SmogRank / Episodes / United States

United States and Canada, July 2023

For 6 days, from 14 to 19 July 2023, 322 cities in the United States and Canada had PM2.5 at least twice their usual for the time of year. The worst reading was Edmonton, Alberta, Canada: 202.0 µg/m³ on 15 July, about 17× its usual 12.1. Ended 19 July.

Likely smoke from firesFires were detected within 300 km of the city on 27% of the counted city-days and smoke was mapped over the city on 95%. Satellites see crop, field and forest fires alike, so this doesn't say which burned.
Cities reached322in 2 countries
Days614 to 19 July 2023
Worst day17 July198 cities counted
Furthest above usual23×Grande Prairie

Day by day

17 July 198 cities at twice their usual or more
MinneapolisBrainerdDetroit LakesBeatriceSaint JosephCedar RapidsGrand IslandKearneyCloquetLibertyKansas CityKansas CityTopekaOlatheRaymoreVirginiaClintonChanuteWichitaDerbyHaysvilleBismarckSpringfieldMiamiLemayPonca CityTulsaSpringdaleZionJenksWinthrop HarborGlenpoolBrandonFort SmithEdmondOklahoma CityMooreMcAlesterScottsbluffAdaLittle RockHudsonvilleLawtonEvansvilleDyersburgJenisonGrand RapidsMarionWest MemphisJasperRanchettesBartlettCheyenneGreeleyHernandoTexarkanaColumbusFort CollinsThorntonLongmontDentonDenverAmarilloLaramieBoulderKen CarylColorado SpringsLansingClevelandNew AlbanyDallasSaginawRiver OaksFort WorthShreveportCasperNashvilleSault Ste. MarieBay CityCorsicanaFlintSharonvilleMasonSheridanLubbockLacy-LakeviewRedfordTaylorDecaturJacksonNew BaltimoreBeltonPort HuronSarniaCollege StationFlin FlonPortsmouthConroeRivertonGadsdenWells BranchHobbsSulphurPrienAustinHattiesburgLanderLafayetteOdessaBaton RougePort ArthurHighlandsHoustonBaytownDeer ParkPasadenaMission BendLa PorteShaker HeightsMissouri CityCodySeabrookGrand JunctionRio RanchoRock SpringsAlbuquerqueGalvestonLive OakMontgomeryWindcrestHelotesPrince AlbertKennerSan AntonioSchrieverWavelandNew OrleansGulfportChalmetteCharlestonGreater SudburyPrichardVernalPascagoulaKitchenerFairhopeGuelphColumbusRooseveltFerry PassParry SoundMidwayBarrieEagle PassNewmarketBozemanNorth BayLas CrucesSocorroEl PasoCiudad JuárezSunland ParkBrooklinCondaRexburgSmithfieldPrestonSpanish ForkOremIdaho FallsCedar HillsHighlandBountifulNorth OgdenMillcreekSalt Lake CityRouyn-NorandaWest JordanWest Valley CityTallahasseeHerrimanMagnaHelenaHelena Valley West CentralPocatelloStansbury parkTooeleButteRockvilleRichmondCedar CityConwayRed HillJacksonvilleGainesvilleRoanoke RapidsHopewellFruit CoveMissoulaHurricanePonte Vedra BeachApache JunctionTwin FallsCasas AdobesTucsonOcalaMesaMaranaTempeGreen ValleyPhoenixCasa GrandeOttawaGlendaleMurraysvilleCambridgeEast LakeNogalesNogalesPoquosonBearEast HamptonMesquiteChesapeakeClaymontDaytona BeachDoverChesterSeafordLake MaryWinter ParkLakelandPennsaukenSouth VinelandEwingSherwood ParkTrentonBoulder CityNew BrunswickGarden CityHendersonPleasantvilleSmithvilleMeridianLindenLas VegasElizabethAtlantic CityPalm BayBayonneSpring ValleyToms RiverNampaJersey CityEnterpriseSummerlin SouthNew York CityFort LeeDorvalWhite PlainsRivière-des-Prairies–Pointe-aux-TremblesHempsteadSandpointDanburyCoeur d'AleneLewistonCrestonMoscowYumaBridgeportPullmanWaterburyHolbrookSpokane ValleyNew HavenMeadSpokaneHartfordCheneyAirway HeightsBrawleyLa GrandeMexicaliCalexicoEl CentroIndioNew LondonWalla WallaEdsonCoventryWest GreenwichBanningPendletonRidgecrestVictorvilleProvidencePawtucketFinleyPascoTemeculaFontanaRiversideTri-CitiesFall RiverLake ElsinoreHermistonPowayEl CajonJurupa ValleyBrocktonQuincyOntarioMoses LakeTijuanaChula VistaOceansideSan DiegoGlendoraPortsmouthLancasterEphrataAnaheimProsserSpanish SpringsLa Crescenta-MontroseLos AngelesBurbankRenoComptonPortervilleQuincyCarson CityLong BeachSunnysideCarsonInglewoodSanta ClaritaHawthorneLomitaLewistonTorrancePentictonKelownaVisaliaSanta MonicaBakersfieldSouth Lake TahoeToppenishSimi ValleyAgouraTruckeeClovisFillmoreThousand OaksWenatcheeCorcoranHanfordFresnoYakimaAugustaEllensburgPrinevilleMaderaHuronMadrasRedmondMercedThe DallesSanta BarbaraBendNorth AuburnTurlockRancho MurietaFolsomHood RiverModestoLincolnRosevilleBangorAltamontGaltMantecaArden-ArcadeNipomoOrcuttStocktonParadiseAtascaderoArroyo GrandeSan Luis ObispoSacramentoOceanoLompocGuadalupeYuba CityGridleyTracyChicoHopeKing CityDavisWoodlandRio VistaHollisterEnumclawIssaquahColusaGilroyLivermoreAgassizRed BluffAndersonVacavilleWillowsPleasantonAuburnGreshamSalinasRentonBellevueReddingChilliwackMarysvilleMill PlainConcordSan JosePresque IsleSeattleOrchardsWhite CenterShorelineParklandYrekaTacomaMilwaukieAshlandSalmon CreekVancouverCanbySweet HomePortlandSan LeandroVallejoMount VernonNorth PortlandSanta CruzTalentSilvertonAbbotsfordStaytonBen LomondTigardRidgefieldOaklandBeavertonRedwood CityMedfordRichmondWoodburnBremertonBellinghamLyndenSan FranciscoLaceyCottage GroveOak HarborHillsboroLongviewSalemAnacortesSan RafaelEugeneAlbanyCentraliaChehalisPort TownsendSanta RosaForest GroveLangleyMcMinnvilleSebastopolCorvallisGrants PassSheltonDallasGreenPort CoquitlamCoquitlamStrawberry HillUkiahBurnabyDeltaNorth VancouverVancouverRichmondWhistlerWest VancouverVictoriaPort AngelesSquamishFrederictonLangfordAberdeenQuesnelGibsonsNorth CowichanDuncanCoos BayCrescent CityBrookingsSaint JohnNanaimoHarewoodPrince GeorgeLabrador CityMiramichiPort AlberniCourtenayMonctonCampbell RiverLexingtonSuperiorKalamazooDetroitDearbornDuluthWindsorPhiladelphiaYpsilantiJacksonLincoln ParkReginaBensalemTorontoSt. LouisGranite CityTrois-RivièresShawiniganMiltonOak LawnToledoBramptonJohnstownCornwallLake CityPatersonLondonHollandGreen BayScaggsvilleElkhartMilwaukeeCincinnatiColumbia FallsHendersonvilleScrantonArnoldPortlandLebanonWaukeshaHarrisburgBrossardChicagoEast Saint LouisL'Ancienne-LoretteNorwoodMiddletownBostonUniversity CitySouth MilwaukeeGreendaleBlaineMontréalQuébecWashingtonLa CrosseWest MifflinLincolnElktonGlasgowWilmingtonMississaugaSaguenaySchlusserCarlisleTarboroAlbanyMcCordsvilleFishersCheektowagaLynnAugustaWyomissingReadingChathamBrantfordGreat FallsSaskatoonSaint-Jean-sur-RichelieuEdmundstonNorristownSpringfieldPeterboroughNorth CharlestonDrummondvilleGranbyNew HollandHamiltonMcKeesportJefferson HillsMoundsvilleEstevanCookevilleBellevilleSherbrookeSouth LaurelYorkKingstonAltoonaAppletonWaterdownOakvilleWest FargoSouth BendPortageOmahaWheelingValley StationTecumsehWorcesterLondonderryDerryCastlegarFrostburgAllentownSpringfieldFlatwoodsIndianapolisHunt