SmogRank / Episodes / United States

North-eastern United States and Canada, 3 to 9 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 June114 cities counted
Furthest above usual19×Duluth

Day by day

7 June 114 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. LouisMiddletownNorwoodWest MifflinLouisvilleCincinnatiGranite CityElkhartSpringfieldDaytonAnkenyWheelingClevelandScrantonEast Saint LouisLimaWichitaWyomingDes MoinesPittsburghAndersonKokomoAshlandSteubenvilleSpringfieldColumbiaMuscatineWilkinsburgKansas CityDublinDerbyWaterlooWeirton HeightsFlintDecaturColumbusBuffaloWestervilleClintonLafayetteAugustaHuntingtonOlatheCleveland HeightsMuncieMedinaRockfordTopekaBay CityState CollegeCantonMilfordGahannaUpper AltonErieFort WayneSpringfieldHollandAkronBarrieKeeneGreenfieldPortlandBrookfieldNorth ChicopeeWorcesterWeirtonDavenportAlbanySouth BendRedfordPainesvilleShaker HeightsDerryPortsmouthGaryWarrenFraminghamChampaignPortsmouthToledoRutlandMolineBostonUticaLowellSt. CatharinesGrand RapidsKalamazooHermitageWaukeshaJenisonYoungstownPeoriaPortagePerrysburgMilwaukeeQuincyAltoonaHaverhillLynnIowa CityOregonSouth MilwaukeeJolietNapervilleLansingDetroitCaryDearbornDrummondvilleOak LawnSherbrookeNorth BayBloomingtonNorthbrookSt. ThomasCalumet CityBridgeviewSyracuseHamiltonGreater SudburyFranklin ParkMarquetteAllistonEast ChicagoChathamRochesterLincoln ParkHammondChicagoDes PlainesGranbyZionTaylorDoltonWindsorBrantfordSorel-TracySaint-Jean-sur-RichelieuAuroraYpsilantiWaterdownPort HuronKitchenerNewmarketCedar RapidsElginMichigan CityRochesterRouyn-NorandaMadisonBrossardTrois-RivièresSarniaLondonEastpointeEdmundstonShawiniganElmwood ParkBramptonTorontoSaint CloudGuelphSault Ste. MarieMississaugaOakvilleSouthfieldRivière-des-Prairies–Pointe-aux-TremblesMiltonSaguenayMontréalAppletonGreen BayDorvalKingstonQuébecEau 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

DuluthDuluth, 31 May: 12.8 µg/m³Duluth, 1 June: 8.0 µg/m³Duluth, 2 June: 17.0 µg/m³Duluth, 3 June: 96.0 µg/m³, 19× its usual 4.7Duluth, 4 June: 19.1 µg/m³Duluth, 5 June: 16.0 µg/m³Duluth, 6 June: 14.6 µg/m³Duluth, 7 June: 24.2 µg/m³Duluth, 8 June: 36.4 µg/m³Duluth, 9 June: 14.7 µg/m³Duluth, 10 June: 30.6 µg/m³Duluth, 11 June: 51.3 µg/m³Duluth, 12 June: 6.9 µg/m³BlaineBlaine, 31 May: 14.0 µg/m³Blaine, 1 June: 18.1 µg/m³Blaine, 2 June: 12.7 µg/m³Blaine, 3 June: 90.5 µg/m³, 17× its usual 5.2Blaine, 4 June: 25.6 µg/m³, 5.0× its usual 5.1Blaine, 5 June: 14.9 µg/m³Blaine, 