SmogRank / Episodes / United States

North-eastern United States and Canada, June 2025

For 7 days, from 3 to 9 June 2025, 196 cities in the United States and Canada had PM2.5 at least twice their usual for the time of year. The worst reading was Nepean, Ontario, Canada: 116.0 µg/m³ on 6 June, about 16× its usual 7.4.

No cause namedWe have no fire or smoke records for these days, so we only say what the measurements show.
Cities reached196in 2 countries
Days73 to 9 June 2025
Worst day7 June115 cities counted
Furthest above usual19×Marquette

Day by day

7 June 115 cities at twice their usual or more
Ann ArborMcKeesportJohnstownLebanonMasonWhite OakFort ThomasCharlestonFishersHagerstownCarlisleIndianapolisHarrisburgColumbusHarrisonburgLexington-FayetteYorkLebanonAshburnNicholasvilleBloomingtonRockvilleLancasterCharlottesvilleJeffersontownSaint MatthewsJeffersonvilleHunt ValleyNew AlbanyScaggsvilleRoanokeSpringfieldReadingWashingtonSouth LaurelRose HillBaltimoreValley StationOxon Hill-GlassmanorEssexTerre HauteEdgewoodAllentownBethlehemKingsportElizabethtownElktonNewarkJasperBearNorristownShort PumpWilmingtonChesterRichmondPhiladelphiaPennsaukenBensalemSewellRandolphDoverEwingTrentonHopewellOwensboroSouth VinelandNew BrunswickNewburghEvansvillePatersonLindenElizabethNew CityBayonneJersey CityFort LeeNew York CityWhite PlainsPleasantvilleToms RiverAtlantic CityPittsfieldDanburyEast HamptonChesapeakeBridgeportWaterburyClarksvilleNew HavenHolbrookHartfordPaducahUniversity CityLemayNew LondonArnoldLaconiaCoventryProvidencePawtucketFall RiverBrocktonLewistonBangorSpringfieldLibertyRaymoreKansas CitySaint JosephLeawoodBellevueOmahaLa VistaSioux FallsBrookingsLincolnWatertownFrederictonWest FargoSaint JohnMiramichiAberdeenGrand IslandPonca CityMonctonSt. LouisMiddletownWest MifflinNorwoodGranite CityCincinnatiLouisvilleElkhartAnkenySpringfieldDaytonWheelingClevelandScrantonEast Saint LouisLimaWyomingWichitaPittsburghDes MoinesKokomoAndersonSteubenvilleAshlandSpringfieldColumbiaMuscatineWilkinsburgKansas CityDublinWaterlooDerbyWeirton HeightsDecaturFlintColumbusBuffaloWestervilleLafayetteClintonAugustaHuntingtonOlatheMedinaMuncieCleveland HeightsBay CityRockfordTopekaState CollegeCantonMilfordErieAkronFort WayneUpper AltonSpringfieldBarrieHollandGahannaKeenePortlandGreenfieldBrookfieldWorcesterNorth ChicopeeWeirtonAlbanyRedfordSouth BendDavenportShaker HeightsPainesvilleDerryWarrenGaryPortsmouthPortsmouthFraminghamChampaignToledoBostonRutlandMolineUticaLowellSt. CatharinesKalamazooGrand RapidsHermitageYoungstownPerrysburgJenisonPeoriaWaukeshaMilwaukeePortageQuincyAltoonaLynnHaverhillOregonIowa CityNapervilleJolietSouth MilwaukeeLansingCaryDearbornDrummondvilleOak LawnSherbrookeNorth BayDetroitBloomingtonNorthbrookSt. ThomasCalumet CityBridgeviewSyracuseHamiltonGreater SudburyFranklin ParkMarquetteAllistonEast ChicagoRochesterChathamLincoln ParkChicagoHammondDes PlainesGranbyTaylorZionDoltonBrantfordSorel-TracySaint-Jean-sur-RichelieuYpsilantiAuroraWaterdownKitchenerPort HuronNewmarketElginMichigan CityCedar RapidsRochesterTrois-RivièresBrossardRouyn-NorandaSarniaMadisonLondonEastpointeEdmundstonShawiniganElmwood ParkTorontoBramptonSaint CloudGuelphSault Ste. MarieMississaugaOakvilleWindsorRivière-des-Prairies–Pointe-aux-TremblesMiltonSouthfieldMontréalSaguenayAppletonDorvalGreen BayQuébecKingstonEau ClaireL'Ancienne-LorettePeterboroughCornwallBurnsvilleSaint PaulApple ValleyShakopeeMinneapolisOconomowocBellevilleSaint MichaelMankatoSept-ÎlesNepeanSuperiorOttawaBlaineDuluth
31 May1 Jun23456789101112
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

MarquetteMarquette, 31 May: 4.6 µg/m³, 0.9× usualMarquette, 1 June: 2.8 µg/m³, 0.6× usualMarquette, 2 June: 16.3 µg/m³, 3.3× usualMarquette, 3 June: 98.2 µg/m³, 20× usualMarquette, 4 June: 36.9 µg/m³, 7.4× usualMarquette, 5 June: 19.0 µg/m³, 3.8× usualMarquette, 6 June: 17.5 µg/m³, 3.5× usualMarquette, 7 June: 22.4 µg/m³, 4.5× usualMarquette, 8 June: 23.4 µg/m³, 4.7× usualMarquette, 9 June: 14.2 µg/m³, 2.8× usualMarquette, 10 June: 11.3 µg/m³, 2.3× usualMarquette, 11 June: 24.7 µg/m³, 4.9× usualMarquette, 12 June: 6.1 µg/m³, 1.2× usualDuluthDuluth, 31 May: 12.8 µg/m³, 2.6× usualDuluth, 1 June: 8.0 µg/m³, 1.6× usualDuluth, 2 June: 17.0 µg/m³, 3.4× usualDuluth, 3 June: 96.0 µg/m³, 19× usualDuluth, 4 June: 19.1 µg/m³, 3.8× usualDuluth, 5 June: 16.0 µg/m³, 3.2× usualDuluth, 6 June: 14.6 µg/m³, 2.9× usualDuluth, 7 June: 24.2 µg/m³, 4.8× usualDuluth, 8 June: 36.4 µg/m³, 7.3× usualDuluth, 9 June: 14.7 µg/m³, 2.9× usualDuluth, 10 June: 30.6 µg/m³, 6.1× usualDuluth, 11 June: 51.3 µg/m³, 10× usualDuluth, 12 June: 6.9 µg/m³, 1.4× usualBlaineBlaine, 31 May: 14.0 µg/m³, 2.7× usualBlaine, 1 June: 18.1 µg/m³, 3.5× usualBlaine, 2 June: 12.7 µg/m³, 2.4× usualBlaine, 3 June: 90.5 µg/m³, 17× usualBlaine, 4 June: 25.6 µg/m³, 4.9× usualBlaine, 5 June: 14.9 µg/m³, 2.9× usualBlaine, 6 June: 9.8 µg/m³, 1.9× usualBlaine, 7 June: 15.8 µg/m³, 3.0× usualBlaine, 8 June: 15.2 µg/m³, 2.9× usualBlaine, 9 June: 12.3 µg/m³, 2.4× usualBlaine, 10 June: 30.6 µg/m³, 5.9× usualBlaine, 11 June: 32.7 µg/m³, 6.3× usualBlaine, 12 June: 40.3 µg/m³, 7.7× usualMinneapolisMinneapolis, 31 May: 15.8 µg/m³, 2.5× usualMinneapolis, 1 June: 20.2 µg/m³, 3.2× usualMinneapolis, 2 June: 13.7 µg/m³, 2.1× usualMinneapolis, 3 June: 90.2 µg/m³, 14× usualMinneapolis, 4 June: 28.9 µg/m³, 4.5× usualMinneapolis, 5 June: 17.7 µg/m³, 2.8× usualMinneapolis, 6 June: 11.8 µg/m³, 1.8× usualMinneapolis, 7 June: 18.3 µg/m³, 2.9× usualMinneapolis, 8 June: 16.3 µg/m³, 2.5× usualMinneapolis, 9 June: 13.0 µg/m³, 2.0× usualMinneapolis, 10 June: 31.1 µg/m³, 4.9× usualMinneapolis, 11 June: 34.3 µg/m³, 5.4× usualMinneapolis, 12 June: 43.7 µg/m³, 6.8× usualSuperiorSuperior, 31 May: 20.2 µg/m³, 3.7× usualSuperior, 1 June: 8.2 µg/m³, 1.5× usualSuperior, 2 June: 11.9 µg/m³, 