usualWeirton, 23 July: 4.9 µg/m³, 0.6× usualWeirton, 24 July: 6.6 µg/m³, 0.8× usualEast ChicagoEast Chicago, 11 July: 7.6 µg/m³, 0.8× usualEast Chicago, 12 July: 11.2 µg/m³, 1.2× usualEast Chicago, 13 July: 13.6 µg/m³, 1.5× usualEast Chicago, 14 July: 13.0 µg/m³, 1.4× usualEast Chicago, 15 July: 11.7 µg/m³, 1.3× usualEast Chicago, 16 July: 193.0 µg/m³, 21× usualEast Chicago, 17 July: 110.0 µg/m³, 12× usualEast Chicago, 18 July: 27.7 µg/m³, 3.1× usualEast Chicago, 19 July: 47.7 µg/m³, 5.3× usualEast Chicago, 20 July: 41.9 µg/m³, 4.7× usualEast Chicago, 21 July: 14.1 µg/m³, 1.6× usualEast Chicago, 22 July: 4.0 µg/m³, 0.4× usualEast Chicago, 23 July: 8.3 µg/m³, 0.9× usualEast Chicago, 24 July: 7.4 µg/m³, 0.8× usualNapervilleNaperville, 11 July: 11.2 µg/m³, 1.0× usualNaperville, 12 July: 16.0 µg/m³, 1.5× usualNaperville, 13 July: 16.8 µg/m³, 1.5× usualNaperville, 14 July: 15.0 µg/m³, 1.4× usualNaperville, 15 July: 13.0 µg/m³, 1.2× usualNaperville, 16 July: 190.0 µg/m³, 17× usualNaperville, 17 July: 162.0 µg/m³, 15× usualNaperville, 18 July: 29.4 µg/m³, 2.7× usualNaperville, 19 July: 60.4 µg/m³, 5.5× usualNaperville, 20 July: 48.4 µg/m³, 4.4× usualNaperville, 21 July: 11.9 µg/m³, 1.1× usualNaperville, 22 July: 4.4 µg/m³, 0.4× usualNaperville, 23 July: 7.0 µg/m³, 0.6× usualNaperville, 24 July: 8.0 µg/m³, 0.7× usual11 Jul131517192123
The 60 cities with the highest readings of 264, in the order the episode reached them, 3 days before to 3 after. Each square is a day, coloured by that day's PM2.5; outlined: at twice the city's usual or more.
Good0–50
Moderate51–100
Sensitive groups101–150
Unhealthy151–200
Very unhealthy201–300
Hazardous301+