6 June: 9.8 µg/m³Blaine, 7 June: 15.8 µg/m³Blaine, 8 June: 15.2 µg/m³Blaine, 9 June: 12.3 µg/m³Blaine, 10 June: 30.6 µg/m³Blaine, 11 June: 32.7 µg/m³Blaine, 12 June: 40.3 µg/m³MinneapolisMinneapolis, 31 May: 15.8 µg/m³Minneapolis, 1 June: 20.2 µg/m³Minneapolis, 2 June: 13.7 µg/m³Minneapolis, 3 June: 90.2 µg/m³, 14× its usual 6.4Minneapolis, 4 June: 28.9 µg/m³, 4.6× its usual 6.3Minneapolis, 5 June: 17.7 µg/m³Minneapolis, 6 June: 11.8 µg/m³Minneapolis, 7 June: 18.3 µg/m³Minneapolis, 8 June: 16.3 µg/m³Minneapolis, 9 June: 13.0 µg/m³Minneapolis, 10 June: 31.1 µg/m³Minneapolis, 11 June: 34.3 µg/m³Minneapolis, 12 June: 43.7 µg/m³SuperiorSuperior, 31 May: 20.2 µg/m³Superior, 1 June: 8.2 µg/m³Superior, 2 June: 11.9 µg/m³Superior, 3 June: 88.7 µg/m³, 16× its usual 5.5Superior, 4 June: 19.2 µg/m³Superior, 5 June: 13.4 µg/m³Superior, 6 June: 12.2 µg/m³Superior, 7 June: 18.9 µg/m³Superior, 8 June: 27.9 µg/m³Superior, 9 June: 11.2 µg/m³Superior, 10 June: 24.7 µg/m³Superior, 11 June: 40.6 µg/m³Superior, 12 June: 6.6 µg/m³MankatoMankato, 31 May: 14.3 µg/m³Mankato, 1 June: 21.0 µg/m³Mankato, 2 June: 11.3 µg/m³Mankato, 3 June: 85.0 µg/m³, 15× its usual 5.7Mankato, 4 June: 21.8 µg/m³Mankato, 5 June: 14.4 µg/m³Mankato, 6 June: 16.1 µg/m³Mankato, 7 June: 18.7 µg/m³Mankato, 8 June: 16.2 µg/m³Mankato, 9 June: 12.9 µg/m³Mankato, 10 June: 23.5 µg/m³Mankato, 11 June: 35.8 µg/m³Mankato, 12 June: 40.6 µg/m³ShakopeeShakopee, 31 May: 14.1 µg/m³Shakopee, 1 June: 24.2 µg/m³Shakopee, 2 June: 11.3 µg/m³Shakopee, 3 June: 84.2 µg/m³, 14× its usual 6.0Shakopee, 4 June: 24.7 µg/m³Shakopee, 5 June: 13.5 µg/m³Shakopee, 6 June: 11.3 µg/m³Shakopee, 7 June: 17.0 µg/m³Shakopee, 8 June: 15.2 µg/m³Shakopee, 9 June: 11.4 µg/m³Shakopee, 10 June: 27.4 µg/m³Shakopee, 11 June: 33.5 µg/m³Shakopee, 12 June: 43.8 µg/m³Saint MichaelSaint Michael, 31 May: 13.6 µg/m³Saint Michael, 1 June: 23.2 µg/m³Saint Michael, 2 June: 12.5 µg/m³Saint Michael, 3 June: 81.2 µg/m³, 15× its usual 5.6Saint Michael, 4 June: 19.0 µg/m³Saint Michael, 5 June: 12.7 µg/m³Saint Michael, 6 June: 10.0 µg/m³Saint Michael, 7 June: 13.5 µg/m³Saint Michael, 8 June: 13.3 µg/m³Saint Michael, 9 June: 12.3 µg/m³Saint Michael, 10 June: 28.9 µg/m³Saint Michael, 11 June: 27.4 µg/m³Saint Michael, 12 June: 39.4 µg/m³Saint PaulSaint Paul, 31 May: 14.8 µg/m³Saint Paul, 1 June: 16.4 µg/m³Saint Paul, 2 June: 12.3 µg/m³Saint Paul, 3 June: 80.9 µg/m³, 13× its usual 6.1Saint Paul, 4 June: 28.9 µg/m³, 4.8× its usual 6.0Saint Paul, 