ValleyBaltimoreKennett SquareHighland HeightsFort ThomasNewarkMadisonLancasterFlorenceWilkinsburgTerre HauteNapervilleFranklin ParkBarabooState CollegeSandersvilleSaint AndrewsCaryNorthbrookSaint PaulKennedy TownshipSteubenvilleHalfwayHagerstownEdgewoodSt. ThomasSaint MatthewsRochesterBrunswickLowellClarksvilleOak GroveSaint CloudMonessenOwensboroBirminghamRockfordGaryLexington-FayetteColumbiaSaint MichaelJeffersonvilleKokomoKenmoreWareValdostaRose HillSt. CatharinesGreensboroJeffersontownLouisvilleLimaBellevueBethlehemTrussvilleLeedsLebanonPittsfieldJerseyvilleRutlandAtlantaDes PlainesPittsburghHammondNewburghNorth ChicopeeAshevilleElizabethtownCharlottesvillePaducahClaytonLexingtonMorrisvilleCalgaryHaverhillKingsportNorth AdamsSomersetAshlandAthensHueytownFairfieldBloomingtonLafayetteBuffaloDaytonPikevilleUticaPhenix CityHartfordLockwoodBillingsSavannahGreenvilleHickoryNew CityMount IvyVernonKeeneHarrimanWhite OakDentLewistownRaleighFayettevilleShakopeeSpartanburgColumbia CitySpringfieldCalumet CityWestervilleBlairWeirton HeightsRoanokeMaryvilleCharlotteNew BrightonEau ClaireAltoonaBeaver FallsClevelandCranbrookBenningtonDurhamAndersonChattanoogaGainesvilleSpringfieldEast RidgeFairviewBurnsvilleJolietLoudonGreenfieldAirdrieClemmonsCandler-McAfeeCantonNew AlbanyGahannaDublinEast ChicagoWarrenDentsvilleHazardBurlingtonAlbanyApple ValleyRochesterWinston-SalemSyracuseDecaturMaconGilletteLawrencevilleWaterlooYoungstownHuntsvilleWatertownKnoxvilleMiddlesboroHermitageSavoyRapid CityGreenvilleAkronLethbridgeWarner RobinsDavenportMedinaPainesvilleWarrensville HeightsBraidwoodMolineIowa CityAthensAberdeenErieDes MoinesAnkenyMcDonoughLaconiaDrayton ValleyMuscatineBloomingtonKamloopsGrand CentreMarshallRed DeerBrookingsFort McMurrayMiles CitySioux FallsSt. AlbertMedicine HatVermillionFort St. JohnHavreEdmontonPierreFort SaskatchewanSwift CurrentWilliams LakeGrande Prairie
11 Jul1213141516171819202122
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

BrookingsBrookings, 11 July: 1.2 µg/m³Brookings, 12 July: 2.4 µg/m³Brookings, 13 July: 3.8 µg/m³Brookings, 14 July: 27.2 µg/m³, 4.1× its usual 6.7Brookings, 15 July: 71.6 µg/m³, 11× its usual 6.7Brookings, 16 July: 49.9 µg/m³, 7.4× its usual 6.7Brookings, 17 July: 3.7 µg/m³Brookings, 18 July: 4.9 µg/m³Brookings, 19 July: 5.1 µg/m³Brookings, 20 July: 5.6 µg/m³Brookings, 21 July: 8.5 µg/m³Brookings, 22 July: 11.2 µg/m³EdmontonEdmonton, 11 July: 10.4 µg/m³Edmonton, 12 July: 35.1 µg/m³Edmonton, 13 July: 75.9 µg/m³Edmonton, 14 July: no readingEdmonton, 15 July: 202.0 µg/m³, 17× its usual 12.1Edmonton, 16 July: 111.0 µg/m³, 9.2× its usual 12.1Edmonton, 17 July: 45.7 µg/m³Edmonton, 18 July: 25.7 µg/m³Edmonton, 19 July: 22.8 µg/m³Edmonton, 20 July: 42.3 µg/m³Edmonton, 21 July: 56.9 µg/m³Edmonton, 22 July: 49.1 µg/m³Fort SaskatchewanFort Saskatchewan, 11 July: 6.7 µg/m³Fort Saskatchewan, 12 July: 23.7 µg/m³Fort Saskatchewan, 13 July: 72.3 µg/m³Fort Saskatchewan, 14 July: no readingFort Saskatchewan, 15 July: 180.0 µg/m³, 18× its usual 10.1Fort Saskatchewan, 16 July: 102.0 µg/m³, 10× its usual 10.2Fort Saskatchewan, 17 July: 30.7 µg/m³Fort Saskatchewan, 18 July: 17.8 µg/m³Fort Saskatchewan, 19 July: 14.5 µg/m³Fort Saskatchewan, 20 July: 30.2 µg/m³Fort Saskatchewan, 21 July: 47.6 µg/m³Fort Saskatchewan, 22 July: 38.8 µg/m³Swift CurrentSwift Current, 11 July: 5.5 µg/m³Swift Current, 12 July: 6.4 µg/m³Swift Current, 13 July: 29.6 µg/m³Swift Current, 14 July: no readingSwift Current, 15 July: 159.0 µg/m³, 19× its usual 8.5Swift Current, 16 July: 65.2 µg/m³, 7.6× its usual 8.6Swift Current, 17 July: 24.3 µg/m³Swift Current, 18 July: 18.1 µg/m³Swift Current, 19 July: 17.7 µg/m³Swift Current, 20 July: 19.9 µg/m³Swift Current, 21 July: 21.6 µg/m³Swift Current, 22 July: 26.3 µg/m³Grande PrairieGrande Prairie, 11 July: 66.2 µg/m³Grande Prairie, 12 July: 123.0 µg/m³Grande Prairie, 13 July: no readingGrande Prairie, 14 July: no readingGrande Prairie, 15 July: 94.9 µg/m³, 14× its usual 6.6Grande Prairie, 16 July: 154.0 µg/m³, 23× its usual 6.6Grande Prairie, 17 July: 34.7 µg/m³Grande Prairie, 18 July: 8.9 µg/m³Grande Prairie, 19 July: 21.6 µg/m³Grande Prairie, 20 July: 67.0 µg/m³Grande Prairie, 21 July: 59.8 µg/m³Grande Prairie, 22 July: 11.1 µg/m³Fort McMurrayFort McMurray, 11 July: 5.1 µg/m³Fort McMurray, 12 July: 28.8 µg/m³Fort McMurray, 13 July: 169.5 µg/m³Fort McMurray, 14 July: no readingFort McMurray, 15 July: 144.5 µg/m³, 11× its usual 12.8Fort McMurray, 16 July: 23.7 µg/m³Fort McMurray, 17 July: 25.6 µg/m³Fort McMurray, 18 July: 44.8 µg/m³Fort McMurray, 19 July: 23.6 µg/m³Fort McMurray, 20 July: 22.1 µg/m³Fort McMurray, 21 July: 42.8 µg/m³Fort McMurray, 22 July: 94.4 µg/m³Williams LakeWilliams Lake, 11 July: 12.2 µg/m³Williams Lake, 12 July: 45.2 µg/m³Williams Lake, 13 July: 17.6 µg/m³Williams Lake, 14 July: no readingWilliams Lake, 15 July: 112.0 µg/m³, 22× its usual 4.7Williams Lake, 16 July: 18.0 µg/m³Williams Lake, 17 July: 13.1 µg/m³Williams Lake, 18 July: 2.7 µg/m³Williams Lake, 19 July: 7.5 µg/m³Williams Lake, 20 July: 3.4 µg/m³Williams Lake, 21 July: 16.0 µg/m³Williams Lake, 22 July: 17.4 µg/m³St. AlbertSt. Albert, 11 July: 4.8 µg/m³St. Albert, 12 July: 21.9 µg/m³St. Albert, 13 July: 38.4 µg/m³St. Albert, 14 July: no readingSt. Albert, 15 July: 112.0 µg/m³, 13× its usual 8.8St. Albert, 16 July: 50.3 µg/m³, 5.7× its usual 8.8St. Albert, 17 July: 23.3 µg/m³St. Albert, 18 July: 8.7 µg/m³St. Albert, 19 July: 12.2 µg/m³St. Albert, 20 July: 24.7 µg/m³St. Albert, 21 July: 29.8 µg/m³St. Albert, 22 July: 22.7 µg/m³Grand CentreGrand Centre, 11 July: 4.2 µg/m³Grand Centre, 12 July: 6.8 µg/m³Grand Centre, 13 July: no readingGrand Centre, 14 July: no readingGrand Centre, 15 July: 99.2 µg/m³, 9.3× its usual 10.7Grand Centre, 16 July: 23.9 µg/m³Grand Centre, 17 July: 14.9 µg/m³Grand Centre, 18 July: 16.6 µg/m³Grand Centre, 19 July: 25.6 µg/m³Grand Centre, 20 July: 25.7 µg/m³Grand Centre, 21 July: 44.7 µg/m³Grand Centre, 22 July: 52.5 µg/m³Medicine HatMedicine Hat, 11 July: 5.8 µg/m³Medicine Hat, 12 July: 9.0 µg/m³Medicine Hat, 13 July: 29.1 µg/m³Medicine Hat, 14 July: no readingMedicine Hat, 15 July: 70.7 µg/m³, 10× its usual 7.0Medicine Hat, 16 July: 92.0 µg/m³, 13× its usual 7.1Medicine Hat, 17 July: 30.4 µg/m³Medicine Hat, 18 July: 3.5 µg/m³Medicine Hat, 19 July: 9.8 µg/m³Medicine Hat, 20 July: 12.1 µg/m³Medicine Hat, 21 July: 