2.2× usualSuperior, 3 June: 88.7 µg/m³, 16× usualSuperior, 4 June: 19.2 µg/m³, 3.5× usualSuperior, 5 June: 13.4 µg/m³, 2.4× usualSuperior, 6 June: 12.2 µg/m³, 2.2× usualSuperior, 7 June: 18.9 µg/m³, 3.4× usualSuperior, 8 June: 27.9 µg/m³, 5.1× usualSuperior, 9 June: 11.2 µg/m³, 2.0× usualSuperior, 10 June: 24.7 µg/m³, 4.5× usualSuperior, 11 June: 40.6 µg/m³, 7.4× usualSuperior, 12 June: 6.6 µg/m³, 1.2× usualMankatoMankato, 31 May: 14.3 µg/m³, 2.5× usualMankato, 1 June: 21.0 µg/m³, 3.7× usualMankato, 2 June: 11.3 µg/m³, 2.0× usualMankato, 3 June: 85.0 µg/m³, 15× usualMankato, 4 June: 21.8 µg/m³, 3.8× usualMankato, 5 June: 14.4 µg/m³, 2.5× usualMankato, 6 June: 16.1 µg/m³, 2.8× usualMankato, 7 June: 18.7 µg/m³, 3.3× usualMankato, 8 June: 16.2 µg/m³, 2.8× usualMankato, 9 June: 12.9 µg/m³, 2.3× usualMankato, 10 June: 23.5 µg/m³, 4.1× usualMankato, 11 June: 35.8 µg/m³, 6.3× usualMankato, 12 June: 40.6 µg/m³, 7.1× usualShakopeeShakopee, 31 May: 14.1 µg/m³, 2.4× usualShakopee, 1 June: 24.2 µg/m³, 4.0× usualShakopee, 2 June: 11.3 µg/m³, 1.9× usualShakopee, 3 June: 84.2 µg/m³, 14× usualShakopee, 4 June: 24.7 µg/m³, 4.1× usualShakopee, 5 June: 13.5 µg/m³, 2.3× usualShakopee, 6 June: 11.3 µg/m³, 1.9× usualShakopee, 7 June: 17.0 µg/m³, 2.8× usualShakopee, 8 June: 15.2 µg/m³, 2.5× usualShakopee, 9 June: 11.4 µg/m³, 1.9× usualShakopee, 10 June: 27.4 µg/m³, 4.6× usualShakopee, 11 June: 33.5 µg/m³, 5.6× usualShakopee, 12 June: 43.8 µg/m³, 7.3× usualSaint MichaelSaint Michael, 31 May: 13.6 µg/m³, 2.4× usualSaint Michael, 1 June: 23.2 µg/m³, 4.1× usualSaint Michael, 2 June: 12.5 µg/m³, 2.2× usualSaint Michael, 3 June: 81.2 µg/m³, 15× usualSaint Michael, 4 June: 19.0 µg/m³, 3.4× usualSaint Michael, 5 June: 12.7 µg/m³, 2.3× usualSaint Michael, 6 June: 10.0 µg/m³, 1.8× usualSaint Michael, 7 June: 13.5 µg/m³, 2.4× usualSaint Michael, 8 June: 13.3 µg/m³, 2.4× usualSaint Michael, 9 June: 12.3 µg/m³, 2.2× usualSaint Michael, 10 June: 28.9 µg/m³, 5.2× usualSaint Michael, 11 June: 27.4 µg/m³, 4.9× usualSaint Michael, 12 June: 39.4 µg/m³, 7.0× usualSaint PaulSaint Paul, 31 May: 14.8 µg/m³, 2.4× usualSaint Paul, 1 June: 16.4 µg/m³, 2.7× usualSaint Paul, 2 June: 12.3 µg/m³, 2.0× usualSaint Paul, 3 June: 80.9 µg/m³, 13× usualSaint Paul, 4 June: 28.9 µg/m³, 4.7× usualSaint Paul, 5 June: 16.3 µg/m³, 2.7× usualSaint Paul, 6 June: 10.8 µg/m³, 1.8× usualSaint Paul, 7 June: 18.5 µg/m³, 3.0× usualSaint Paul, 8 June: 15.4 µg/m³, 2.5× usualSaint Paul, 9 June: 11.2 µg/m³, 1.8× usualSaint Paul, 10 June: 28.7 µg/m³, 4.7× usualSaint Paul, 11 June: 31.3 µg/m³, 5.1× usualSaint Paul, 12 June: 38.4 µg/m³, 6.3× usualBurnsvilleBurnsville, 31 May: 14.1 µg/m³, 2.2× usualBurnsville, 1 June: 20.8 µg/m³, 3.3× usualBurnsville, 2 June: 11.4 µg/m³, 1.8× usualBurnsville, 3 June: 79.7 µg/m³, 12× usualBurnsville, 4 June: 23.9 µg/m³, 3.7× usualBurnsville, 5 June: 12.9 µg/m³, 2.0× usualBurnsville, 6 June: 12.8 µg/m³, 2.0× usualBurnsville, 7 June: 20.4 µg/m³, 3.2× usualBurnsville, 8 June: 16.3 µg/m³, 2.5× usualBurnsville, 9 June: 11.1 µg/m³, 1.7× usualBurnsville, 10 June: 27.6 µg/m³, 4.3× usualBurnsville, 11 June: 35.2 µg/m³, 5.5× usualBurnsville, 12 June: 44.8 µg/m³, 7.0× usualApple ValleyApple Valley, 31 May: 13.9 µg/m³, 2.4× usualApple Valley, 1 June: 20.0 µg/m³, 3.5× usualApple Valley, 2 June: 11.8 µg/m³, 2.1× usualApple Valley, 3 June: 78.3 µg/m³, 14× usualApple Valley, 4 June: 25.7 µg/m³, 4.5× usualApple Valley, 5 June: 13.1 µg/m³, 2.3× usualApple Valley, 6 June: 14.1 µg/m³, 2.5× usualApple Valley, 7 June: 20.0 µg/m³, 3.5× usualApple Valley, 8 June: 16.9 µg/m³, 3.0× usualApple Valley, 9 June: 12.0 µg/m³, 2.1× usualApple Valley, 10 June: 27.2 µg/m³, 4.8× usualApple Valley, 11 June: 35.3 µg/m³, 6.2× usualApple Valley, 12 June: 46.1 µg/m³, 8.1× usualEau ClaireEau Claire, 31 May: 11.7 µg/m³, 2.1× usualEau Claire, 1 June: 8.1 µg/m³, 1.5× usualEau Claire, 2 June: 14.7 µg/m³, 2.7× usualEau Claire, 3 June: 63.2 µg/m³, 11× usualEau Claire, 4 June: 40.5 µg/m³, 7.4× usualEau Claire, 5 June: 14.0 µg/m³, 2.5× usualEau Claire, 6 June: 14.3 µg/m³, 2.6× usualEau Claire, 7 June: 19.5 µg/m³, 3.5× usualEau Claire, 8 June: 22.5 µg/m³, 4.1× usualEau Claire, 9 June: 9.6 µg/m³, 1.7× usualEau Claire, 10 June: 30.8 µg/m³, 5.6× usualEau Claire, 11 June: 34.8 µg/m³, 6.3× usualEau Claire, 12 June: 41.5 µg/m³, 7.5× usualRochesterRochester, 31 May: 16.5 µg/m³, 2.4× usualRochester, 1 June: 18.3 µg/m³, 2.6× usualRochester, 2 June: 13.9 µg/m³, 2.0× usualRochester, 3 June: 61.9 µg/m³, 8.8× usualRochester, 4 June: 36.7 µg/m³, 5.2× usualRochester, 5 June: 14.8 µg/m³, 2.1× usualRochester, 6 June: 16.3 µg/m³, 2.3× usualRochester, 7 June: 25.0 µg/m³, 3.6× usualRochester, 8 June: 21.6 µg/m³, 3.1× usualRochester, 9 June: 10.5 µg/m³, 1.5× usualRochester, 10 June: 25.3 µg/m³, 3.6× usualRochester, 11 June: 34.2 µg/m³, 4.9× usualRochester, 12 June: 42.0 µg/m³, 6.0× usualSaint CloudSaint Cloud, 31 May: 13.7 µg/m³, 2.5× usualSaint Cloud, 1 June: 22.0 µg/m³, 4.0× usualSaint Cloud, 2 June: 14.3 µg/m³, 2.6× usualSaint Cloud, 3 June: 54.7 µg/m³, 9.9× usualSaint Cloud, 4 June: 13.5 µg/m³, 2.5× usualSaint Cloud, 5 June: 11.3 µg/m³, 2.1× usualSaint Cloud, 6 June: 8.5 µg/m³, 1.5× usualSaint Cloud, 7 June: 9.7 µg/m³, 1.8× usualSaint Cloud, 8 June: 11.2 µg/m³, 2.0× usualSaint Cloud, 9 June: 12.5 µg/m³, 2.3× usualSaint Cloud, 10 June: 26.4 µg/m³, 4.8× usualSaint Cloud, 11 June: 29.1 µg/m³, 5.3× usualSaint Cloud, 12 June: 27.7 µg/m³, 5.0× usualNepeanNepean, 31 May: 5.9 µg/m³, 0.8× usualNepean, 1 June: no readingNepean, 2 June: no readingNepean, 3 June: 7.6 µg/m³, 1.0× usualNepean, 4 June: 28.0 µg/m³, 3.8× usualNepean, 5 June: 50.2 µg/m³, 6.8× usualNepean, 6 June: 116.0 µg/m³, 16× usualNepean, 7 June: 65.3 µg/m³, 8.8× usualNepean, 8 June: 34.7 µg/m³, 4.7× usualNepean, 9 June: 33.2 µg/m³, 4.5× usualNepean, 10 June: 12.9 µg/m³, 1.7× usualNepean, 11 June: 