5 June: 16.3 µg/m³Saint Paul, 6 June: 10.8 µg/m³Saint Paul, 7 June: 18.5 µg/m³Saint Paul, 8 June: 15.4 µg/m³Saint Paul, 9 June: 11.2 µg/m³Saint Paul, 10 June: 28.7 µg/m³Saint Paul, 11 June: 31.3 µg/m³Saint Paul, 12 June: 38.4 µg/m³BurnsvilleBurnsville, 31 May: 14.1 µg/m³Burnsville, 1 June: 20.8 µg/m³Burnsville, 2 June: 11.4 µg/m³Burnsville, 3 June: 79.7 µg/m³, 12× its usual 6.4Burnsville, 4 June: 23.9 µg/m³Burnsville, 5 June: 12.9 µg/m³Burnsville, 6 June: 12.8 µg/m³Burnsville, 7 June: 20.4 µg/m³Burnsville, 8 June: 16.3 µg/m³Burnsville, 9 June: 11.1 µg/m³Burnsville, 10 June: 27.6 µg/m³Burnsville, 11 June: 35.2 µg/m³Burnsville, 12 June: 44.8 µg/m³Apple ValleyApple Valley, 31 May: 13.9 µg/m³Apple Valley, 1 June: 20.0 µg/m³Apple Valley, 2 June: 11.8 µg/m³Apple Valley, 3 June: 78.3 µg/m³, 14× its usual 5.7Apple Valley, 4 June: 25.7 µg/m³, 4.8× its usual 5.4Apple Valley, 5 June: 13.1 µg/m³Apple Valley, 6 June: 14.1 µg/m³Apple Valley, 7 June: 20.0 µg/m³Apple Valley, 8 June: 16.9 µg/m³Apple Valley, 9 June: 12.0 µg/m³Apple Valley, 10 June: 27.2 µg/m³Apple Valley, 11 June: 35.3 µg/m³Apple Valley, 12 June: 46.1 µg/m³Eau ClaireEau Claire, 31 May: 11.7 µg/m³Eau Claire, 1 June: 8.1 µg/m³Eau Claire, 2 June: 14.7 µg/m³Eau Claire, 3 June: 63.2 µg/m³, 11× its usual 5.5Eau Claire, 4 June: 40.5 µg/m³, 7.4× its usual 5.5Eau Claire, 5 June: 14.0 µg/m³Eau Claire, 6 June: 14.3 µg/m³Eau Claire, 7 June: 19.5 µg/m³Eau Claire, 8 June: 22.5 µg/m³Eau Claire, 9 June: 9.6 µg/m³Eau Claire, 10 June: 30.8 µg/m³Eau Claire, 11 June: 34.8 µg/m³Eau Claire, 12 June: 41.5 µg/m³RochesterRochester, 31 May: 16.5 µg/m³Rochester, 1 June: 18.3 µg/m³Rochester, 2 June: 13.9 µg/m³Rochester, 3 June: 61.9 µg/m³, 8.8× its usual 7.0Rochester, 4 June: 36.7 µg/m³, 5.3× its usual 6.9Rochester, 5 June: 14.8 µg/m³Rochester, 6 June: 16.3 µg/m³Rochester, 7 June: 25.0 µg/m³, 3.8× its usual 6.6Rochester, 8 June: 21.6 µg/m³Rochester, 9 June: 10.5 µg/m³Rochester, 10 June: 25.3 µg/m³Rochester, 11 June: 34.2 µg/m³Rochester, 12 June: 42.0 µg/m³Saint CloudSaint Cloud, 31 May: 13.7 µg/m³Saint Cloud, 1 June: 22.0 µg/m³Saint Cloud, 2 June: 14.3 µg/m³Saint Cloud, 3 June: 54.7 µg/m³, 9.9× its usual 5.5Saint Cloud, 4 June: 13.5 µg/m³Saint Cloud, 5 June: 11.3 µg/m³Saint Cloud, 6 June: 8.5 µg/m³Saint Cloud, 7 June: 9.7 µg/m³Saint Cloud, 8 June: 11.2 µg/m³Saint Cloud, 9 June: 12.5 µg/m³Saint Cloud, 10 June: 26.4 µg/m³Saint Cloud, 11 June: 29.1 µg/m³Saint Cloud, 12 June: 27.7 µg/m³OconomowocOconomowoc, 