10.7 µg/m³Medicine Hat, 22 July: no readingRed DeerRed Deer, 11 July: 7.6 µg/m³Red Deer, 12 July: 32.2 µg/m³Red Deer, 13 July: 60.5 µg/m³Red Deer, 14 July: no readingRed Deer, 15 July: 91.9 µg/m³, 9.8× its usual 9.4Red Deer, 16 July: 57.7 µg/m³, 6.1× its usual 9.4Red Deer, 17 July: 29.3 µg/m³Red Deer, 18 July: 10.8 µg/m³Red Deer, 19 July: 16.8 µg/m³Red Deer, 20 July: 17.3 µg/m³Red Deer, 21 July: 20.6 µg/m³Red Deer, 22 July: 17.3 µg/m³Fort St. JohnFort St. John, 11 July: 68.6 µg/m³Fort St. John, 12 July: 45.2 µg/m³Fort St. John, 13 July: 33.6 µg/m³Fort St. John, 14 July: no readingFort St. John, 15 July: 82.2 µg/m³, 14× its usual 6.0Fort St. John, 16 July: 90.8 µg/m³, 15× its usual 5.9Fort St. John, 17 July: 26.3 µg/m³Fort St. John, 18 July: 8.8 µg/m³Fort St. John, 19 July: 38.6 µg/m³Fort St. John, 20 July: 53.4 µg/m³Fort St. John, 21 July: 55.4 µg/m³Fort St. John, 22 July: 13.3 µg/m³PierrePierre, 11 July: 2.8 µg/m³Pierre, 12 July: 2.4 µg/m³Pierre, 13 July: 2.9 µg/m³Pierre, 14 July: no readingPierre, 15 July: 86.8 µg/m³, 17× its usual 4.7Pierre, 16 July: 75.6 µg/m³, 15× its usual 4.8Pierre, 17 July: 3.7 µg/m³Pierre, 18 July: 4.5 µg/m³Pierre, 19 July: 7.3 µg/m³Pierre, 20 July: 6.7 µg/m³Pierre, 21 July: 7.5 µg/m³Pierre, 22 July: 7.8 µg/m³Miles CityMiles City, 11 July: 17.9 µg/m³Miles City, 12 July: 7.5 µg/m³Miles City, 13 July: 11.6 µg/m³Miles City, 14 July: no readingMiles City, 15 July: 76.0 µg/m³, 10× its usual 7.6Miles City, 16 July: 86.3 µg/m³, 11× its usual 7.6Miles City, 17 July: 41.0 µg/m³Miles City, 18 July: 13.2 µg/m³Miles City, 19 July: 11.6 µg/m³Miles City, 20 July: 10.6 µg/m³Miles City, 21 July: 12.6 µg/m³Miles City, 22 July: 9.4 µg/m³HavreHavre, 11 July: 7.6 µg/m³Havre, 12 July: 6.5 µg/m³Havre, 13 July: 17.3 µg/m³Havre, 14 July: no readingHavre, 15 July: 60.4 µg/m³, 12× its usual 4.9Havre, 16 July: 86.2 µg/m³, 16× its usual 5.3Havre, 17 July: 39.6 µg/m³Havre, 18 July: 6.2 µg/m³Havre, 19 July: 10.0 µg/m³Havre, 20 July: 12.8 µg/m³Havre, 21 July: 10.9 µg/m³Havre, 22 July: 7.9 µg/m³KamloopsKamloops, 11 July: 17.8 µg/m³Kamloops, 12 July: 8.5 µg/m³Kamloops, 13 July: 13.9 µg/m³Kamloops, 14 July: no readingKamloops, 15 July: 76.2 µg/m³, 9.1× its usual 8.4Kamloops, 16 July: 8.8 µg/m³Kamloops, 17 July: 6.6 µg/m³Kamloops, 18 July: 7.5 µg/m³Kamloops, 19 July: 8.8 µg/m³Kamloops, 20 July: 9.1 µg/m³Kamloops, 21 July: 11.0 µg/m³Kamloops, 22 July: 15.9 µg/m³VermillionVermillion, 11 July: 4.7 µg/m³Vermillion, 12 July: 2.1 µg/m³Vermillion, 13 July: 3.1 µg/m³Vermillion, 14 July: no readingVermillion, 15 July: 46.5 µg/m³, 8.6× its usual 5.4Vermillion, 16 July: 76.1 µg/m³, 14× its usual 5.5Vermillion, 17 July: 19.3 µg/m³Vermillion, 18 July: 4.9 µg/m³Vermillion, 19 July: 6.4 µg/m³Vermillion, 20 July: 7.5 µg/m³Vermillion, 21 July: 8.4 µg/m³Vermillion, 22 July: 10.7 µg/m³MarshallMarshall, 11 July: 5.4 µg/m³Marshall, 12 July: 4.1 µg/m³Marshall, 13 July: 5.3 µg/m³Marshall, 14 July: no readingMarshall, 15 July: 75.8 µg/m³, 9.8× its usual 7.7Marshall, 16 July: 50.3 µg/m³, 6.6× its usual 7.6Marshall, 17 July: 6.0 µg/m³Marshall, 18 July: 8.0 µg/m³Marshall, 19 July: 9.0 µg/m³Marshall, 20 July: 11.7 µg/m³Marshall, 21 July: 11.4 µg/m³Marshall, 22 July: 14.7 µg/m³AnkenyAnkeny, 11 July: 9.7 µg/m³Ankeny, 12 July: 5.2 µg/m³Ankeny, 13 July: 5.3 µg/m³Ankeny, 14 July: 5.5 µg/m³Ankeny, 15 July: 46.3 µg/m³, 4.9× its usual 9.4Ankeny, 16 July: 68.5 µg/m³, 7.6× its usual 9.0Ankeny, 17 July: 20.3 µg/m³Ankeny, 18 July: 7.5 µg/m³Ankeny, 19 July: 14.6 µg/m³Ankeny, 20 July: 11.1 µg/m³Ankeny, 21 July: 9.5 µg/m³Ankeny, 22 July: 13.4 µg/m³Sioux FallsSioux Falls, 11 July: 3.8 µg/m³Sioux Falls, 12 July: 1.1 µg/m³Sioux Falls, 13 July: 2.2 µg/m³Sioux Falls, 14 July: 11.3 µg/m³Sioux Falls, 15 July: 63.7 µg/m³, 11× its usual 5.8Sioux Falls, 16 July: 66.6 µg/m³, 12× its usual 5.6Sioux Falls, 17 July: 4.4 µg/m³Sioux Falls, 18 July: 3.2 µg/m³Sioux Falls, 19 July: 3.8 µg/m³Sioux Falls, 20 July: 5.5 µg/m³Sioux Falls, 21 July: 4.6 µg/m³Sioux Falls, 22 July: 4.2 µg/m³Des MoinesDes Moines, 11 July: 9.4 µg/m³Des Moines, 12 July: 5.3 µg/m³Des Moines, 13 July: 3.7 µg/m³Des Moines, 14 July: 3.6 µg/m³Des Moines, 15 July: 44.4 µg/m³, 5.2× its usual 8.6Des Moines, 16 July: 65.3 µg/m³, 7.6× its usual 8.6Des Moines, 17 July: 18.6 µg/m³Des Moines, 18 July: 5.6 µg/m³Des Moines, 19 July: 12.2 µg/m³Des Moines, 20 July: 8.9 µg/m³Des Moines, 21 July: 6.5 µg/m³Des Moines, 22 July: 10.5 µg/m³Iowa CityIowa City, 11 July: 9.7 µg/m³Iowa City, 12 July: 4.5 µg/m³Iowa City, 13 July: 3.5 µg/m³Iowa City, 14 July: 4.8 µg/m³Iowa City, 15 July: 37.0 µg/m³, 4.3× its usual 8.7Iowa City, 16 July: 62.4 µg/m³, 7.1× its usual 8.8Iowa City, 17 July: 25.4 µg/m³, 2.9× its usual 8.8Iowa City, 18 July: 8.6 µg/m³Iowa City, 19 July: 9.8 µg/m³Iowa City, 20 July: 12.3 µg/m³Iowa City, 21 July: 11.5 µg/m³Iowa City, 22 July: 14.2 µg/m³MolineMoline, 11 July: 10.4 µg/m³Moline, 12 July: 5.1 µg/m³Moline, 13 July: 5.0 µg/m³Moline, 14 July: 5.4 µg/m³Moline, 15 July: 34.7 µg/m³, 4.0× its usual 8.6Moline, 16 July: 60.9 µg/m³, 7.1× its usual 8.6Moline, 17 July: 27.0 µg/m³, 3.1× its usual 8.7Moline, 18 July: 7.8 µg/m³Moline, 19 July: 10.3 µg/m³Moline, 20 July: 13.0 µg/m³Moline, 21 July: 8.2 µg/m³Moline, 22 July: 13.2 µg/m³Drayton ValleyDrayton Valley, 11 July: 9.4 µg/m³Drayton Valley, 12 July: 36.9 µg/m³Drayton Valley, 13 July: 37.5 µg/m³Drayton Valley, 14 July: no readingDrayton Valley, 15 July: 60.8 µg/m³, 7.8× its usual 7.8Drayton Valley, 16 July: 45.2 µg/m³, 5.8× its usual 7.8Drayton Valley, 17 July: 36.3 µg/m³Drayton Valley, 18 July: 11.3 µg/m³Drayton Valley, 19 July: 16.7 µg/m³Drayton Valley, 20 July: 20.5 µg/m³Drayton Valley, 21 July: 15.3 µg/m³Drayton Valley, 22 July: 11.5 µg/m³DavenportDavenport, 11 July: 9.8 µg/m³Davenport, 12 July: 4.6 µg/m³Davenport, 13 July: 4.4 µg/m³Davenport, 14 July: 5.2 µg/m³Davenport, 15 July: 34.6 µg/m³, 4.0× its usual 8.6Davenport, 16 July: 59.0 µg/m³, 6.9× its usual 8.6Davenport, 17 July: 27.9 µg/m³, 3.2× its usual 8.7Davenport, 18 July: 8.0 µg/m³Davenport, 19 July: 10.7 µg/m³Davenport, 20 July: 12.9 µg/m³Davenport, 21 July: 9.0 µg/m³Davenport, 22 July: 13.1 µg/m³Rapid CityRapid City, 11 July: 7.4 µg/m³Rapid City, 12 July: 12.0 µg/m³Rapid City, 13 July: 9.7 µg/m³Rapid City, 14 July: 26.5 µg/m³Rapid City, 15 July: 47.1 µg/m³, 5.7× its usual 8.3Rapid City, 16 July: 55.4 µg/m³, 6.6× its usual 8.4Rapid City, 17 July: 51.6 µg/m³Rapid City, 18 July: 16.3 µg/m³Rapid City, 19 