28.1 µg/m³, 3.8× usualNepean, 12 June: 22.8 µg/m³, 3.1× usualOconomowocOconomowoc, 31 May: 8.1 µg/m³, 1.6× usualOconomowoc, 1 June: no readingOconomowoc, 2 June: no readingOconomowoc, 3 June: 18.5 µg/m³, 3.7× usualOconomowoc, 4 June: 71.9 µg/m³, 14× usualOconomowoc, 5 June: 44.2 µg/m³, 8.8× usualOconomowoc, 6 June: 35.7 µg/m³, 7.1× usualOconomowoc, 7 June: 36.8 µg/m³, 7.4× usualOconomowoc, 8 June: 36.5 µg/m³, 7.3× usualOconomowoc, 9 June: 24.4 µg/m³, 4.9× usualOconomowoc, 10 June: 32.2 µg/m³, 6.4× usualOconomowoc, 11 June: 38.2 µg/m³, 7.6× usualOconomowoc, 12 June: 41.8 µg/m³, 8.4× usualWindsorWindsor, 31 May: 7.9 µg/m³, 1.3× usualWindsor, 1 June: 5.7 µg/m³, 0.9× usualWindsor, 2 June: 7.5 µg/m³, 1.2× usualWindsor, 3 June: 16.7 µg/m³, 2.7× usualWindsor, 4 June: 28.0 µg/m³, 4.5× usualWindsor, 5 June: 48.0 µg/m³, 7.7× usualWindsor, 6 June: 65.2 µg/m³, 11× usualWindsor, 7 June: 25.5 µg/m³, 4.1× usualWindsor, 8 June: 45.9 µg/m³, 7.4× usualWindsor, 9 June: 27.1 µg/m³, 4.4× usualWindsor, 10 June: 16.9 µg/m³, 2.7× usualWindsor, 11 June: 26.0 µg/m³, 4.2× usualWindsor, 12 June: 28.7 µg/m³, 4.6× usualGreen BayGreen Bay, 31 May: 5.1 µg/m³, 0.9× usualGreen Bay, 1 June: 6.0 µg/m³, 1.1× usualGreen Bay, 2 June: 10.1 µg/m³, 1.8× usualGreen Bay, 3 June: 19.2 µg/m³, 3.5× usualGreen Bay, 4 June: 60.8 µg/m³, 11× usualGreen Bay, 5 June: 34.5 µg/m³, 6.3× usualGreen Bay, 6 June: 23.6 µg/m³, 4.3× usualGreen Bay, 7 June: 19.8 µg/m³, 3.6× usualGreen Bay, 8 June: 20.8 µg/m³, 3.8× usualGreen Bay, 9 June: 10.3 µg/m³, 1.9× usualGreen Bay, 10 June: 18.3 µg/m³, 3.3× usualGreen Bay, 11 June: 34.9 µg/m³, 6.3× usualGreen Bay, 12 June: 24.4 µg/m³, 4.4× usualDoltonDolton, 31 May: 8.5 µg/m³, 1.1× usualDolton, 1 June: 8.7 µg/m³, 1.1× usualDolton, 2 June: 11.5 µg/m³, 1.5× usualDolton, 3 June: 18.3 µg/m³, 2.4× usualDolton, 4 June: 41.8 µg/m³, 5.5× usualDolton, 5 June: 60.1 µg/m³, 7.9× usualDolton, 6 June: 37.4 µg/m³, 4.9× usualDolton, 7 June: 24.4 µg/m³, 3.2× usualDolton, 8 June: 26.1 µg/m³, 3.4× usualDolton, 9 June: 22.3 µg/m³, 2.9× usualDolton, 10 June: 21.1 µg/m³, 2.8× usualDolton, 11 June: 26.3 µg/m³, 3.5× usualDolton, 12 June: 29.1 µg/m³, 3.8× usualElmwood ParkElmwood Park, 31 May: 8.8 µg/m³, 1.4× usualElmwood Park, 1 June: 7.1 µg/m³, 1.1× usualElmwood Park, 2 June: 11.3 µg/m³, 1.8× usualElmwood Park, 3 June: 16.2 µg/m³, 2.6× usualElmwood Park, 4 June: 25.5 µg/m³, 4.1× usualElmwood Park, 5 June: 59.7 µg/m³, 9.6× usualElmwood Park, 6 June: 35.5 µg/m³, 5.7× usualElmwood Park, 7 June: 27.2 µg/m³, 4.4× usualElmwood Park, 8 June: 27.0 µg/m³, 4.4× usualElmwood Park, 9 June: 19.4 µg/m³, 3.1× usualElmwood Park, 10 June: 19.7 µg/m³, 3.2× usualElmwood Park, 11 June: 24.7 µg/m³, 4.0× usualElmwood Park, 12 June: 26.8 µg/m³, 4.3× usualAppletonAppleton, 31 May: 6.0 µg/m³, 1.1× usualAppleton, 1 June: 6.5 µg/m³, 1.2× usualAppleton, 2 June: 10.5 µg/m³, 1.9× usualAppleton, 3 June: 20.4 µg/m³, 3.8× usualAppleton, 4 June: 59.0 µg/m³, 11× usualAppleton, 5 June: 30.5 µg/m³, 5.6× usualAppleton, 6 June: 23.8 µg/m³, 4.4× usualAppleton, 7 June: 18.8 µg/m³, 3.5× usualAppleton, 8 June: 24.8 µg/m³, 4.6× usualAppleton, 9 June: 10.1 µg/m³, 1.9× usualAppleton, 10 June: 21.3 µg/m³, 3.9× usualAppleton, 11 June: 31.9 µg/m³, 5.9× usualAppleton, 12 June: 31.3 µg/m³, 5.8× usualHammondHammond, 31 May: 9.0 µg/m³, 1.2× usualHammond, 1 June: 9.2 µg/m³, 1.2× usualHammond, 2 June: 9.8 µg/m³, 1.3× usualHammond, 3 June: 15.5 µg/m³, 2.0× usualHammond, 4 June: 35.0 µg/m³, 4.6× usualHammond, 5 June: 58.3 µg/m³, 7.7× usualHammond, 6 June: 40.5 µg/m³, 5.3× usualHammond, 7 June: 28.1 µg/m³, 3.7× usualHammond, 8 June: 25.5 µg/m³, 3.4× usualHammond, 9 June: 21.5 µg/m³, 2.8× usualHammond, 10 June: 17.0 µg/m³, 2.2× usualHammond, 11 June: 21.7 µg/m³, 2.9× usualHammond, 12 June: 30.4 µg/m³, 4.0× usualSarniaSarnia, 31 May: 3.7 µg/m³, 0.6× usualSarnia, 1 June: 4.1 µg/m³, 0.6× usualSarnia, 2 June: 5.8 µg/m³, 0.9× usualSarnia, 3 June: 14.8 µg/m³, 2.3× usualSarnia, 4 June: 33.3 µg/m³, 5.2× usualSarnia, 5 June: 57.6 µg/m³, 9.0× usualSarnia, 6 June: 29.4 µg/m³, 4.6× usualSarnia, 7 June: 28.4 µg/m³, 4.4× usualSarnia, 8 June: 35.4 µg/m³, 5.5× usualSarnia, 9 June: 25.8 µg/m³, 4.0× usualSarnia, 10 June: 13.0 µg/m³, 2.0× usualSarnia, 11 June: 24.1 µg/m³, 3.8× usualSarnia, 12 June: 24.3 µg/m³, 3.8× usualDearbornDearborn, 31 May: 6.9 µg/m³, 0.8× usualDearborn, 1 June: 4.5 µg/m³, 0.5× usualDearborn, 2 June: 6.9 µg/m³, 0.8× usualDearborn, 3 June: 17.0 µg/m³, 2.0× usualDearborn, 4 June: 25.0 µg/m³, 2.9× usualDearborn, 5 June: 44.2 µg/m³, 5.2× usualDearborn, 6 June: 56.0 µg/m³, 6.6× usualDearborn, 7 June: 21.3 µg/m³, 2.5× usualDearborn, 8 June: 38.3 µg/m³, 4.5× usualDearborn, 9 June: 23.7 µg/m³, 2.8× usualDearborn, 10 June: 15.1 µg/m³, 1.8× usualDearborn, 11 June: 23.9 µg/m³, 2.8× usualDearborn, 12 June: 23.6 µg/m³, 2.8× usualDes PlainesDes Plaines, 31 May: 9.6 µg/m³, 1.4× usualDes Plaines, 1 June: 7.3 µg/m³, 1.0× usualDes Plaines, 2 June: 10.3 µg/m³, 1.5× usualDes Plaines, 3 June: 15.3 µg/m³, 2.2× usualDes Plaines, 4 June: 25.7 µg/m³, 3.6× usualDes Plaines, 5 June: 55.5 µg/m³, 7.8× usualDes Plaines, 6 June: 33.9 µg/m³, 4.8× usualDes Plaines, 7 June: 29.2 µg/m³, 4.1× usualDes Plaines, 8 June: 25.9 µg/m³, 3.6× usualDes Plaines, 9 June: 19.2 µg/m³, 2.7× usualDes Plaines, 10 June: 19.5 µg/m³, 2.7× usualDes Plaines, 11 June: 24.7 µg/m³, 3.5× usualDes Plaines, 12 June: 27.9 µg/m³, 3.9× usualSault Ste. MarieSault Ste. Marie, 31 May: 2.3 µg/m³, 0.4× usualSault Ste. Marie, 1 June: no readingSault Ste. Marie, 2 June: 5.5 µg/m³, 1.0× usualSault Ste. Marie, 3 June: 10.5 µg/m³, 1.9× usualSault Ste. Marie, 4 June: 47.6 µg/m³, 8.8× usualSault Ste. Marie, 5 June: 26.7 µg/m³, 4.9× usualSault Ste. Marie, 6 June: 21.7 µg/m³, 4.0× usualSault Ste. Marie, 7 June: 54.5 µg/m³, 10× usualSault Ste. Marie, 8 June: 36.3 µg/m³, 6.7× usualSault Ste. Marie, 9 June: 18.0 µg/m³, 