31 May: 8.1 µg/m³Oconomowoc, 1 June: no readingOconomowoc, 2 June: no readingOconomowoc, 3 June: 18.5 µg/m³Oconomowoc, 4 June: 71.9 µg/m³, 14× its usual 4.5Oconomowoc, 5 June: 44.2 µg/m³, 8.8× its usual 4.8Oconomowoc, 6 June: 35.7 µg/m³, 7.1× its usual 4.8Oconomowoc, 7 June: 36.8 µg/m³, 6.8× its usual 5.4Oconomowoc, 8 June: 36.5 µg/m³, 6.8× its usual 5.4Oconomowoc, 9 June: 24.4 µg/m³Oconomowoc, 10 June: 32.2 µg/m³Oconomowoc, 11 June: 38.2 µg/m³Oconomowoc, 12 June: 41.8 µg/m³WindsorWindsor, 31 May: 7.4 µg/m³Windsor, 1 June: 6.0 µg/m³Windsor, 2 June: 7.0 µg/m³Windsor, 3 June: 16.0 µg/m³Windsor, 4 June: 26.2 µg/m³, 3.6× its usual 7.3Windsor, 5 June: 45.5 µg/m³, 6.1× its usual 7.4Windsor, 6 June: 61.3 µg/m³, 8.2× its usual 7.5Windsor, 7 June: 24.3 µg/m³Windsor, 8 June: 43.1 µg/m³, 5.9× its usual 7.3Windsor, 9 June: 25.7 µg/m³Windsor, 10 June: 15.7 µg/m³Windsor, 11 June: 25.0 µg/m³Windsor, 12 June: 27.4 µg/m³Green BayGreen Bay, 31 May: 5.1 µg/m³Green Bay, 1 June: 6.0 µg/m³Green Bay, 2 June: 10.1 µg/m³Green Bay, 3 June: 19.2 µg/m³Green Bay, 4 June: 60.8 µg/m³, 11× its usual 5.5Green Bay, 5 June: 34.5 µg/m³, 6.3× its usual 5.5Green Bay, 6 June: 23.6 µg/m³Green Bay, 7 June: 19.8 µg/m³Green Bay, 8 June: 20.8 µg/m³Green Bay, 9 June: 10.3 µg/m³Green Bay, 10 June: 18.3 µg/m³Green Bay, 11 June: 34.9 µg/m³Green Bay, 12 June: 24.4 µg/m³DoltonDolton, 31 May: 8.5 µg/m³Dolton, 1 June: 8.7 µg/m³Dolton, 2 June: 11.5 µg/m³Dolton, 3 June: 18.3 µg/m³Dolton, 4 June: 41.8 µg/m³, 5.5× its usual 7.6Dolton, 5 June: 60.1 µg/m³, 7.9× its usual 7.6Dolton, 6 June: 37.4 µg/m³, 4.9× its usual 7.7Dolton, 7 June: 24.4 µg/m³Dolton, 8 June: 26.1 µg/m³, 3.4× its usual 7.7Dolton, 9 June: 22.3 µg/m³Dolton, 10 June: 21.1 µg/m³Dolton, 11 June: 26.3 µg/m³Dolton, 12 June: 29.1 µg/m³Elmwood ParkElmwood Park, 31 May: 8.8 µg/m³Elmwood Park, 1 June: 7.1 µg/m³Elmwood Park, 2 June: 11.3 µg/m³Elmwood Park, 3 June: 16.2 µg/m³Elmwood Park, 4 June: 25.5 µg/m³, 4.0× its usual 6.3Elmwood Park, 5 June: 59.7 µg/m³, 9.6× its usual 6.2Elmwood Park, 6 June: 35.5 µg/m³, 5.8× its usual 6.1Elmwood Park, 7 June: 27.2 µg/m³, 4.7× its usual 5.8Elmwood Park, 8 June: 27.0 µg/m³, 4.4× its usual 6.1Elmwood Park, 9 June: 19.4 µg/m³Elmwood Park, 10 June: 19.7 µg/m³Elmwood Park, 11 June: 24.7 µg/m³Elmwood Park, 12 June: 26.8 µg/m³AppletonAppleton, 31 May: 6.0 µg/m³Appleton, 1 June: 6.5 µg/m³Appleton, 2 June: 10.5 µg/m³Appleton, 3 June: 20.4 µg/m³Appleton, 4 June: 59.0 µg/m³, 11× its usual 5.4Appleton, 