Every city it reached

CityDaysHighestUsualAbove usual
SuperiorWisconsin, United States5 548.016 July10.154×
DuluthMinnesota, United States4 466.016 July9.947×
MarquetteMichigan, United States6 398.016 July8.646×
EastpointeMichigan, United States6 273.016 July7.337×
Sault Ste. MarieOntario, Canada6 309.016 July8.536×
ZionIllinois, United States5 274.016 July7.636×
SarniaOntario, Canada6 323.016 July9.036×
OregonOhio, United States4 377.016 July11.034×
SouthfieldMichigan, United States6 297.016 July8.734×
ChathamOntario, Canada6 245.016 July7.334×
NorthbrookIllinois, United States5 322.016 July9.634×
ToledoOhio, United States4 334.016 July10.033×
YpsilantiMichigan, United States5 286.016 July8.833×
Lincoln ParkMichigan, United States6 314.016 July9.832×
Port HuronMichigan, United States6 301.016 July9.432×
WindsorOntario, Canada7 341.016 July10.732×
PerrysburgOhio, United States5 355.016 July11.232×
St. ThomasOntario, Canada6 259.016 July8.331×
TaylorMichigan, United States5 296.016 July9.631×
WaukeshaWisconsin, United States6 274.016 July8.931×
Grand RapidsMichigan, United States5 313.016 July10.231×
South MilwaukeeWisconsin, United States6 248.016 July8.131×
FlintMichigan, United States6 251.016 July8.231×
LansingMichigan, United States5 278.016 July9.230×
DetroitMichigan, United States6 315.016 July10.530×
LondonOntario, Canada6 267.016 July9.030×
Bay CityMichigan, United States6 266.016 July9.129×
JenisonMichigan, United States5 275.016 July9.629×
MilwaukeeWisconsin, United States2 280.016 July10.128×
AppletonWisconsin, United States6 235.016 July8.528×
DearbornMichigan, United States6 305.016 July11.127×
Des PlainesIllinois, United States5 256.016 July9.427×
Green BayWisconsin, United States6 255.016 July9.427×
CaryIllinois, United States5 252.016 July9.327×
MedinaOhio, United States5 229.017 July8.527×
HagerstownMaryland, United States3 149.017 July5.627×
EriePennsylvania, United States4 181.017 July7.325×
Elmwood ParkIllinois, United States5 267.016 July10.825×
BrookfieldWisconsin, United States6 270.516 July11.025×
ElginIllinois, United States5 275.016 July11.324×
ChicagoIllinois, United States5 233.016 July9.624×
WeirtonWest Virginia, United States5 197.517 July8.224×
YorkPennsylvania, United States3 185.017 July7.724×
BrookfieldIllinois, United States5 223.016 July9.424×
SteubenvilleOhio, United States5 236.017 July10.323×
BlaineMinnesota, United States3 186.016 July8.223×
Shaker HeightsOhio, United States5 185.516 July8.223×
ChambersburgPennsylvania, United States3 171.017 July7.822×
Franklin ParkIllinois, United States5 249.016 July11.422×
AshburnVirginia, United States2 172.017 July7.922×
KitchenerOntario, Canada4 200.016 July9.222×
MiddletonWisconsin, United States5 158.016 July7.322×
Royal OakMichigan, United States7 289.016 July13.422×
MadisonWisconsin, United States4 174.516 July8.122×
BrantfordOntario, Canada4 193.016 July9.021×
East ChicagoIndiana, United States5 193.016 July9.021×
RedfordMichigan, United States5 224.016 July10.521×
GuelphOntario, Canada4 181.016 July8.521×
HollandMichigan, United States5 213.016 July10.121×
Cleveland HeightsOhio, United States5 175.016 July8.321×
Oak LawnIllinois, United States5 202.016 July9.621×
Weirton HeightsWest Virginia, United States4 161.017 July7.821×
DoltonIllinois, United States5 239.016 July11.621×
CarlislePennsylvania, United States3 155.017 July7.720×
Upper Saint ClairPennsylvania, United States4 167.017 July8.420×
BridgeviewIllinois, United States5 229.016 July11.720×
AkronOhio, United States5 163.017 July8.419×
WaterdownOntario, Canada4 160.016 July8.319×
HamiltonOntario, Canada4 174.516 July9.119×
JohnstownPennsylvania, United States5 160.017 July8.419×
SpringfieldVirginia, United States2 160.017 July8.419×
MiltonOntario, Canada4 179.016 July9.419×
GahannaOhio, United States4 144.017 July7.619×