3.3× usualSault Ste. Marie, 10 June: 9.5 µg/m³, 1.8× usualSault Ste. Marie, 11 June: 17.2 µg/m³, 3.2× usualSault Ste. Marie, 12 June: 9.4 µg/m³, 1.7× usualEast ChicagoEast Chicago, 31 May: 8.8 µg/m³, 1.2× usualEast Chicago, 1 June: 5.7 µg/m³, 0.8× usualEast Chicago, 2 June: 9.2 µg/m³, 1.3× usualEast Chicago, 3 June: 14.6 µg/m³, 2.0× usualEast Chicago, 4 June: 38.7 µg/m³, 5.3× usualEast Chicago, 5 June: 54.4 µg/m³, 7.5× usualEast Chicago, 6 June: 34.5 µg/m³, 4.7× usualEast Chicago, 7 June: 22.7 µg/m³, 3.1× usualEast Chicago, 8 June: 21.6 µg/m³, 3.0× usualEast Chicago, 9 June: 18.5 µg/m³, 2.5× usualEast Chicago, 10 June: 16.7 µg/m³, 2.3× usualEast Chicago, 11 June: 20.9 µg/m³, 2.9× usualEast Chicago, 12 June: 25.9 µg/m³, 3.5× usualCalumet CityCalumet City, 31 May: 9.2 µg/m³, 1.2× usualCalumet City, 1 June: 9.2 µg/m³, 1.2× usualCalumet City, 2 June: 10.2 µg/m³, 1.3× usualCalumet City, 3 June: 15.5 µg/m³, 2.0× usualCalumet City, 4 June: 28.2 µg/m³, 3.7× usualCalumet City, 5 June: 54.1 µg/m³, 7.0× usualCalumet City, 6 June: 35.8 µg/m³, 4.6× usualCalumet City, 7 June: 25.0 µg/m³, 3.2× usualCalumet City, 8 June: 24.2 µg/m³, 3.1× usualCalumet City, 9 June: 19.0 µg/m³, 2.5× usualCalumet City, 10 June: 16.7 µg/m³, 2.2× usualCalumet City, 11 June: 21.2 µg/m³, 2.8× usualCalumet City, 12 June: 26.8 µg/m³, 3.5× usualOttawaOttawa, 31 May: 4.0 µg/m³, 0.7× usualOttawa, 1 June: 1.4 µg/m³, 0.3× usualOttawa, 2 June: 3.4 µg/m³, 0.6× usualOttawa, 3 June: 6.4 µg/m³, 1.2× usualOttawa, 4 June: 15.5 µg/m³, 2.8× usualOttawa, 5 June: 32.1 µg/m³, 5.8× usualOttawa, 6 June: 89.6 µg/m³, 16× usualOttawa, 7 June: 46.8 µg/m³, 8.5× usualOttawa, 8 June: 20.1 µg/m³, 3.7× usualOttawa, 9 June: 20.5 µg/m³, 3.7× usualOttawa, 10 June: 7.4 µg/m³, 1.3× usualOttawa, 11 June: 13.2 µg/m³, 2.4× usualOttawa, 12 June: 11.0 µg/m³, 2.0× usualL'Ancienne-LoretteL'Ancienne-Lorette, 31 May: 5.4 µg/m³, 0.9× usualL'Ancienne-Lorette, 1 June: 1.7 µg/m³, 0.3× usualL'Ancienne-Lorette, 2 June: 3.8 µg/m³, 0.6× usualL'Ancienne-Lorette, 3 June: 5.8 µg/m³, 1.0× usualL'Ancienne-Lorette, 4 June: 14.5 µg/m³, 2.4× usualL'Ancienne-Lorette, 5 June: 26.2 µg/m³, 4.3× usualL'Ancienne-Lorette, 6 June: 73.3 µg/m³, 12× usualL'Ancienne-Lorette, 7 June: 50.2 µg/m³, 8.2× usualL'Ancienne-Lorette, 8 June: 10.5 µg/m³, 1.7× usualL'Ancienne-Lorette, 9 June: 14.0 µg/m³, 2.3× usualL'Ancienne-Lorette, 10 June: 13.7 µg/m³, 2.2× usualL'Ancienne-Lorette, 11 June: 13.1 µg/m³, 2.1× usualL'Ancienne-Lorette, 12 June: 10.0 µg/m³, 1.6× usualCornwallCornwall, 31 May: 4.7 µg/m³, 0.8× usualCornwall, 1 June: 1.8 µg/m³, 0.3× usualCornwall, 2 June: 3.7 µg/m³, 0.6× usualCornwall, 3 June: 6.8 µg/m³, 1.2× usualCornwall, 4 June: 16.8 µg/m³, 2.9× usualCornwall, 5 June: 25.1 µg/m³, 4.4× usualCornwall, 6 June: 70.3 µg/m³, 12× usualCornwall, 7 June: 48.8 µg/m³, 8.6× usualCornwall, 8 June: 29.3 µg/m³, 5.1× usualCornwall, 9 June: 19.7 µg/m³, 3.5× usualCornwall, 10 June: 7.2 µg/m³, 1.3× usualCornwall, 11 June: 14.5 µg/m³, 2.5× usualCornwall, 12 June: 16.7 µg/m³, 2.9× usualTorontoToronto, 31 May: 5.8 µg/m³, 0.8× usualToronto, 1 June: 3.0 µg/m³, 0.4× usualToronto, 2 June: 5.9 µg/m³, 0.9× usualToronto, 3 June: 10.5 µg/m³, 1.5× usualToronto, 4 June: 20.2 µg/m³, 2.9× usualToronto, 5 June: 29.6 µg/m³, 4.3× usualToronto, 6 June: 67.9 µg/m³, 9.8× usualToronto, 7 June: 31.4 µg/m³, 4.6× usualToronto, 8 June: 37.8 µg/m³, 5.5× usualToronto, 9 June: 21.3 µg/m³, 3.1× usualToronto, 10 June: 10.8 µg/m³, 1.6× usualToronto, 11 June: 21.5 µg/m³, 3.1× usualToronto, 12 June: 18.4 µg/m³, 2.7× usualSaguenaySaguenay, 31 May: 7.0 µg/m³, 1.1× usualSaguenay, 1 June: 1.9 µg/m³, 0.3× usualSaguenay, 2 June: 2.8 µg/m³, 0.5× usualSaguenay, 3 June: 7.0 µg/m³, 1.1× usualSaguenay, 4 June: 15.8 µg/m³, 2.5× usualSaguenay, 5 June: 41.6 µg/m³, 6.7× usualSaguenay, 6 June: 66.9 µg/m³, 11× usualSaguenay, 7 June: 27.6 µg/m³, 4.5× usualSaguenay, 8 June: 8.9 µg/m³, 1.4× usualSaguenay, 9 June: 15.2 µg/m³, 2.5× usualSaguenay, 10 June: 16.1 µg/m³, 2.6× usualSaguenay, 11 June: 11.8 µg/m³, 1.9× usualSaguenay, 12 June: 6.4 µg/m³, 1.0× usualPeterboroughPeterborough, 31 May: 3.1 µg/m³, 0.6× usualPeterborough, 1 June: 2.1 µg/m³, 0.4× usualPeterborough, 2 June: 3.3 µg/m³, 0.6× usualPeterborough, 3 June: 8.0 µg/m³, 1.5× usualPeterborough, 4 June: 15.7 µg/m³, 2.9× usualPeterborough, 5 June: 30.8 µg/m³, 5.7× usualPeterborough, 6 June: 66.2 µg/m³, 12× usualPeterborough, 7 June: 39.5 µg/m³, 7.3× usualPeterborough, 8 June: 32.1 µg/m³, 5.9× usualPeterborough, 9 June: 11.8 µg/m³, 2.2× usualPeterborough, 10 June: 8.1 µg/m³, 1.5× usualPeterborough, 11 June: 15.9 µg/m³, 2.9× usualPeterborough, 12 June: 16.1 µg/m³, 3.0× usualKitchenerKitchener, 31 May: 4.7 µg/m³, 0.6× usualKitchener, 1 June: 3.0 µg/m³, 0.4× usualKitchener, 2 June: 4.4 µg/m³, 0.6× usualKitchener, 3 June: 10.1 µg/m³, 1.4× usualKitchener, 4 June: 17.7 µg/m³, 2.4× usualKitchener, 5 June: 44.7 µg/m³, 6.0× usualKitchener, 6 June: 63.9 µg/m³, 8.6× usualKitchener, 7 June: 24.4 µg/m³, 3.3× usualKitchener, 8 June: 37.0 µg/m³, 5.0× usualKitchener, 9 June: 21.5 µg/m³, 2.9× usualKitchener, 10 June: 10.8 µg/m³, 1.5× usualKitchener, 11 June: 22.0 µg/m³, 3.0× usualKitchener, 12 June: 18.2 µg/m³, 2.5× usualMiltonMilton, 31 May: 5.1 µg/m³, 0.9× usualMilton, 1 June: 3.0 µg/m³, 0.5× usualMilton, 2 June: 4.3 µg/m³, 0.7× usualMilton, 3 June: 10.5 µg/m³, 1.8× usualMilton, 4 June: 20.0 µg/m³, 3.4× usualMilton, 5 June: 38.0 µg/m³, 6.4× usualMilton, 6 June: 62.8 µg/m³, 11× usualMilton, 7 June: 28.7 µg/m³, 4.9× usualMilton, 8 June: 37.1 µg/m³, 6.3× usualMilton, 9 June: 23.2 µg/m³, 3.9× usualMilton, 10 June: 10.6 µg/m³, 1.8× usualMilton, 11 June: 22.0 µg/m³, 3.7× usualMilton, 12 June: 17.5 µg/m³, 3.0× usualFranklin ParkFranklin Park, 31 May: 9.4 µg/m³, 1.2× usualFranklin Park, 1 June: 8.6 µg/m³, 1.1× usualFranklin Park, 2 June: 10.6 µg/m³, 1.3× usualFranklin Park, 3 June: 