July: 13.6 µg/m³Rapid City, 20 July: 14.9 µg/m³Rapid City, 21 July: 13.5 µg/m³Rapid City, 22 July: 8.2 µg/m³MuscatineMuscatine, 11 July: 8.2 µg/m³Muscatine, 12 July: 3.7 µg/m³Muscatine, 13 July: 5.5 µg/m³Muscatine, 14 July: no readingMuscatine, 15 July: 28.9 µg/m³, 4.4× its usual 6.6Muscatine, 16 July: 53.2 µg/m³, 8.1× its usual 6.6Muscatine, 17 July: 25.0 µg/m³, 3.8× its usual 6.6Muscatine, 18 July: 6.3 µg/m³Muscatine, 19 July: 10.6 µg/m³Muscatine, 20 July: 9.5 µg/m³Muscatine, 21 July: 7.9 µg/m³Muscatine, 22 July: 10.4 µg/m³BurnsvilleBurnsville, 11 July: 4.1 µg/m³Burnsville, 12 July: 6.8 µg/m³Burnsville, 13 July: 9.2 µg/m³Burnsville, 14 July: 13.3 µg/m³Burnsville, 15 July: 52.7 µg/m³, 5.5× its usual 9.6Burnsville, 16 July: 20.2 µg/m³Burnsville, 17 July: 5.6 µg/m³Burnsville, 18 July: 8.2 µg/m³Burnsville, 19 July: 8.2 µg/m³Burnsville, 20 July: 8.5 µg/m³Burnsville, 21 July: 11.6 µg/m³Burnsville, 22 July: 14.5 µg/m³LethbridgeLethbridge, 11 July: no readingLethbridge, 12 July: no readingLethbridge, 13 July: 19.4 µg/m³Lethbridge, 14 July: no readingLethbridge, 15 July: 46.9 µg/m³, 6.3× its usual 7.5Lethbridge, 16 July: 51.9 µg/m³, 6.8× its usual 7.6Lethbridge, 17 July: 17.1 µg/m³Lethbridge, 18 July: 5.6 µg/m³Lethbridge, 19 July: 12.6 µg/m³Lethbridge, 20 July: 13.2 µg/m³Lethbridge, 21 July: 12.1 µg/m³Lethbridge, 22 July: 8.2 µg/m³ShakopeeShakopee, 11 July: 4.3 µg/m³Shakopee, 12 July: 6.9 µg/m³Shakopee, 13 July: 8.3 µg/m³Shakopee, 14 July: no readingShakopee, 15 July: 50.6 µg/m³, 5.3× its usual 9.6Shakopee, 16 July: 19.7 µg/m³Shakopee, 17 July: 5.6 µg/m³Shakopee, 18 July: 8.6 µg/m³Shakopee, 19 July: 7.7 µg/m³Shakopee, 20 July: 8.6 µg/m³Shakopee, 21 July: 11.8 µg/m³Shakopee, 22 July: 15.5 µg/m³BloomingtonBloomington, 11 July: 9.0 µg/m³Bloomington, 12 July: 8.0 µg/m³Bloomington, 13 July: 4.0 µg/m³Bloomington, 14 July: no readingBloomington, 15 July: 18.3 µg/m³Bloomington, 16 July: 74.0 µg/m³, 8.8× its usual 8.4Bloomington, 17 July: 38.0 µg/m³, 4.5× its usual 8.4Bloomington, 18 July: 7.1 µg/m³Bloomington, 19 July: 11.7 µg/m³Bloomington, 20 July: 11.5 µg/m³Bloomington, 21 July: 5.9 µg/m³Bloomington, 22 July: 8.1 µg/m³WarrenWarren, 11 July: 12.0 µg/m³Warren, 12 July: 13.2 µg/m³Warren, 13 July: 8.4 µg/m³Warren, 14 July: 6.7 µg/m³Warren, 15 July: 9.2 µg/m³Warren, 16 July: 27.4 µg/m³, 2.5× its usual 11.1Warren, 17 July: 63.6 µg/m³, 5.8× its usual 11.0Warren, 18 July: 26.3 µg/m³, 2.4× its usual 10.9Warren, 19 July: 6.1 µg/m³Warren, 20 July: 12.3 µg/m³Warren, 21 July: 6.4 µg/m³Warren, 22 July: 12.5 µg/m³ClevelandCleveland, 11 July: 11.7 µg/m³Cleveland, 12 July: 12.0 µg/m³Cleveland, 13 July: 6.5 µg/m³Cleveland, 14 July: 9.0 µg/m³Cleveland, 15 July: 9.9 µg/m³Cleveland, 16 July: 34.4 µg/m³, 3.0× its usual 11.5Cleveland, 17 July: 61.3 µg/m³, 5.4× its usual 11.3Cleveland, 18 July: 20.9 µg/m³Cleveland, 19 July: 8.4 µg/m³Cleveland, 20 July: 11.8 µg/m³Cleveland, 21 July: 7.8 µg/m³Cleveland, 22 July: 12.6 µg/m³CantonCanton, 11 July: 15.1 µg/m³Canton, 12 July: 14.6 µg/m³Canton, 13 July: 8.2 µg/m³Canton, 14 July: 7.2 µg/m³Canton, 15 July: 8.9 µg/m³Canton, 16 July: 29.8 µg/m³, 2.7× its usual 10.9Canton, 17 July: 61.0 µg/m³, 5.6× its usual 10.9Canton, 18 July: 24.7 µg/m³Canton, 19 July: 7.8 µg/m³Canton, 20 July: 11.7 µg/m³Canton, 21 July: 7.6 µg/m³Canton, 22 July: 14.9 µg/m³MedinaMedina, 11 July: 9.1 µg/m³Medina, 12 July: 11.0 µg/m³Medina, 13 July: 5.7 µg/m³Medina, 14 July: 5.5 µg/m³Medina, 15 July: 8.8 µg/m³Medina, 16 July: 31.9 µg/m³, 3.6× its usual 8.9Medina, 17 July: 60.4 µg/m³, 6.9× its usual 8.8Medina, 18 July: 22.3 µg/m³Medina, 19 July: 5.3 µg/m³Medina, 20 July: 9.7 µg/m³Medina, 21 July: 5.8 µg/m³Medina, 22 July: 8.3 µg/m³WestervilleWesterville, 11 July: 12.9 µg/m³Westerville, 12 July: 12.8 µg/m³Westerville, 13 July: 9.5 µg/m³Westerville, 14 July: 7.2 µg/m³Westerville, 15 July: 8.9 µg/m³Westerville, 16 July: 29.7 µg/m³, 2.7× its usual 11.2Westerville, 17 July: 59.2 µg/m³, 5.3× its usual 11.1Westerville, 18 July: 23.0 µg/m³Westerville, 19 July: 18.4 µg/m³Westerville, 20 July: 11.4 µg/m³Westerville, 21 July: 7.3 µg/m³Westerville, 22 July: 9.5 µg/m³Warrensville HeightsWarrensville Heights, 11 July: 9.8 µg/m³Warrensville Heights, 12 July: 10.6 µg/m³Warrensville Heights, 13 July: 6.1 µg/m³Warrensville Heights, 14 July: no readingWarrensville Heights, 15 July: 7.8 µg/m³Warrensville Heights, 16 July: 33.1 µg/m³, 3.9× its usual 8.4Warrensville Heights, 17 July: 59.0 µg/m³, 7.0× its usual 8.4Warrensville Heights, 18 July: 20.7 µg/m³Warrensville Heights, 19 July: 4.6 µg/m³Warrensville Heights, 20 July: 9.5 µg/m³Warrensville Heights, 21 July: 6.6 µg/m³Warrensville Heights, 22 July: 10.0 µg/m³BraidwoodBraidwood, 11 July: 8.8 µg/m³Braidwood, 12 July: 6.1 µg/m³Braidwood, 13 July: 4.3 µg/m³Braidwood, 14 July: no readingBraidwood, 15 July: 15.6 µg/m³Braidwood, 16 July: 58.1 µg/m³, 7.1× its usual 8.2Braidwood, 17 July: 31.3 µg/m³, 3.8× its usual 8.2Braidwood, 18 July: 6.5 µg/m³Braidwood, 19 July: 6.7 µg/m³Braidwood, 20 July: 9.5 µg/m³Braidwood, 21 July: 6.4 µg/m³Braidwood, 22 July: 9.1 µg/m³YoungstownYoungstown, 11 July: 11.5 µg/m³Youngstown, 12 July: 11.7 µg/m³Youngstown, 13 July: 7.7 µg/m³Youngstown, 14 July: 6.1 µg/m³Youngstown, 15 July: 8.4 µg/m³Youngstown, 16 July: 25.4 µg/m³, 2.7× its usual 9.5Youngstown, 17 July: 58.0 µg/m³, 6.1× its usual 9.5Youngstown, 18 July: 24.0 µg/m³Youngstown, 19 July: 7.6 µg/m³Youngstown, 20 July: 10.9 µg/m³Youngstown, 21 July: 5.7 µg/m³Youngstown, 22 July: 10.9 µg/m³JolietJoliet, 11 July: 10.9 µg/m³Joliet, 12 July: 6.2 µg/m³Joliet, 13 July: 6.0 µg/m³Joliet, 14 July: 6.6 µg/m³Joliet, 15 July: 20.3 µg/m³Joliet, 16 July: 57.5 µg/m³, 5.5× its usual 10.4Joliet, 17 July: 29.4 µg/m³, 2.8× its usual 10.5Joliet, 18 July: 7.8 µg/m³Joliet, 19 July: 8.9 µg/m³Joliet, 20 July: 12.0 µg/m³Joliet, 21 July: 8.4 µg/m³Joliet, 22 July: 12.0 µg/m³AkronAkron, 11 July: 9.9 µg/m³Akron, 12 July: 10.3 µg/m³Akron, 13 July: 5.3 µg/m³Akron, 14 July: 6.0 µg/m³Akron, 15 July: 7.4 µg/m³Akron, 16 July: 27.6 µg/m³, 3.2× its usual 8.7Akron, 17 July: 56.2 µg/m³, 6.7× its usual 8.4Akron, 18 July: 22.9 µg/m³Akron, 19 July: 5.3 µg/m³Akron, 20 July: 9.2 µg/m³Akron, 21 July: 6.4 µg/m³Akron, 22 July: 10.4 µg/m³DecaturDecatur, 11 July: 10.5 µg/m³Decatur, 12 July: 10.9 µg/m³Decatur, 13 July: 4.3 µg/m³Decatur, 14 July: 7.2 µg/m³Decatur, 15 July: 16.1 µg/m³Decatur, 16 July: 56.0 µg/m³, 6.0× its usual 9.3Decatur, 17 July: 26.8 µg/m³, 2.9× its usual 