BramptonOntario, Canada4 153.016 July8.119×
CantonOhio, United States5 203.517 July10.819×
HammondIndiana, United States5 188.016 July10.019×
BurnsvilleMinnesota, United States3 172.016 July9.219×
BethlehemPennsylvania, United States3 128.016 July7.018×
State CollegePennsylvania, United States3 133.016 July7.318×
WestervilleOhio, United States4 202.017 July11.118×
EvanstonIllinois, United States4 216.016 July11.918×
HermitagePennsylvania, United States4 141.017 July7.818×
PortageIndiana, United States5 177.016 July9.818×
ClevelandOhio, United States5 204.016 July11.318×
Hunt ValleyMaryland, United States3 117.017 July6.518×
DublinOhio, United States4 162.017 July9.018×
KalamazooMichigan, United States5 203.016 July11.318×
MississaugaOntario, Canada4 138.016 July7.718×
Rose HillVirginia, United States2 145.017 July8.118×
OakvilleOntario, Canada4 157.016 July8.818×
Saint CloudMinnesota, United States2 146.015 July8.218×
Fort WayneIndiana, United States4 173.017 July9.917×
LancasterPennsylvania, United States3 146.017 July8.417×
WilmingtonDelaware, United States3 135.517 July7.817×
ColumbusOhio, United States4 183.517 July10.617×
PittsburghPennsylvania, United States5 176.517 July10.217×
Apple ValleyMinnesota, United States3 140.016 July8.117×
NapervilleIllinois, United States5 190.016 July11.017×
Calumet CityIllinois, United States5 175.016 July10.217×
RockfordIllinois, United States4 158.016 July9.317×
WyomingMichigan, United States5 210.016 July12.517×
South BendIndiana, United States5 161.017 July9.617×
NorristownPennsylvania, United States3 127.017 July7.617×
Eau ClaireWisconsin, United States5 142.016 July8.517×
NewmarketOntario, Canada4 147.016 July8.817×
OconomowocWisconsin, United States6 243.016 July14.617×
HarrisburgPennsylvania, United States3 153.017 July9.217×
South LaurelMaryland, United States2 123.017 July7.417×
RockvilleMaryland, United States2 113.017 July6.817×
GaryIndiana, United States4 161.016 July9.717×
WilkinsburgPennsylvania, United States4 161.017 July9.717×
ChesterPennsylvania, United States3 126.017 July7.617×
LebanonPennsylvania, United States3 142.017 July8.617×
McKeesportPennsylvania, United States4 155.017 July9.416×
ElkhartIndiana, United States4 162.017 July10.016×
ElktonMaryland, United States3 123.017 July7.716×
BearDelaware, United States3 126.017 July7.916×
Saint MichaelMinnesota, United States3 137.016 July8.616×
NewarkDelaware, United States3 130.517 July8.316×
LimaOhio, United States4 147.017 July9.416×
AllistonOntario, Canada4 118.016 July7.616×
BaltimoreMaryland, United States3 118.017 July7.616×
DoverDelaware, United States3 135.017 July8.716×
MinneapolisMinnesota, United States3 155.016 July10.016×
ShakopeeMinnesota, United States3 142.016 July9.215×
AuroraIllinois, United States4 148.017 July9.715×
Saint PaulMinnesota, United States3 154.016 July10.115×
BellevilleOntario, Canada3 112.016 July7.415×
EdgewoodMaryland, United States3 116.017 July7.715×
TorontoOntario, Canada4 136.016 July9.115×
AltoonaPennsylvania, United States3 127.017 July8.515×
Michigan CityIndiana, United States4 150.017 July10.115×
Greater SudburyOntario, Canada4 122.015 July8.315×
YoungstownOhio, United States4 138.017 July9.415×
WarrenOhio, United States5 160.017 July10.915×
PeterboroughOntario, Canada3 115.016 July7.915×
PainesvilleOhio, United States3 100.016 July6.914×
PhiladelphiaPennsylvania, United States4 144.017 July10.114×
BayonneNew Jersey, United States4 86.916 July6.114×
SpringfieldOhio, United States3 143.017 July10.114×
West MifflinPennsylvania, United States5 166.517 July11.814×
BuffaloNew York, United States4 131.016 July9.314×
ReadingPennsylvania, United States3 105.016 July7.614×
Short PumpVirginia, United States2 106.017 July7.714×
Oxon Hill-GlassmanorMaryland, United States2 106.017 July7.814×