16.2 µg/m³, 2.0× usualFranklin Park, 4 June: 23.7 µg/m³, 2.9× usualFranklin Park, 5 June: 59.5 µg/m³, 7.3× usualFranklin Park, 6 June: 35.6 µg/m³, 4.4× usualFranklin Park, 7 June: 32.3 µg/m³, 4.0× usualFranklin Park, 8 June: 27.6 µg/m³, 3.4× usualFranklin Park, 9 June: 20.4 µg/m³, 2.5× usualFranklin Park, 10 June: 20.9 µg/m³, 2.6× usualFranklin Park, 11 June: 26.3 µg/m³, 3.2× usualFranklin Park, 12 June: 30.3 µg/m³, 3.7× usualChicagoChicago, 31 May: 8.1 µg/m³, 1.1× usualChicago, 1 June: 7.7 µg/m³, 1.0× usualChicago, 2 June: 9.7 µg/m³, 1.3× usualChicago, 3 June: 15.8 µg/m³, 2.1× usualChicago, 4 June: 20.8 µg/m³, 2.7× usualChicago, 5 June: 58.4 µg/m³, 7.7× usualChicago, 6 June: 35.2 µg/m³, 4.6× usualChicago, 7 June: 26.3 µg/m³, 3.5× usualChicago, 8 June: 27.2 µg/m³, 3.6× usualChicago, 9 June: 18.7 µg/m³, 2.5× usualChicago, 10 June: 18.1 µg/m³, 2.4× usualChicago, 11 June: 24.2 µg/m³, 3.2× usualChicago, 12 June: 27.8 µg/m³, 3.7× usualLincoln ParkLincoln Park, 31 May: 6.9 µg/m³, 0.9× usualLincoln Park, 1 June: 5.3 µg/m³, 0.7× usualLincoln Park, 2 June: 6.5 µg/m³, 0.9× usualLincoln Park, 3 June: 14.0 µg/m³, 1.9× usualLincoln Park, 4 June: 21.7 µg/m³, 2.9× usualLincoln Park, 5 June: 41.4 µg/m³, 5.5× usualLincoln Park, 6 June: 56.8 µg/m³, 7.6× usualLincoln Park, 7 June: 21.0 µg/m³, 2.8× usualLincoln Park, 8 June: 38.6 µg/m³, 5.1× usualLincoln Park, 9 June: 20.7 µg/m³, 2.8× usualLincoln Park, 10 June: 12.9 µg/m³, 1.7× usualLincoln Park, 11 June: 20.0 µg/m³, 2.7× usualLincoln Park, 12 June: 24.2 µg/m³, 3.2× usualSouthfieldSouthfield, 31 May: 6.5 µg/m³, 1.2× usualSouthfield, 1 June: 4.4 µg/m³, 0.8× usualSouthfield, 2 June: 6.4 µg/m³, 1.2× usualSouthfield, 3 June: 16.0 µg/m³, 3.0× usualSouthfield, 4 June: 20.0 µg/m³, 3.8× usualSouthfield, 5 June: 48.7 µg/m³, 9.2× usualSouthfield, 6 June: 56.1 µg/m³, 11× usualSouthfield, 7 June: 20.7 µg/m³, 3.9× usualSouthfield, 8 June: 38.5 µg/m³, 7.3× usualSouthfield, 9 June: 24.1 µg/m³, 4.5× usualSouthfield, 10 June: 13.5 µg/m³, 2.5× usualSouthfield, 11 June: 23.8 µg/m³, 4.5× usualSouthfield, 12 June: 24.0 µg/m³, 4.5× usualYpsilantiYpsilanti, 31 May: 7.2 µg/m³, 1.1× usualYpsilanti, 1 June: 4.5 µg/m³, 0.7× usualYpsilanti, 2 June: 6.7 µg/m³, 1.0× usualYpsilanti, 3 June: 15.5 µg/m³, 2.3× usualYpsilanti, 4 June: 14.9 µg/m³, 2.3× usualYpsilanti, 5 June: 39.6 µg/m³, 6.0× usualYpsilanti, 6 June: 56.0 µg/m³, 8.5× usualYpsilanti, 7 June: 26.4 µg/m³, 4.0× usualYpsilanti, 8 June: 37.8 µg/m³, 5.7× usualYpsilanti, 9 June: 20.8 µg/m³, 3.2× usualYpsilanti, 10 June: 12.8 µg/m³, 1.9× usualYpsilanti, 11 June: 19.3 µg/m³, 2.9× usualYpsilanti, 12 June: 23.9 µg/m³, 3.6× usualDetroitDetroit, 31 May: 6.8 µg/m³, 0.8× usualDetroit, 1 June: 5.9 µg/m³, 0.7× usualDetroit, 2 June: 7.6 µg/m³, 0.9× usualDetroit, 3 June: 16.0 µg/m³, 2.0× usualDetroit, 4 June: 24.3 µg/m³, 3.0× usualDetroit, 5 June: 41.3 µg/m³, 5.0× usualDetroit, 6 June: 55.9 µg/m³, 6.8× usualDetroit, 7 June: 22.1 µg/m³, 2.7× usualDetroit, 8 June: 38.0 µg/m³, 4.6× usualDetroit, 9 June: 23.0 µg/m³, 2.8× usualDetroit, 10 June: 14.4 µg/m³, 1.8× usualDetroit, 11 June: 23.3 µg/m³, 2.8× usualDetroit, 12 June: 23.8 µg/m³, 2.9× usualGuelphGuelph, 31 May: 4.3 µg/m³, 0.8× usualGuelph, 1 June: 3.1 µg/m³, 0.6× usualGuelph, 2 June: 4.6 µg/m³, 0.8× usualGuelph, 3 June: 10.2 µg/m³, 1.9× usualGuelph, 4 June: 16.7 µg/m³, 3.0× usualGuelph, 5 June: 46.0 µg/m³, 8.4× usualGuelph, 6 June: 54.9 µg/m³, 10.0× usualGuelph, 7 June: 24.5 µg/m³, 4.5× usualGuelph, 8 June: 35.0 µg/m³, 6.4× usualGuelph, 9 June: 23.0 µg/m³, 4.2× usualGuelph, 10 June: 10.4 µg/m³, 1.9× usualGuelph, 11 June: 20.1 µg/m³, 3.7× usualGuelph, 12 June: 16.0 µg/m³, 2.9× usualBramptonBrampton, 31 May: 4.9 µg/m³, 0.9× usualBrampton, 1 June: 2.3 µg/m³, 0.4× usualBrampton, 2 June: 3.9 µg/m³, 0.7× usualBrampton, 3 June: 9.3 µg/m³, 1.7× usualBrampton, 4 June: 16.5 µg/m³, 2.9× usualBrampton, 5 June: 31.5 µg/m³, 5.6× usualBrampton, 6 June: 54.6 µg/m³, 9.8× usualBrampton, 7 June: 27.5 µg/m³, 4.9× usualBrampton, 8 June: 33.8 µg/m³, 6.0× usualBrampton, 9 June: 20.7 µg/m³, 3.7× usualBrampton, 10 June: 9.3 µg/m³, 1.7× usualBrampton, 11 June: 19.4 µg/m³, 3.5× usualBrampton, 12 June: 15.6 µg/m³, 2.8× usualBellevilleBelleville, 31 May: 3.9 µg/m³, 0.7× usualBelleville, 1 June: 1.7 µg/m³, 0.3× usualBelleville, 2 June: 3.5 µg/m³, 0.6× usualBelleville, 3 June: 5.8 µg/m³, 1.1× usualBelleville, 4 June: 17.4 µg/m³, 3.2× usualBelleville, 5 June: 21.4 µg/m³, 3.9× usualBelleville, 6 June: 79.5 µg/m³, 14× usualBelleville, 7 June: 47.4 µg/m³, 8.6× usualBelleville, 8 June: 34.0 µg/m³, 6.2× usualBelleville, 9 June: 9.5 µg/m³, 1.7× usualBelleville, 10 June: 6.6 µg/m³, 1.2× usualBelleville, 11 June: 15.3 µg/m³, 2.8× usualBelleville, 12 June: 18.8 µg/m³, 3.4× usualSept-ÎlesSept-Îles, 31 May: 5.9 µg/m³, 1.2× usualSept-Îles, 1 June: 4.5 µg/m³, 0.9× usualSept-Îles, 2 June: 5.6 µg/m³, 1.1× usualSept-Îles, 3 June: 2.3 µg/m³, 0.5× usualSept-Îles, 4 June: 4.9 µg/m³, 1.0× usualSept-Îles, 5 June: 8.5 µg/m³, 1.7× usualSept-Îles, 6 June: 78.0 µg/m³, 16× usualSept-Îles, 7 June: 37.2 µg/m³, 7.4× usualSept-Îles, 8 June: 5.3 µg/m³, 1.1× usualSept-Îles, 9 June: 10.6 µg/m³, 2.1× usualSept-Îles, 10 June: 13.7 µg/m³, 2.7× usualSept-Îles, 11 June: 4.6 µg/m³, 0.9× usualSept-Îles, 12 June: 4.8 µg/m³, 1.0× usualDorvalDorval, 31 May: 5.9 µg/m³, 1.0× usualDorval, 1 June: 1.5 µg/m³, 0.2× usualDorval, 2 June: 2.9 µg/m³, 0.5× usualDorval, 3 June: 5.6 µg/m³, 0.9× usualDorval, 4 June: 16.8 µg/m³, 2.7× usualDorval, 5 June: 17.9 µg/m³, 2.9× usualDorval, 6 June: 68.9 µg/m³, 11× usualDorval, 7 June: 52.7 µg/m³, 8.5× usualDorval, 8 June: 25.5 µg/m³, 4.1× usualDorval, 9 June: 27.7 µg/m³, 4.5× usualDorval, 10 June: 8.2 µg/m³, 1.3× usualDorval, 11 June: 15.0 µg/m³, 2.4× usualDorval, 12 June: 15.4 µg/m³, 2.5× usualMontréalMontréal, 31 May: 6.3 µg/m³, 1.0× usualMontréal, 1 June: 1.9 µg/m³, 0.3× usualMontréal, 