9.1Decatur, 18 July: 14.9 µg/m³Decatur, 19 July: 13.4 µg/m³Decatur, 20 July: 11.3 µg/m³Decatur, 21 July: 6.9 µg/m³Decatur, 22 July: 7.7 µg/m³Calumet CityCalumet City, 11 July: 10.4 µg/m³Calumet City, 12 July: 7.2 µg/m³Calumet City, 13 July: 8.6 µg/m³Calumet City, 14 July: 8.0 µg/m³Calumet City, 15 July: 17.2 µg/m³Calumet City, 16 July: 55.8 µg/m³, 5.3× its usual 10.5Calumet City, 17 July: 29.1 µg/m³, 2.8× its usual 10.4Calumet City, 18 July: 9.8 µg/m³Calumet City, 19 July: 10.1 µg/m³Calumet City, 20 July: 12.0 µg/m³Calumet City, 21 July: 8.2 µg/m³Calumet City, 22 July: 13.6 µg/m³SavoySavoy, 11 July: 8.9 µg/m³Savoy, 12 July: 9.2 µg/m³Savoy, 13 July: 3.5 µg/m³Savoy, 14 July: no readingSavoy, 15 July: 11.1 µg/m³Savoy, 16 July: 54.5 µg/m³, 6.6× its usual 8.2Savoy, 17 July: 31.0 µg/m³, 3.8× its usual 8.2Savoy, 18 July: 11.7 µg/m³Savoy, 19 July: 11.6 µg/m³Savoy, 20 July: 10.4 µg/m³Savoy, 21 July: 6.3 µg/m³Savoy, 22 July: 7.9 µg/m³SpringfieldSpringfield, 11 July: 12.4 µg/m³Springfield, 12 July: 12.3 µg/m³Springfield, 13 July: 7.2 µg/m³Springfield, 14 July: 6.4 µg/m³Springfield, 15 July: 7.7 µg/m³Springfield, 16 July: 36.4 µg/m³, 3.5× its usual 10.3Springfield, 17 July: 53.3 µg/m³, 5.3× its usual 10.1Springfield, 18 July: 21.8 µg/m³Springfield, 19 July: 21.0 µg/m³Springfield, 20 July: 11.0 µg/m³Springfield, 21 July: 6.7 µg/m³Springfield, 22 July: 10.9 µg/m³Columbia CityColumbia City, 11 July: 9.3 µg/m³Columbia City, 12 July: 9.7 µg/m³Columbia City, 13 July: 4.4 µg/m³Columbia City, 14 July: no readingColumbia City, 15 July: 5.7 µg/m³Columbia City, 16 July: 52.5 µg/m³, 5.3× its usual 10.0Columbia City, 17 July: 51.0 µg/m³, 5.2× its usual 9.9Columbia City, 18 July: 9.5 µg/m³Columbia City, 19 July: 10.3 µg/m³Columbia City, 20 July: 12.7 µg/m³Columbia City, 21 July: 6.8 µg/m³Columbia City, 22 July: 10.6 µg/m³East ChicagoEast Chicago, 11 July: 8.1 µg/m³East Chicago, 12 July: 4.9 µg/m³East Chicago, 13 July: 5.7 µg/m³East Chicago, 14 July: 5.8 µg/m³East Chicago, 15 July: 13.8 µg/m³East Chicago, 16 July: 52.0 µg/m³, 5.7× its usual 9.1East Chicago, 17 July: 24.6 µg/m³East Chicago, 18 July: 6.6 µg/m³East Chicago, 19 July: 6.2 µg/m³East Chicago, 20 July: 11.3 µg/m³East Chicago, 21 July: 6.6 µg/m³East Chicago, 22 July: 11.3 µg/m³DublinDublin, 11 July: 10.7 µg/m³Dublin, 12 July: 10.9 µg/m³Dublin, 13 July: 6.3 µg/m³Dublin, 14 July: no readingDublin, 15 July: 6.9 µg/m³Dublin, 16 July: 25.1 µg/m³, 2.8× its usual 9.0Dublin, 17 July: 51.7 µg/m³, 5.7× its usual 9.0Dublin, 18 July: 21.0 µg/m³Dublin, 19 July: 17.1 µg/m³Dublin, 20 July: 9.0 µg/m³Dublin, 21 July: 5.7 µg/m³Dublin, 22 July: 9.0 µg/m³SpringfieldSpringfield, 11 July: 9.4 µg/m³Springfield, 12 July: 10.9 µg/m³Springfield, 13 July: 4.8 µg/m³Springfield, 14 July: 7.8 µg/m³Springfield, 15 July: 19.6 µg/m³Springfield, 16 July: 50.3 µg/m³, 5.5× its usual 9.2Springfield, 17 July: 21.9 µg/m³Springfield, 18 July: 14.1 µg/m³Springfield, 19 July: 12.6 µg/m³Springfield, 20 July: 11.1 µg/m³Springfield, 21 July: 8.1 µg/m³Springfield, 22 July: 8.7 µg/m³ErieErie, 11 July: 8.3 µg/m³Erie, 12 July: 7.0 µg/m³Erie, 13 July: 6.2 µg/m³Erie, 14 July: 6.3 µg/m³Erie, 15 July: 6.0 µg/m³Erie, 16 July: 22.3 µg/m³Erie, 17 July: 58.3 µg/m³, 7.6× its usual 7.7Erie, 18 July: 22.9 µg/m³Erie, 19 July: 6.5 µg/m³Erie, 20 July: 8.4 µg/m³Erie, 21 July: 5.9 µg/m³Erie, 22 July: 10.0 µg/m³MaconMacon, 11 July: 8.9 µg/m³Macon, 12 July: 11.3 µg/m³Macon, 13 July: 9.8 µg/m³Macon, 14 July: 9.2 µg/m³Macon, 15 July: 10.5 µg/m³Macon, 16 July: 8.6 µg/m³Macon, 17 July: 29.3 µg/m³, 3.1× its usual 9.6Macon, 18 July: 56.8 µg/m³, 6.0× its usual 9.5Macon, 19 July: 33.4 µg/m³, 3.6× its usual 9.4Macon, 20 July: 20.0 µg/m³Macon, 21 July: 14.7 µg/m³Macon, 22 July: 8.2 µg/m³Warner RobinsWarner Robins, 11 July: 8.2 µg/m³Warner Robins, 12 July: 10.3 µg/m³Warner Robins, 13 July: 8.7 µg/m³Warner Robins, 14 July: 8.2 µg/m³Warner Robins, 15 July: 10.4 µg/m³Warner Robins, 16 July: 8.1 µg/m³Warner Robins, 17 July: 27.8 µg/m³, 3.4× its usual 8.2Warner Robins, 18 July: 56.4 µg/m³, 6.9× its usual 8.2Warner Robins, 19 July: 33.8 µg/m³, 4.2× its usual 8.1Warner Robins, 20 July: 20.3 µg/m³Warner Robins, 21 July: 14.7 µg/m³Warner Robins, 22 July: 9.0 µg/m³McDonoughMcDonough, 11 July: 6.8 µg/m³McDonough, 12 July: 8.1 µg/m³McDonough, 13 July: 8.0 µg/m³McDonough, 14 July: no readingMcDonough, 15 July: 7.0 µg/m³McDonough, 16 July: 8.2 µg/m³McDonough, 17 July: 33.8 µg/m³, 4.6× its usual 7.3McDonough, 18 July: 55.8 µg/m³, 7.7× its usual 7.2McDonough, 19 July: 33.5 µg/m³, 4.9× its usual 6.8McDonough, 20 July: 15.8 µg/m³McDonough, 21 July: 9.4 µg/m³McDonough, 22 July: 5.0 µg/m³Beaver FallsBeaver Falls, 11 July: 11.9 µg/m³Beaver Falls, 12 July: 14.5 µg/m³Beaver Falls, 13 July: 11.8 µg/m³Beaver Falls, 14 July: no readingBeaver Falls, 15 July: 10.9 µg/m³Beaver Falls, 16 July: 12.6 µg/m³Beaver Falls, 17 July: 53.5 µg/m³, 5.4× its usual 9.9Beaver Falls, 18 July: 31.3 µg/m³, 3.2× its usual 9.9Beaver Falls, 19 July: 16.3 µg/m³Beaver Falls, 20 July: 12.3 µg/m³Beaver Falls, 21 July: 6.2 µg/m³Beaver Falls, 22 July: 10.1 µg/m³FairviewFairview, 11 July: 9.9 µg/m³Fairview, 12 July: 11.7 µg/m³Fairview, 13 July: 10.3 µg/m³Fairview, 14 July: no readingFairview, 15 July: 8.6 µg/m³Fairview, 16 July: 22.2 µg/m³Fairview, 17 July: 52.7 µg/m³, 5.5× its usual 9.6Fairview, 18 July: 37.3 µg/m³, 4.0× its usual 9.3Fairview, 19 July: 5.3 µg/m³Fairview, 20 July: 8.2 µg/m³Fairview, 21 July: 8.0 µg/m³Fairview, 22 July: 10.1 µg/m³East RidgeEast Ridge, 11 July: 9.9 µg/m³East Ridge, 12 July: 11.7 µg/m³East Ridge, 13 July: 10.3 µg/m³East Ridge, 14 July: 8.9 µg/m³East Ridge, 15 July: 8.6 µg/m³East Ridge, 16 July: 22.2 µg/m³East Ridge, 17 July: 52.7 µg/m³, 5.5× its usual 9.6East Ridge, 18 July: 37.3 µg/m³, 4.0× its usual 9.3East Ridge, 19 July: 5.3 µg/m³East Ridge, 20 July: 8.2 µg/m³East Ridge, 21 July: 8.0 µg/m³East Ridge, 22 July: 10.1 µg/m³Winston-SalemWinston-Salem, 11 July: 10.3 µg/m³Winston-Salem, 12 July: 12.9 µg/m³Winston-Salem, 13 July: 13.6 µg/m³Winston-Salem, 14 July: 6.4 µg/m³Winston-Salem, 15 July: 9.4 µg/m³Winston-Salem, 16 July: 8.4 µg/m³Winston-Salem, 17 July: 52.1 µg/m³, 5.9× its usual 8.8Winston-Salem, 18 July: 48.8 µg/m³, 5.5× its usual 8.8Winston-Salem, 19 July: 24.0 µg/m³Winston-Salem, 20 July: 7.5 µg/m³Winston-Salem, 21 July: 9.4 µg/m³Winston-Salem, 22 July: 10.3 µg/m³KnoxvilleKnoxville, 11 July: 10.3 µg/m³Knoxville, 12 July: 12.5 µg/m³Knoxville, 13 July: 12.1 