St. CatharinesOntario, Canada4 107.017 July8.013×
BarrieOntario, Canada4 127.016 July9.613×
AbingtonPennsylvania, United States2 128.017 July10.013×
JolietIllinois, United States4 130.017 July10.213×
PennsaukenNew Jersey, United States4 120.517 July9.513×
HopewellVirginia, United States2 91.017 July7.412×
CharlottesvilleVirginia, United States2 101.017 July8.312×
RichmondVirginia, United States2 99.517 July8.212×
RochesterNew York, United States3 95.516 July8.012×
ScaggsvilleMaryland, United States2 114.017 July9.712×
WashingtonDistrict of Columbia, United States2 107.517 July9.411×
BensalemPennsylvania, United States3 104.017 July9.111×
SyracuseNew York, United States4 77.016 July7.011×
RandolphNew Jersey, United States4 82.416 July7.910×
West FargoNorth Dakota, United States2 112.016 July10.910×
Atlantic CityNew Jersey, United States3 84.717 July8.410×
DaytonOhio, United States3 100.017 July10.010×
AllentownPennsylvania, United States2 72.418 July7.39.9×
PleasantvilleNew Jersey, United States3 80.617 July8.89.2×
SewellNew Jersey, United States3 90.117 July9.99.1×
East HamptonVirginia, United States2 68.817 July7.69.1×
HolbrookNew York, United States4 65.816 July7.39.0×
EwingNew Jersey, United States4 83.616 July9.39.0×
TrentonNew Jersey, United States3 84.616 July9.58.9×
New BrunswickNew Jersey, United States3 75.616 July8.58.9×
Fort LeeNew Jersey, United States4 70.916 July8.08.9×
ScrantonPennsylvania, United States4 78.816 July9.08.8×
New York CityNew York, United States4 84.616 July9.78.7×
New CityNew York, United States4 51.216 July5.98.7×
MolineIllinois, United States2 75.019 July8.78.6×
KingstonOntario, Canada3 67.016 July7.98.5×
DavenportIowa, United States2 73.719 July8.78.5×
LindenNew Jersey, United States4 81.316 July9.88.3×
White PlainsNew York, United States4 51.716 July6.48.1×
North BayOntario, Canada4 63.016 July7.88.1×
ClintonIowa, United States2 75.819 July9.48.1×
DanburyConnecticut, United States4 67.316 July8.57.9×
South VinelandNew Jersey, United States3 62.317 July8.07.8×
Iowa CityIowa, United States2 67.719 July8.87.7×
Cedar RapidsIowa, United States2 65.319 July8.57.7×
WaterburyConnecticut, United States4 62.216 July8.37.5×
PatersonNew Jersey, United States4 66.616 July8.97.5×
WinnipegManitoba, Canada1 82.116 July11.17.4×
ChesapeakeVirginia, United States1 59.117 July8.07.4×
BloomingtonIllinois, United States2 63.119 July8.67.3×
Toms RiverNew Jersey, United States3 63.317 July8.87.2×
BridgeportConnecticut, United States4 65.616 July9.27.1×
PeoriaIllinois, United States2 73.319 July10.47.0×
ChampaignIllinois, United States2 63.919 July9.17.0×
ElizabethNew Jersey, United States4 74.316 July10.67.0×
RoanokeVirginia, United States2 54.817 July8.06.9×
DecaturIllinois, United States2 64.119 July9.46.8×
New HavenConnecticut, United States3 56.716 July8.46.8×
Jersey CityNew Jersey, United States4 64.816 July9.76.7×
MilfordMassachusetts, United States2 41.818 July6.36.6×
WaterlooIowa, United States1 52.419 July8.06.6×
North ChicopeeMassachusetts, United States3 40.718 July6.36.5×
SpringfieldMassachusetts, United States3 47.618 July7.66.3×
New LondonConnecticut, United States4 51.016 July8.26.2×
GatineauQuebec, Canada1 36.612 July5.96.2×
FraminghamMassachusetts, United States2 40.418 July6.66.1×
LowellMassachusetts, United States2 42.618 July7.06.1×
Roanoke RapidsNorth Carolina, United States1 58.017 July9.66.0×
HarrisonburgVirginia, United States3 43.417 July7.26.0×
WorcesterMassachusetts, United States2 41.318 July7.05.9×
GreenfieldMassachusetts, United States3 41.818 July7.15.9×
HartfordConnecticut, United States3 50.918 July8.75.9×
CoventryRhode Island, United States2 29.716 July5.25.7×
HaverhillMassachusetts, United States1 39.918 July7.05.7×
NewburghNew York, United States4 34.616 July6.15.7×