2 June: 3.6 µg/m³, 0.6× usualMontréal, 3 June: 6.1 µg/m³, 1.0× usualMontréal, 4 June: 17.2 µg/m³, 2.7× usualMontréal, 5 June: 18.7 µg/m³, 3.0× usualMontréal, 6 June: 68.1 µg/m³, 11× usualMontréal, 7 June: 52.1 µg/m³, 8.3× usualMontréal, 8 June: 23.9 µg/m³, 3.8× usualMontréal, 9 June: 26.7 µg/m³, 4.2× usualMontréal, 10 June: 8.0 µg/m³, 1.3× usualMontréal, 11 June: 15.2 µg/m³, 2.4× usualMontréal, 12 June: 16.0 µg/m³, 2.5× usualBrantfordBrantford, 31 May: 9.4 µg/m³, 1.2× usualBrantford, 1 June: 2.6 µg/m³, 0.3× usualBrantford, 2 June: 3.9 µg/m³, 0.5× usualBrantford, 3 June: 9.1 µg/m³, 1.1× usualBrantford, 4 June: 18.6 µg/m³, 2.3× usualBrantford, 5 June: 17.3 µg/m³, 2.1× usualBrantford, 6 June: 67.5 µg/m³, 8.3× usualBrantford, 7 June: 28.8 µg/m³, 3.6× usualBrantford, 8 June: 39.7 µg/m³, 4.9× usualBrantford, 9 June: 20.4 µg/m³, 2.5× usualBrantford, 10 June: 8.6 µg/m³, 1.1× usualBrantford, 11 June: 19.5 µg/m³, 2.4× usualBrantford, 12 June: 21.6 µg/m³, 2.7× usualOakvilleOakville, 31 May: 5.7 µg/m³, 0.9× usualOakville, 1 June: 2.7 µg/m³, 0.4× usualOakville, 2 June: 3.9 µg/m³, 0.6× usualOakville, 3 June: 9.0 µg/m³, 1.5× usualOakville, 4 June: 18.5 µg/m³, 3.0× usualOakville, 5 June: 19.2 µg/m³, 3.1× usualOakville, 6 June: 63.8 µg/m³, 10× usualOakville, 7 June: 29.3 µg/m³, 4.8× usualOakville, 8 June: 36.9 µg/m³, 6.0× usualOakville, 9 June: 21.2 µg/m³, 3.5× usualOakville, 10 June: 8.8 µg/m³, 1.4× usualOakville, 11 June: 19.7 µg/m³, 3.2× usualOakville, 12 June: 16.7 µg/m³, 2.7× usualLondonLondon, 31 May: 5.6 µg/m³, 0.8× usualLondon, 1 June: 3.1 µg/m³, 0.4× usualLondon, 2 June: 5.9 µg/m³, 0.8× usualLondon, 3 June: no readingLondon, 4 June: 18.2 µg/m³, 2.6× usualLondon, 5 June: 20.3 µg/m³, 2.9× usualLondon, 6 June: 63.4 µg/m³, 9.1× usualLondon, 7 June: 29.0 µg/m³, 4.1× usualLondon, 8 June: 37.1 µg/m³, 5.3× usualLondon, 9 June: 18.1 µg/m³, 2.6× usualLondon, 10 June: 10.2 µg/m³, 1.5× usualLondon, 11 June: 21.0 µg/m³, 3.0× usualLondon, 12 June: 20.8 µg/m³, 3.0× usualQuébecQuébec, 31 May: 4.7 µg/m³, 0.9× usualQuébec, 1 June: 1.6 µg/m³, 0.3× usualQuébec, 2 June: 3.3 µg/m³, 0.6× usualQuébec, 3 June: 5.8 µg/m³, 1.1× usualQuébec, 4 June: 13.8 µg/m³, 2.6× usualQuébec, 5 June: 19.7 µg/m³, 3.6× usualQuébec, 6 June: 60.6 µg/m³, 11× usualQuébec, 7 June: 47.9 µg/m³, 8.9× usualQuébec, 8 June: 11.8 µg/m³, 2.2× usualQuébec, 9 June: 13.1 µg/m³, 2.4× usualQuébec, 10 June: 12.5 µg/m³, 2.3× usualQuébec, 11 June: 12.4 µg/m³, 2.3× usualQuébec, 12 June: 9.6 µg/m³, 1.8× usualRivière-des-Prairie…Rivière-des-Prairies–Pointe-aux-Trembles, 31 May: 5.3 µg/m³, 0.9× usualRivière-des-Prairies–Pointe-aux-Trembles, 1 June: 1.6 µg/m³, 0.3× usualRivière-des-Prairies–Pointe-aux-Trembles, 2 June: 3.4 µg/m³, 0.6× usualRivière-des-Prairies–Pointe-aux-Trembles, 3 June: 5.8 µg/m³, 1.0× usualRivière-des-Prairies–Pointe-aux-Trembles, 4 June: 15.4 µg/m³, 2.7× usualRivière-des-Prairies–Pointe-aux-Trembles, 5 June: 16.4 µg/m³, 2.9× usualRivière-des-Prairies–Pointe-aux-Trembles, 6 June: 60.6 µg/m³, 11× usualRivière-des-Prairies–Pointe-aux-Trembles, 7 June: 43.5 µg/m³, 7.6× usualRivière-des-Prairies–Pointe-aux-Trembles, 8 June: 19.9 µg/m³, 3.5× usualRivière-des-Prairies–Pointe-aux-Trembles, 9 June: 23.4 µg/m³, 4.1× usualRivière-des-Prairies–Pointe-aux-Trembles, 10 June: 7.6 µg/m³, 1.3× usualRivière-des-Prairies–Pointe-aux-Trembles, 11 June: 13.9 µg/m³, 2.4× usualRivière-des-Prairies–Pointe-aux-Trembles, 12 June: 13.7 µg/m³, 2.4× usualKingstonKingston, 31 May: 4.0 µg/m³, 0.8× usualKingston, 1 June: 1.3 µg/m³, 0.2× usualKingston, 2 June: 3.3 µg/m³, 0.6× usualKingston, 3 June: 5.0 µg/m³, 0.9× usualKingston, 4 June: 13.5 µg/m³, 2.5× usualKingston, 5 June: 14.0 µg/m³, 2.6× usualKingston, 6 June: 59.5 µg/m³, 11× usualKingston, 7 June: 45.4 µg/m³, 8.6× usualKingston, 8 June: 30.3 µg/m³, 5.7× usualKingston, 9 June: 9.4 µg/m³, 1.8× usualKingston, 10 June: 6.0 µg/m³, 1.1× usualKingston, 11 June: 14.9 µg/m³, 2.8× usualKingston, 12 June: 18.9 µg/m³, 3.6× usualHamiltonHamilton, 31 May: 5.6 µg/m³, 0.7× usualHamilton, 1 June: 2.8 µg/m³, 0.3× usualHamilton, 2 June: 3.9 µg/m³, 0.5× usualHamilton, 3 June: 8.6 µg/m³, 1.0× usualHamilton, 4 June: 19.4 µg/m³, 2.4× usualHamilton, 5 June: 17.1 µg/m³, 2.1× usualHamilton, 6 June: 59.1 µg/m³, 7.2× usualHamilton, 7 June: 32.9 µg/m³, 4.0× usualHamilton, 8 June: 40.8 µg/m³, 5.0× usualHamilton, 9 June: 21.7 µg/m³, 2.6× usualHamilton, 10 June: 8.3 µg/m³, 1.0× usualHamilton, 11 June: 19.1 µg/m³, 2.3× usualHamilton, 12 June: 20.4 µg/m³, 2.5× usualSorel-TracySorel-Tracy, 31 May: 5.7 µg/m³, 0.8× usualSorel-Tracy, 1 June: 13.2 µg/m³, 1.9× usualSorel-Tracy, 2 June: 5.4 µg/m³, 0.8× usualSorel-Tracy, 3 June: 5.9 µg/m³, 0.8× usualSorel-Tracy, 4 June: 14.7 µg/m³, 2.1× usualSorel-Tracy, 5 June: 23.8 µg/m³, 3.4× usualSorel-Tracy, 6 June: 58.9 µg/m³, 8.4× usualSorel-Tracy, 7 June: 40.3 µg/m³, 5.8× usualSorel-Tracy, 8 June: 13.0 µg/m³, 1.9× usualSorel-Tracy, 9 June: 17.8 µg/m³, 2.5× usualSorel-Tracy, 10 June: 8.2 µg/m³, 1.2× usualSorel-Tracy, 11 June: 14.5 µg/m³, 2.1× usualSorel-Tracy, 12 June: 15.3 µg/m³, 2.2× usualShawiniganShawinigan, 31 May: 5.8 µg/m³, 1.0× usualShawinigan, 1 June: 1.0 µg/m³, 0.2× usualShawinigan, 2 June: 3.1 µg/m³, 0.5× usualShawinigan, 3 June: 5.7 µg/m³, 1.0× usualShawinigan, 4 June: 13.9 µg/m³, 2.3× usualShawinigan, 5 June: 19.2 µg/m³, 3.2× usualShawinigan, 6 June: 57.1 µg/m³, 9.5× usualShawinigan, 7 June: 37.5 µg/m³, 6.3× usualShawinigan, 8 June: 8.7 µg/m³, 1.5× usualShawinigan, 9 June: 16.8 µg/m³, 2.8× usualShawinigan, 10 June: 9.4 µg/m³, 1.6× usualShawinigan, 11 June: 11.6 µg/m³, 1.9× usualShawinigan, 12 June: 8.8 µg/m³, 1.5× usualMississaugaMississauga, 31 May: 5.0 µg/m³, 0.9× usualMississauga, 1 June: 2.2 µg/m³, 0.4× usualMississauga, 2 June: 3.5 µg/m³, 0.6× usualMississauga, 3 June: 8.6 µg/m³, 1.6× usualMississauga, 4 June: 16.5 µg/m³, 3.0× usualMississauga, 5 