µg/m³Knoxville, 14 July: 8.8 µg/m³Knoxville, 15 July: 9.7 µg/m³Knoxville, 16 July: 19.9 µg/m³Knoxville, 17 July: 51.7 µg/m³, 6.3× its usual 8.2Knoxville, 18 July: 41.4 µg/m³, 5.1× its usual 8.1Knoxville, 19 July: 5.1 µg/m³Knoxville, 20 July: 5.0 µg/m³Knoxville, 21 July: 7.9 µg/m³Knoxville, 22 July: 9.5 µg/m³SpartanburgSpartanburg, 11 July: 8.5 µg/m³Spartanburg, 12 July: 10.4 µg/m³Spartanburg, 13 July: 13.3 µg/m³Spartanburg, 14 July: 6.7 µg/m³Spartanburg, 15 July: 7.8 µg/m³Spartanburg, 16 July: 11.7 µg/m³Spartanburg, 17 July: 41.2 µg/m³, 4.3× its usual 9.6Spartanburg, 18 July: 50.7 µg/m³, 5.3× its usual 9.5Spartanburg, 19 July: 15.0 µg/m³Spartanburg, 20 July: 7.6 µg/m³Spartanburg, 21 July: 7.6 µg/m³Spartanburg, 22 July: 10.7 µg/m³GainesvilleGainesville, 11 July: 8.6 µg/m³Gainesville, 12 July: 12.2 µg/m³Gainesville, 13 July: 12.8 µg/m³Gainesville, 14 July: 10.0 µg/m³Gainesville, 15 July: 10.0 µg/m³Gainesville, 16 July: 17.7 µg/m³Gainesville, 17 July: 44.3 µg/m³, 4.8× its usual 9.2Gainesville, 18 July: 50.3 µg/m³, 5.5× its usual 9.1Gainesville, 19 July: 8.4 µg/m³Gainesville, 20 July: 12.7 µg/m³Gainesville, 21 July: 8.7 µg/m³Gainesville, 22 July: 9.9 µg/m³11 Jul1315171921
The 60 cities with the highest readings of 322, 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
Grande PrairieAlberta, Canada2 154.016 July6.623×
Williams LakeBritish Columbia, Canada1 112.015 July4.722×
Swift CurrentSaskatchewan, Canada2 159.015 July8.519×
Fort SaskatchewanAlberta, Canada2 180.015 July10.118×
PierreSouth Dakota, United States2 86.815 July4.717×
EdmontonAlberta, Canada2 202.015 July12.117×
HavreMontana, United States2 86.216 July5.316×
Fort St. JohnBritish Columbia, Canada2 90.816 July5.915×
VermillionSouth Dakota, United States2 76.116 July5.514×
Medicine HatAlberta, Canada2 92.016 July7.113×
St. AlbertAlberta, Canada2 112.015 July8.813×
Sioux FallsSouth Dakota, United States2 66.616 July5.612×
Miles CityMontana, United States2 86.316 July7.611×
Fort McMurrayAlberta, Canada1 144.515 July12.811×
BrookingsSouth Dakota, United States3 71.615 July6.711×
Red DeerAlberta, Canada2 91.915 July9.49.8×
MarshallMinnesota, United States2 75.815 July7.79.8×
Grand CentreAlberta, Canada1 99.215 July10.79.3×
KamloopsBritish Columbia, Canada1 76.215 July8.49.1×
BloomingtonIllinois, United States2 74.016 July8.48.8×
MuscatineIowa, United States3 53.216 July6.68.1×
Drayton ValleyAlberta, Canada2 60.815 July7.87.8×
LaconiaNew Hampshire, United States2 39.018 July5.07.8×
McDonoughGeorgia, United States3 55.818 July7.27.7×
AnkenyIowa, United States2 68.516 July9.07.6×
Des MoinesIowa, United States2 65.316 July8.67.6×
EriePennsylvania, United States1 58.317 July7.77.6×
AberdeenSouth Dakota, United States3 37.515 July5.07.5×
AthensGeorgia, United States2 49.918 July6.97.2×
Iowa CityIowa, United States3 62.416 July8.87.1×
MolineIllinois, United States3 60.916 July8.67.1×
BraidwoodIllinois, United States2 58.116 July8.27.1×
Warrensville HeightsOhio, United States2 59.017 July8.47.0×
PainesvilleOhio, United States2 48.517 July6.97.0×
MedinaOhio, United States2 60.417 July8.86.9×
DavenportIowa, United States3 59.016 July8.66.9×
Warner RobinsGeorgia, United States3 56.418 July8.26.9×
LethbridgeAlberta, Canada2 51.916 July7.66.8×
AkronOhio, United States2 56.217 July8.46.7×
GreenvilleSouth Carolina, United States2 46.418 July6.96.7×
Rapid CitySouth Dakota, United States2 55.416 July8.46.6×
SavoyIllinois, United States2 54.516 July8.26.6×
HermitagePennsylvania, United States1 50.217 July7.96.4×
MiddlesboroKentucky, United States1 48.917 July7.76.4×
KnoxvilleTennessee, United States2 51.717 July8.26.3×
WatertownSouth Dakota, United States3 49.515 July7.86.3×
HuntsvilleAlabama, United States2 48.617 July7.76.3×
YoungstownOhio, United States2 58.017 July9.56.1×
WaterlooIowa, United States2 48.416 July8.06.1×
LawrencevilleGeorgia, United States2 46.718 July7.66.1×
GilletteWyoming, United States2 35.715 July5.96.1×
MaconGeorgia, United States3 56.818 July9.56.0×
DecaturIllinois, United States2 56.016 July9.36.0×
SyracuseNew York, United States2 42.117 July7.06.0×
Winston-SalemNorth Carolina, United States2 52.117 July8.85.9×
RochesterNew York, United States2 49.217 July8.35.9×
Apple ValleyMinnesota, United States1 48.015 July8.25.9×
AlbanyGeorgia, United States2 46.718 July7.95.9×
BurlingtonVermont, United States2 41.918 July7.15.9×
HazardKentucky, United States1 40.617 July6.95.9×
DentsvilleSouth Carolina, United States1 40.618 July6.95.9×
WarrenOhio, United States3 63.617 July11.05.8×
East ChicagoIndiana, United States1 52.016 July9.15.7×
DublinOhio, United States2 51.717 July9.05.7×
GahannaOhio, United States1 45.617 July8.05.7×
New AlbanyOhio, United States1 45.617 July8.05.7×
CantonOhio, United States2 61.017 July10.95.6×
Candler-McAfeeGeorgia, United States2 49.018 July8.75.6×
ClemmonsNorth Carolina, United States2 45.717 July8.15.6×
AirdrieAlberta, Canada2 41.116 July7.35.6×
GreenfieldMassachusetts, United States2 38.717 July6.95.6×
LoudonTennessee, United States2 37.517 July6.75.6×
JolietIllinois, United States2 57.516 July10.45.5×
BurnsvilleMinnesota, United States1 52.715 July9.65.5×
FairviewGeorgia, United States2 52.717 July9.65.5×
East RidgeTennessee, United States2 52.717 July9.65.5×
SpringfieldIllinois, United States1 50.316 July9.25.5×
GainesvilleGeorgia, United States2 50.318 July9.15.5×
ChattanoogaTennessee, United States2 49.217 July9.05.5×
AndersonIndiana, United States2 47.817 July8.75.5×
DurhamNorth Carolina, United States2 36.818 July6.75.5×
BenningtonVermont, United States2 36.717 July6.75.5×
CranbrookBritish Columbia, Canada1 34.715 July6.35.5×
ClevelandOhio, United States2 61.317 July11.35.4×
Beaver FallsPennsylvania, United States2 53.517 July9.95.4×
AltoonaWisconsin, United States1 47.115 July8.75.4×
Eau ClaireWisconsin, United States1 47.115 July8.75.4×
New BrightonPennsylvania, United States2 46.017 July8.55.4×
CharlotteNorth Carolina, United States2 45.818 July8.55.4×
MaryvilleTennessee, United States2 41.817 July7.75.4×
RoanokeVirginia, United States1 41.717 July7.75.4×
Weirton HeightsWest Virginia, United States1 41.317 July7.75.4×
BlairNebraska, United States2 37.116 July6.95.4×
WestervilleOhio, United States2 59.217 July11.15.3×
Calumet CityIllinois, United States2 55.816 July10.55.3×
SpringfieldOhio, United States2 53.317 July10.15.3×
Columbia CityIndiana, United States2 52.516 July10.05.3×