BrocktonMassachusetts, United States2 43.418 July7.75.6×
RochesterMinnesota, United States1 56.119 July10.15.6×
SpringfieldIllinois, United States2 51.419 July9.35.5×
LynnMassachusetts, United States2 38.318 July7.05.5×
Upper AltonIllinois, United States1 48.920 July9.35.3×
SalemVirginia, United States1 45.117 July8.65.2×
QuincyMassachusetts, United States2 35.818 July6.95.2×
PawtucketRhode Island, United States1 32.118 July6.25.2×
DerryNew Hampshire, United States2 36.518 July7.15.1×
BostonMassachusetts, United States2 39.318 July7.75.1×
AndersonIndiana, United States2 43.619 July8.85.0×
BloomingtonIndiana, United States2 40.120 July8.24.9×
ProvidenceRhode Island, United States1 33.718 July6.94.9×
KeeneNew Hampshire, United States2 34.618 July7.14.9×
Terre HauteIndiana, United States2 47.419 July10.14.7×
PittsfieldMassachusetts, United States3 36.616 July7.84.7×
Fall RiverMassachusetts, United States3 33.118 July7.14.7×
LafayetteIndiana, United States2 41.519 July9.14.6×
KokomoIndiana, United States3 40.119 July8.84.6×
LexingtonMassachusetts, United States3 55.118 July12.24.5×
IndianapolisIndiana, United States2 48.019 July11.04.4×
AlbanyNew York, United States3 42.116 July9.74.3×
MuscatineIowa, United States1 29.520 July6.84.3×
Granite CityIllinois, United States1 42.320 July10.24.1×
FishersIndiana, United States2 41.719 July10.14.1×
MuncieIndiana, United States3 39.219 July9.54.1×
PortsmouthNew Hampshire, United States1 30.518 July7.64.0×
LemayMissouri, United States1 31.720 July7.94.0×
University CityMissouri, United States1 29.620 July7.53.9×
MiddletownOhio, United States3 43.419 July11.63.7×
RutlandVermont, United States1 30.018 July8.23.7×
East Saint LouisIllinois, United States1 36.620 July10.13.6×
PortlandMaine, United States1 32.618 July9.03.6×
ColumbusIndiana, United States2 31.119 July8.63.6×
LebanonOhio, United States2 28.919 July8.03.6×
AshlandKentucky, United States1 28.820 July8.13.6×
Fort ThomasKentucky, United States2 28.119 July8.03.5×
PortsmouthOhio, United States2 34.220 July9.93.5×
MasonOhio, United States2 29.319 July8.53.4×
St. LouisMissouri, United States1 33.420 July9.73.4×
CharlestonWest Virginia, United States1 26.620 July8.33.2×
NorwoodOhio, United States2 35.319 July11.33.1×
MankatoMinnesota, United States1 29.919 July9.63.1×
JasperIndiana, United States1 28.020 July9.13.1×
GranbyQuebec, Canada1 25.518 July8.82.9×
CincinnatiOhio, United States2 33.019 July11.52.9×
NepeanOntario, Canada2 41.912 July14.82.8×
Wake ForestNorth Carolina, United States2 35.117 July12.62.8×
Winston-SalemNorth Carolina, United States1 25.318 July9.22.8×

Daily means in µg/m³. Usual: the city's median for this time of year (its days within 21 days of the date, every year, leaving out the week around it). Above usual: its highest day against that.

Against other episodes in the United States and Canada

Number 2 of 106 episodes in the United States and Canada since our records began, by cities reached.

Bars: cities reached; colour: the level of the episode's highest daily reading. All 106.

Use this page

SmogRank, North-eastern United States and Canada, July 2026: 264 cities with PM2.5 at twice their usual or more, 14 to 21 July 2026, smogrank.com/episodes/2026-07-north-eastern-united-states-and-canada (accessed 2 October 2026).

Download top 10 (PNG)

You're welcome to reuse a single chart, image or figure with this citation and a link. Terms.

An episode is a run of days when many cities close to each other (four or more within 350 km on a day, 8 or more in all) each had a daily PM2.5 mean of at least 25 µg/m³ and at least 2 times their usual for that time of year. Found in our own measurements, not picked by hand. How we find episodes. Values are each city's daily mean of its own monitors; causes are the usual kinds for a pattern like this, not a confirmed source.