June: 20.0 µg/m³, 3.6× usualMississauga, 6 June: 56.4 µg/m³, 10× usualMississauga, 7 June: 27.2 µg/m³, 4.9× usualMississauga, 8 June: 33.9 µg/m³, 6.2× usualMississauga, 9 June: 21.3 µg/m³, 3.9× usualMississauga, 10 June: 8.5 µg/m³, 1.5× usualMississauga, 11 June: 18.6 µg/m³, 3.4× usualMississauga, 12 June: 15.8 µg/m³, 2.9× usualTrois-RivièresTrois-Rivières, 31 May: 5.7 µg/m³, 0.9× usualTrois-Rivières, 1 June: 1.5 µg/m³, 0.2× usualTrois-Rivières, 2 June: 3.5 µg/m³, 0.6× usualTrois-Rivières, 3 June: 6.5 µg/m³, 1.1× usualTrois-Rivières, 4 June: 13.3 µg/m³, 2.2× usualTrois-Rivières, 5 June: 18.5 µg/m³, 3.0× usualTrois-Rivières, 6 June: 55.2 µg/m³, 9.0× usualTrois-Rivières, 7 June: 40.9 µg/m³, 6.7× usualTrois-Rivières, 8 June: 13.7 µg/m³, 2.2× usualTrois-Rivières, 9 June: 19.0 µg/m³, 3.1× usualTrois-Rivières, 10 June: 7.7 µg/m³, 1.3× usualTrois-Rivières, 11 June: 13.7 µg/m³, 2.2× usualTrois-Rivières, 12 June: 11.6 µg/m³, 1.9× usualBrossardBrossard, 31 May: 6.1 µg/m³, 1.0× usualBrossard, 1 June: 1.5 µg/m³, 0.2× usualBrossard, 2 June: 2.9 µg/m³, 0.5× usualBrossard, 3 June: 5.0 µg/m³, 0.8× usualBrossard, 4 June: 14.3 µg/m³, 2.3× usualBrossard, 5 June: 17.1 µg/m³, 2.8× usualBrossard, 6 June: 55.1 µg/m³, 9.0× usualBrossard, 7 June: 36.4 µg/m³, 6.0× usualBrossard, 8 June: 24.3 µg/m³, 4.0× usualBrossard, 9 June: 24.2 µg/m³, 4.0× usualBrossard, 10 June: 6.6 µg/m³, 1.1× usualBrossard, 11 June: 13.7 µg/m³, 2.2× usualBrossard, 12 June: 15.2 µg/m³, 2.5× usual31 May1 Jun24681012
The 60 cities with the highest readings of 196, 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
MarquetteMichigan, United States1 98.23 June3.720×
DuluthMinnesota, United States1 96.03 June4.719×
BlaineMinnesota, United States2 90.53 June5.217×
OttawaOntario, Canada3 89.66 June5.516×
SuperiorWisconsin, United States1 88.73 June5.516×
NepeanOntario, Canada5 116.06 June7.416×
Sept-ÎlesQuebec, Canada2 78.06 June3.516×
MankatoMinnesota, United States1 85.03 June5.715×
Saint MichaelMinnesota, United States1 81.23 June5.615×
BellevilleOntario, Canada3 79.56 June5.514×
OconomowocWisconsin, United States5 71.94 June4.514×
MinneapolisMinnesota, United States2 90.23 June6.414×
ShakopeeMinnesota, United States1 84.23 June6.014×
Apple ValleyMinnesota, United States2 78.33 June5.714×
Saint PaulMinnesota, United States2 80.93 June6.113×
BurnsvilleMinnesota, United States1 79.73 June6.412×
CornwallOntario, Canada4 70.36 June5.712×
PeterboroughOntario, Canada4 66.26 June5.412×
L'Ancienne-LoretteQuebec, Canada3 73.36 June6.112×
Eau ClaireWisconsin, United States2 63.23 June5.511×
KingstonOntario, Canada3 59.56 June5.311×
QuébecQuebec, Canada2 60.66 June5.411×
DorvalQuebec, Canada4 68.96 June6.211×
Green BayWisconsin, United States2 60.84 June5.511×
AppletonWisconsin, United States2 59.04 June5.411×
MontréalQuebec, Canada3 68.16 June6.311×
SaguenayQuebec, Canada3 66.96 June6.211×
MiltonOntario, Canada4 62.86 June5.911×
Rivière-des-Prairies–Pointe-aux-TremblesQuebec, Canada2 60.66 June5.711×
SouthfieldMichigan, United States3 56.16 June5.311×
WindsorOntario, Canada5 65.26 June6.211×
OakvilleOntario, Canada3 63.86 June6.110×
MississaugaOntario, Canada3 56.46 June5.510×
Sault Ste. MarieOntario, Canada4 54.57 June5.410×
GuelphOntario, Canada3 54.96 June5.510.0×
Saint CloudMinnesota, United States1 54.73 June5.59.9×
TorontoOntario, Canada4 67.96 June6.99.8×
BramptonOntario, Canada4 54.66 June5.69.8×
Elmwood ParkIllinois, United States5 59.75 June6.29.6×
ShawiniganQuebec, Canada2 57.16 June6.09.5×
EdmundstonNew Brunswick, Canada2 46.37 June5.09.3×
EastpointeMichigan, United States3 52.66 June5.79.2×
LondonOntario, Canada3 63.46 June7.09.1×
Trois-RivièresQuebec, Canada2 55.26 June6.19.0×
MadisonWisconsin, United States3 49.74 June5.59.0×
BrossardQuebec, Canada2 55.16 June6.19.0×
SarniaOntario, Canada5 57.65 June6.49.0×
Rouyn-NorandaQuebec, Canada3 49.45 June5.59.0×
RochesterMinnesota, United States3 61.93 June7.08.8×
ElginIllinois, United States3 47.45 June5.48.8×
Cedar RapidsIowa, United States5 43.84 June4.98.8×
Michigan CityIndiana, United States4 53.45 June6.18.8×
NewmarketOntario, Canada4 53.76 June6.28.7×
KitchenerOntario, Canada3 63.96 June7.48.6×
WaterdownOntario, Canada3 49.76 June5.88.6×
Port HuronMichigan, United States5 53.95 June6.38.6×
AuroraIllinois, United States3 45.35 June5.38.5×
Saint-Jean-sur-RichelieuQuebec, Canada2 42.56 June4.88.5×
YpsilantiMichigan, United States4 56.06 June6.68.5×
Sorel-TracyQuebec, Canada2 58.96 June7.08.4×
BrantfordOntario, Canada3 67.56 June8.18.3×
DoltonIllinois, United States4 60.15 June7.67.9×
ZionIllinois, United States3 44.24 June5.67.9×
TaylorMichigan, United States3 53.66 June6.87.9×
GranbyQuebec, Canada3 44.06 June5.67.9×
Des PlainesIllinois, United States5 55.55 June7.17.8×
ChicagoIllinois, United States4 58.45 June7.67.7×
HammondIndiana, United States5 58.35 June7.67.7×
RochesterNew York, United States2 45.87 June6.07.6×
ChathamOntario, Canada3 45.56 June6.07.6×
Lincoln ParkMichigan, United States3 56.86 June7.57.6×
AllistonOntario, Canada4 37.36 June4.47.5×
East ChicagoIndiana, United States3 54.45 June7.37.5×
Franklin ParkIllinois, United States4 59.55 June8.17.3×
Greater SudburyOntario, Canada3 43.57 June6.07.3×
SyracuseNew York, United States2 37.58 June5.27.2×
HamiltonOntario, Canada3 59.16 June8.27.2×
BridgeviewIllinois, United States4 53.35 June7.57.1×
Calumet CityIllinois, United States4 54.15 June7.77.0×
St. ThomasOntario, Canada3 47.66 June6.96.9×
BloomingtonIllinois, United States3 42.45 June6.26.8×
North BayOntario, Canada2 36.27 June5.36.8×
DetroitMichigan, United States3 55.96 June8.26.8×
SherbrookeQuebec, Canada1 34.07 June4.56.8×
NorthbrookIllinois, United States3 46.65 June6.96.8×
DrummondvilleQuebec, Canada2 38.96 June5.86.7×
Oak LawnIllinois, United States3 48.95 June7.36.7×
DearbornMichigan, United States4 56.06 June8.56.6×