SpartanburgSouth Carolina, United States2 50.718 July9.55.3×
ShakopeeMinnesota, United States1 50.615 July9.65.3×
FayettevilleNorth Carolina, United States2 47.918 July9.15.3×
RaleighNorth Carolina, United States2 45.618 July8.65.3×
LewistownMontana, United States2 43.215 July8.15.3×
DentOhio, United States1 39.016 July7.35.3×
White OakOhio, United States1 39.016 July7.35.3×
HarrimanTennessee, United States2 37.617 July7.15.3×
KeeneNew Hampshire, United States2 37.517 July7.15.3×
VernonBritish Columbia, Canada1 33.115 July6.35.3×
Mount IvyNew York, United States2 31.417 July5.95.3×
New CityNew York, United States2 31.417 July5.95.3×
HickoryNorth Carolina, United States2 43.018 July8.35.2×
GreenvilleNorth Carolina, United States1 42.918 July8.35.2×
SavannahGeorgia, United States2 38.119 July7.35.2×
BillingsMontana, United States2 37.615 July7.25.2×
LockwoodMontana, United States2 37.615 July7.25.2×
HartfordVermont, United States2 37.018 July7.15.2×
Phenix CityAlabama, United States2 39.518 July7.75.1×
UticaNew York, United States2 36.317 July7.15.1×
PikevilleKentucky, United States1 35.517 July6.95.1×
DaytonOhio, United States2 49.317 July9.95.0×
BuffaloNew York, United States2 47.817 July9.65.0×
LafayetteIndiana, United States1 46.216 July9.35.0×
BloomingtonIndiana, United States2 40.616 July8.25.0×
FairfieldAlabama, United States2 40.417 July8.15.0×
HueytownAlabama, United States2 40.417 July8.15.0×
AthensTennessee, United States2 39.817 July7.95.0×
AshlandKentucky, United States1 39.417 July7.95.0×
SomersetKentucky, United States2 37.717 July7.55.0×
North AdamsMassachusetts, United States2 37.717 July7.55.0×
KingsportTennessee, United States2 36.917 July7.45.0×
HaverhillMassachusetts, United States1 33.717 July6.85.0×
CalgaryAlberta, Canada2 49.915 July10.14.9×
MorrisvilleNorth Carolina, United States2 44.518 July9.14.9×
LexingtonNorth Carolina, United States2 43.018 July8.74.9×
ClaytonNorth Carolina, United States2 41.018 July8.44.9×
PaducahKentucky, United States1 39.816 July8.24.9×
CharlottesvilleVirginia, United States2 39.817 July8.14.9×
ElizabethtownKentucky, United States2 37.116 July7.64.9×
AshevilleNorth Carolina, United States2 34.418 July7.04.9×
North ChicopeeMassachusetts, United States1 30.817 July6.34.9×
NewburghNew York, United States2 29.317 July6.04.9×
HammondIndiana, United States2 49.416 July10.34.8×
PittsburghPennsylvania, United States2 47.617 July10.04.8×
Des PlainesIllinois, United States1 45.616 July9.64.8×
AtlantaGeorgia, United States2 43.518 July9.14.8×
RutlandVermont, United States2 39.618 July8.24.8×
JerseyvilleIllinois, United States1 38.216 July7.94.8×
PittsfieldMassachusetts, United States2 37.018 July7.74.8×
LebanonOhio, United States2 36.617 July7.74.8×
LeedsAlabama, United States2 36.117 July7.54.8×
TrussvilleAlabama, United States2 36.117 July7.54.8×
BethlehemPennsylvania, United States2 33.517 July7.04.8×
BellevueNebraska, United States2 30.615 July6.44.8×
LimaOhio, United States2 47.917 July10.14.7×
LouisvilleKentucky, United States2 44.316 July9.54.7×
JeffersontownKentucky, United States2 41.516 July8.94.7×
GreensboroNorth Carolina, United States2 40.818 July8.64.7×
St. CatharinesOntario, Canada2 40.317 July8.54.7×
Rose HillVirginia, United States2 37.917 July8.04.7×
ValdostaGeorgia, United States2 37.419 July7.94.7×
WareMassachusetts, United States1 31.217 July6.64.7×
KenmoreNew York, United States2 43.117 July9.44.6×
KokomoIndiana, United States1 42.216 July9.14.6×
JeffersonvilleIndiana, United States2 41.116 July8.94.6×
Saint MichaelMinnesota, United States1 39.615 July8.74.6×
ColumbiaTennessee, United States2 34.617 July7.54.6×
Lexington-FayetteKentucky, United States2 33.317 July7.24.6×
GaryIndiana, United States1 45.216 July10.14.5×
RockfordIllinois, United States2 44.016 July9.74.5×
BirminghamAlabama, United States2 42.617 July9.44.5×
OwensboroKentucky, United States2 41.616 July9.34.5×
MonessenPennsylvania, United States2 40.817 July9.04.5×
Saint CloudMinnesota, United States2 37.015 July8.34.5×
Oak GroveKentucky, United States2 34.516 July7.74.5×
ClarksvilleTennessee, United States2 34.516 July7.74.5×
LowellMassachusetts, United States1 31.317 July7.04.5×
BrunswickGeorgia, United States2 30.019 July6.64.5×
RochesterMinnesota, United States2 45.815 July10.44.4×
Saint MatthewsKentucky, United States2 37.816 July8.64.4×
St. ThomasOntario, Canada1 37.517 July8.64.4×
EdgewoodMaryland, United States2 32.718 July7.54.4×
HagerstownMaryland, United States1 25.317 July5.84.4×
HalfwayMaryland, United States1 25.317 July5.84.4×
SteubenvilleOhio, United States1 43.817 July10.34.3×
Kennedy TownshipPennsylvania, United States2 43.417 July10.04.3×
Saint PaulMinnesota, United States1 43.215 July10.14.3×
NorthbrookIllinois, United States1 42.616 July9.94.3×
CaryIllinois, United States1 40.616 July9.54.3×
Saint AndrewsSouth Carolina, United States1 38.218 July8.94.3×
SandersvilleGeorgia, United States3 36.918 July8.64.3×
State CollegePennsylvania, United States2 31.317 July7.34.3×
BarabooWisconsin, United States2 30.216 July7.04.3×
Franklin ParkIllinois, United States1 48.316 July11.64.2×
NapervilleIllinois, United States1 47.916 July11.34.2×
Terre HauteIndiana, United States1 41.616 July10.04.2×
WilkinsburgPennsylvania, United States1 41.117 July9.74.2×
FlorenceSouth Carolina, United States2 37.718 July9.04.2×
LancasterPennsylvania, United States2 36.917 July8.84.2×
MadisonWisconsin, United States2 34.916 July8.44.2×
NewarkDelaware, United States2 33.118 July7.94.2×
Fort ThomasKentucky, United States2 33.016 July7.94.2×
Highland HeightsKentucky, United States2 33.016 July7.94.2×
Kennett SquarePennsylvania, United States2 32.818 July7.84.2×
BaltimoreMaryland, United States2 32.717 July7.74.2×
Hunt ValleyMaryland, United States2 28.517 July6.84.2×
IndianapolisIndiana, United States2 44.316 July10.74.1×
FlatwoodsKentucky, United States1 42.917 July10.54.1×
SpringfieldVirginia, United States2 34.117 July8.44.1×
AllentownPennsylvania, United States1 31.717 July7.74.1×
FrostburgMaryland, United States1 30.217 July7.44.1×
CastlegarBritish Columbia, Canada1 30.015 July7.44.1×
DerryNew Hampshire, United States1 29.217 July7.14.1×
LondonderryNew Hampshire, United States1 29.217 July7.14.1×
WorcesterMassachusetts, United States1 28.717 July7.04.1×
TecumsehMichigan, United States2 37.816 July9.54.0×
Valley StationKentucky, United States2 36.716 July9.14.0×
WheelingWest Virginia, United States1 34.617 July8.74.0×