CaryIllinois, United States3 45.25 June6.96.6×
LansingMichigan, United States3 43.95 June6.86.5×
NapervilleIllinois, United States3 50.35 June7.86.4×
South MilwaukeeWisconsin, United States3 40.55 June6.36.4×
JolietIllinois, United States3 47.95 June7.56.4×
Iowa CityIowa, United States5 40.54 June6.46.3×
OregonOhio, United States5 49.26 June7.86.3×
HaverhillMassachusetts, United States1 31.48 June5.06.3×
LynnMassachusetts, United States1 33.98 June5.46.3×
QuincyMassachusetts, United States1 31.78 June5.16.2×
AltoonaPennsylvania, United States2 34.68 June5.66.2×
PerrysburgOhio, United States4 45.56 June7.46.1×
ChampaignIllinois, United States2 33.812 June5.56.1×
PeoriaIllinois, United States3 43.05 June7.06.1×
YoungstownOhio, United States1 42.97 June7.06.1×
WaukeshaWisconsin, United States4 38.64 June6.36.1×
JenisonMichigan, United States3 40.45 June6.66.1×
PortageIndiana, United States3 44.05 June7.26.1×
MilwaukeeWisconsin, United States4 45.65 June7.56.1×
HermitagePennsylvania, United States1 37.67 June6.26.1×
St. CatharinesOntario, Canada3 39.06 June6.56.0×
KalamazooMichigan, United States4 47.46 June7.96.0×
LowellMassachusetts, United States1 33.58 June5.66.0×
Grand RapidsMichigan, United States3 45.45 June7.66.0×
UticaNew York, United States1 29.68 June4.55.9×
MolineIllinois, United States3 32.16 June5.55.8×
BostonMassachusetts, United States2 34.18 June5.95.8×
RutlandVermont, United States2 31.28 June5.45.8×
ToledoOhio, United States4 44.16 June7.75.7×
PortsmouthNew Hampshire, United States1 32.58 June5.75.7×
FraminghamMassachusetts, United States2 28.38 June4.45.7×
DerryNew Hampshire, United States1 28.18 June4.85.6×
ColumbiaMissouri, United States1 35.410 June6.35.6×
GaryIndiana, United States3 46.05 June8.25.6×
WichitaKansas, United States1 42.611 June7.65.6×
PortsmouthOhio, United States2 40.64 June7.35.6×
WarrenOhio, United States1 46.77 June8.45.6×
PainesvilleOhio, United States2 33.07 June6.15.4×
Shaker HeightsOhio, United States1 33.57 June6.25.4×
WorcesterMassachusetts, United States2 28.88 June5.45.3×
DavenportIowa, United States3 32.36 June6.15.3×
North ChicopeeMassachusetts, United States1 26.48 June4.85.3×
WeirtonWest Virginia, United States2 32.27 June6.15.3×
South BendIndiana, United States3 37.47 June7.15.3×
RedfordMichigan, United States3 51.06 June9.75.3×
AlbanyNew York, United States2 33.18 June6.35.3×
PortlandMaine, United States2 29.88 June5.75.2×
KeeneNew Hampshire, United States1 26.68 June5.15.2×
GreenfieldMassachusetts, United States2 27.08 June5.25.2×
BrookfieldIllinois, United States1 34.05 June6.65.2×
EriePennsylvania, United States2 32.87 June6.45.1×
Fort WayneIndiana, United States2 33.77 June6.65.1×
Upper AltonIllinois, United States1 31.17 June6.15.1×
GahannaOhio, United States3 26.57 June5.25.1×
MilfordMassachusetts, United States1 25.49 June4.35.1×
HollandMichigan, United States3 37.05 June7.35.1×
BarrieOntario, Canada4 38.06 June7.55.1×
SpringfieldIllinois, United States2 36.46 June7.25.1×
AkronOhio, United States1 37.47 June7.45.1×
State CollegePennsylvania, United States2 30.18 June6.05.0×
CantonOhio, United States1 43.47 June8.75.0×
MedinaOhio, United States1 31.87 June6.54.9×
Bay CityMichigan, United States3 34.25 June7.04.9×
RockfordIllinois, United States4 32.65 June6.74.9×
Cleveland HeightsOhio, United States1 28.27 June5.84.9×
TopekaKansas, United States1 33.04 June6.84.9×
MuncieIndiana, United States2 29.17 June6.04.9×
HuntingtonWest Virginia, United States1 31.34 June6.54.8×
OlatheKansas, United States1 32.14 June6.74.8×
AugustaMaine, United States1 25.88 June5.44.8×
ClintonIowa, United States3 29.66 June6.34.7×
LafayetteIndiana, United States1 32.27 June6.94.7×
WestervilleOhio, United States3 34.67 June7.54.6×
BuffaloNew York, United States2 34.48 June7.54.6×
ColumbusOhio, United States4 33.54 June7.64.4×
Weirton HeightsWest Virginia, United States2 28.18 June6.44.4×
DecaturIllinois, United States2 31.66 June7.24.4×
FlintMichigan, United States3 30.78 June7.04.4×
WaterlooIowa, United States2 32.84 June7.64.3×
DublinOhio, United States3 29.77 June6.94.3×
DerbyKansas, United States1 30.04 June7.04.3×
WilkinsburgPennsylvania, United States1 28.95 June7.04.1×
Kansas CityKansas, United States1 30.14 June7.34.1×
SpringfieldMassachusetts, United States1 25.58 June6.24.1×
AndersonIndiana, United States1 25.812 June6.34.1×
MuscatineIowa, United States1 26.06 June6.44.1×
AshlandKentucky, United States1 29.94 June7.44.0×
SteubenvilleOhio, United States4 33.57 June8.34.0×
KokomoIndiana, United States1 27.97 June7.04.0×
Des MoinesIowa, United States3 28.27 June7.23.9×
PittsburghPennsylvania, United States3 30.18 June7.83.9×
WheelingWest Virginia, United States2 31.412 June8.33.8×
WyomingMichigan, United States3 38.25 June10.13.8×
LimaOhio, United States2 32.27 June8.83.7×
East Saint LouisIllinois, United States1 28.87 June8.13.6×
ScrantonPennsylvania, United States1 25.68 June7.23.6×
ClevelandOhio, United States4 31.97 June9.23.5×
DaytonOhio, United States1 26.24 June7.93.3×
ElkhartIndiana, United States1 25.26 June7.63.3×
AnkenyIowa, United States2 26.37 June8.03.3×
SpringfieldOhio, United States2 26.07 June8.03.3×
LouisvilleKentucky, United States1 25.04 June7.73.2×
Granite CityIllinois, United States1 28.37 June8.83.2×
CincinnatiOhio, United States1 25.34 June8.03.2×
NorwoodOhio, United States1 26.44 June8.53.1×
West MifflinPennsylvania, United States3 29.45 June9.63.1×
MiddletownOhio, United States1 28.14 June9.43.0×
St. LouisMissouri, United States1 26.27 June9.92.6×

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 6 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, June 2025: 196 cities with PM2.5 at twice their usual or more, 3 to 9 June 2025, smogrank.com/episodes/2025-06-north-eastern-united-states-and-canada (accessed 2 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.