OmahaNebraska, United States2 32.816 July8.24.0×
PortageIndiana, United States1 39.316 July10.03.9×
South BendIndiana, United States2 38.616 July9.93.9×
West FargoNorth Dakota, United States2 37.014 July9.53.9×
OakvilleOntario, Canada1 34.517 July8.93.9×
WaterdownOntario, Canada1 34.317 July8.73.9×
AppletonWisconsin, United States2 33.616 July8.63.9×
AltoonaPennsylvania, United States2 33.017 July8.53.9×
KingstonOntario, Canada2 31.517 July8.13.9×
YorkPennsylvania, United States2 31.217 July7.93.9×
South LaurelMaryland, United States1 30.317 July7.83.9×
SherbrookeQuebec, Canada2 29.918 July7.63.9×
BellevilleOntario, Canada1 29.717 July7.73.9×
CookevilleTennessee, United States1 28.317 July7.33.9×
EstevanSaskatchewan, Canada1 46.815 July12.43.8×
MoundsvilleWest Virginia, United States1 36.617 July9.63.8×
Jefferson HillsPennsylvania, United States1 35.917 July9.43.8×
McKeesportPennsylvania, United States1 35.917 July9.43.8×
HamiltonOntario, Canada1 34.917 July9.33.8×
New HollandPennsylvania, United States2 33.917 July9.03.8×
GranbyQuebec, Canada1 33.218 July8.83.8×
DrummondvilleQuebec, Canada1 31.918 July8.33.8×
North CharlestonSouth Carolina, United States1 31.419 July8.33.8×
PeterboroughOntario, Canada1 30.017 July8.03.8×
SpringfieldMassachusetts, United States1 29.617 July7.83.8×
NorristownPennsylvania, United States2 28.718 July7.53.8×
EdmundstonNew Brunswick, Canada1 27.618 July7.33.8×
Saint-Jean-sur-RichelieuQuebec, Canada1 27.018 July7.13.8×
SaskatoonSaskatchewan, Canada1 46.315 July12.63.7×
Great FallsMontana, United States2 44.815 July12.13.7×
BrantfordOntario, Canada1 33.417 July9.13.7×
ChathamOntario, Canada1 28.817 July7.73.7×
ReadingPennsylvania, United States1 28.517 July7.83.7×
WyomissingPennsylvania, United States1 28.517 July7.83.7×
AugustaGeorgia, United States1 26.818 July7.33.7×
LynnMassachusetts, United States1 25.617 July6.93.7×
CheektowagaNew York, United States2 47.317 July13.03.6×
FishersIndiana, United States2 37.416 July10.33.6×
McCordsvilleIndiana, United States2 37.416 July10.33.6×
AlbanyNew York, United States2 35.018 July9.63.6×
TarboroNorth Carolina, United States1 31.918 July8.83.6×
CarlislePennsylvania, United States2 28.117 July7.73.6×
SchlusserPennsylvania, United States2 28.117 July7.73.6×
SaguenayQuebec, Canada1 31.718 July9.03.5×
MississaugaOntario, Canada1 27.317 July7.93.5×
WilmingtonDelaware, United States1 27.118 July7.73.5×
GlasgowDelaware, United States1 25.418 July7.33.5×
ElktonMaryland, United States1 25.418 July7.33.5×
LincolnNebraska, United States1 25.015 July7.13.5×
West MifflinPennsylvania, United States1 38.717 July11.53.4×
La CrosseWisconsin, United States2 34.415 July10.23.4×
WashingtonDistrict of Columbia, United States1 32.217 July9.43.4×
QuébecQuebec, Canada1 30.818 July9.13.4×
MontréalQuebec, Canada1 29.518 July8.83.4×
BlaineMinnesota, United States1 29.315 July8.53.4×
GreendaleWisconsin, United States2 29.116 July8.53.4×
South MilwaukeeWisconsin, United States2 29.116 July8.53.4×
University CityMissouri, United States1 26.916 July8.03.4×
BostonMassachusetts, United States1 26.317 July7.73.4×
MiddletownOhio, United States2 39.817 July11.93.3×
NorwoodOhio, United States2 38.016 July11.43.3×
L'Ancienne-LoretteQuebec, Canada2 34.218 July10.43.3×
East Saint LouisIllinois, United States1 33.116 July10.13.3×
ChicagoIllinois, United States1 32.416 July9.83.3×
BrossardQuebec, Canada1 31.718 July9.53.3×
HarrisburgPennsylvania, United States2 31.417 July9.43.3×
WaukeshaWisconsin, United States2 31.115 July9.33.3×
LebanonPennsylvania, United States2 29.817 July9.03.3×
PortlandMaine, United States1 28.718 July8.73.3×
ArnoldMissouri, United States1 26.116 July8.03.3×
ScrantonPennsylvania, United States2 28.417 July9.03.2×
HendersonvilleTennessee, United States2 27.117 July8.53.2×
Columbia FallsMontana, United States1 25.515 July7.93.2×
CincinnatiOhio, United States2 35.616 July11.63.1×
MilwaukeeWisconsin, United States2 31.715 July10.23.1×
ElkhartIndiana, United States2 31.216 July10.13.1×
ScaggsvilleMaryland, United States2 29.817 July9.63.1×
Green BayWisconsin, United States2 29.615 July9.53.1×
HollandMichigan, United States1 29.516 July9.53.1×
LondonOntario, Canada1 27.917 July9.13.1×
PatersonNew Jersey, United States1 26.918 July8.73.1×
Lake CityFlorida, United States1 26.618 July8.53.1×
CornwallOntario, Canada1 26.518 July8.63.1×
JohnstownPennsylvania, United States1 26.117 July8.53.1×
BramptonOntario, Canada1 26.017 July8.53.1×
ToledoOhio, United States2 33.217 July11.03.0×
Oak LawnIllinois, United States1 31.416 July10.33.0×
MiltonOntario, Canada1 30.017 July10.03.0×
ShawiniganQuebec, Canada1 28.218 July9.43.0×
Trois-RivièresQuebec, Canada1 27.318 July9.13.0×
Granite CityIllinois, United States1 29.616 July10.32.9×
St. LouisMissouri, United States1 28.916 July10.12.9×
TorontoOntario, Canada1 28.717 July9.82.9×
BensalemPennsylvania, United States2 26.417 July9.02.9×
ReginaSaskatchewan, Canada1 32.915 July11.82.8×
Lincoln ParkMichigan, United States2 28.716 July10.12.8×
JacksonTennessee, United States2 27.016 July9.72.8×
YpsilantiMichigan, United States1 25.216 July9.02.8×
PhiladelphiaPennsylvania, United States1 26.818 July10.12.7×
WindsorOntario, Canada1 26.417 July10.32.6×
DuluthMinnesota, United States1 25.914 July9.92.6×
DearbornMichigan, United States2 28.116 July11.32.5×
DetroitMichigan, United States2 27.617 July10.92.5×
KalamazooMichigan, United States1 27.216 July11.42.4×
SuperiorWisconsin, United States1 25.414 July10.82.4×
LexingtonMassachusetts, United States1 27.918 July12.02.3×

Daily means in µg/m³, over the days each city counted in this episode. Highest: its highest of those days. Usual: the city's median for the time of year of that day (its days within 21 days of the date, every year, leaving out the week around it). Above usual: its highest day against that, with a usual under 5 µg/m³ taken as 5.

Against other episodes in the United States and Canada

Number 3 of 173 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 173.

Use this page

SmogRank, United States and Canada, July 2023: 322 cities with PM2.5 at twice their usual or more, 14 to 19 July 2023, smogrank.com/episodes/2023-07-united-states-and-canada (accessed 5 October 2026).

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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. Fire detections from NASA FIRMS; smoke maps from NOAA HMS.