5 June: 30.5 µg/m³, 5.5× its usual 5.5Appleton, 6 June: 23.8 µg/m³Appleton, 7 June: 18.8 µg/m³Appleton, 8 June: 24.8 µg/m³Appleton, 9 June: 10.1 µg/m³Appleton, 10 June: 21.3 µg/m³Appleton, 11 June: 31.9 µg/m³Appleton, 12 June: 31.3 µg/m³HammondHammond, 31 May: 9.0 µg/m³Hammond, 1 June: 9.2 µg/m³Hammond, 2 June: 9.8 µg/m³Hammond, 3 June: 15.5 µg/m³Hammond, 4 June: 35.0 µg/m³, 4.5× its usual 7.7Hammond, 5 June: 58.3 µg/m³, 7.7× its usual 7.6Hammond, 6 June: 40.5 µg/m³, 5.3× its usual 7.6Hammond, 7 June: 28.1 µg/m³, 3.7× its usual 7.5Hammond, 8 June: 25.5 µg/m³, 3.4× its usual 7.6Hammond, 9 June: 21.5 µg/m³Hammond, 10 June: 17.0 µg/m³Hammond, 11 June: 21.7 µg/m³Hammond, 12 June: 30.4 µg/m³SarniaSarnia, 31 May: 3.7 µg/m³Sarnia, 1 June: 4.1 µg/m³Sarnia, 2 June: 5.8 µg/m³Sarnia, 3 June: 14.8 µg/m³Sarnia, 4 June: 33.3 µg/m³, 5.3× its usual 6.3Sarnia, 5 June: 57.6 µg/m³, 9.0× its usual 6.4Sarnia, 6 June: 29.4 µg/m³, 4.5× its usual 6.5Sarnia, 7 June: 28.4 µg/m³, 4.4× its usual 6.5Sarnia, 8 June: 35.4 µg/m³, 5.4× its usual 6.5Sarnia, 9 June: 25.8 µg/m³Sarnia, 10 June: 13.0 µg/m³Sarnia, 11 June: 24.1 µg/m³Sarnia, 12 June: 24.3 µg/m³DearbornDearborn, 31 May: 6.9 µg/m³Dearborn, 1 June: 4.5 µg/m³Dearborn, 2 June: 6.9 µg/m³Dearborn, 3 June: 17.0 µg/m³Dearborn, 4 June: 25.0 µg/m³, 3.0× its usual 8.4Dearborn, 5 June: 44.2 µg/m³, 5.3× its usual 8.4Dearborn, 6 June: 56.0 µg/m³, 6.6× its usual 8.5Dearborn, 7 June: 21.3 µg/m³Dearborn, 8 June: 38.3 µg/m³, 4.6× its usual 8.4Dearborn, 9 June: 23.7 µg/m³Dearborn, 10 June: 15.1 µg/m³Dearborn, 11 June: 23.9 µg/m³Dearborn, 12 June: 23.6 µg/m³Des PlainesDes Plaines, 31 May: 9.6 µg/m³Des Plaines, 1 June: 7.3 µg/m³Des Plaines, 2 June: 10.3 µg/m³Des Plaines, 3 June: 15.3 µg/m³Des Plaines, 4 June: 25.7 µg/m³, 3.6× its usual 7.1Des Plaines, 5 June: 55.5 µg/m³, 7.8× its usual 7.1Des Plaines, 6 June: 33.9 µg/m³, 4.8× its usual 7.1Des Plaines, 7 June: 29.2 µg/m³, 4.1× its usual 7.1Des Plaines, 8 June: 25.9 µg/m³, 3.6× its usual 7.1Des Plaines, 9 June: 19.2 µg/m³Des Plaines, 10 June: 19.5 µg/m³Des Plaines, 11 June: 24.7 µg/m³Des Plaines, 12 June: 27.9 µg/m³Sault Ste. MarieSault Ste. Marie, 31 May: 2.3 µg/m³Sault Ste. Marie, 1 June: no readingSault Ste. Marie, 2 June: 5.5 µg/m³Sault Ste. Marie, 3 June: 10.5 µg/m³Sault Ste. Marie, 4 June: 47.6 µg/m³, 9.3× its usual 5.1Sault Ste. Marie, 5 June: 26.7 µg/m³, 5.1× its usual 5.2Sault Ste. Marie, 6 June: 21.7 µg/m³Sault Ste. Marie, 7 June: 54.5 µg/m³, 10× its usual 5.4Sault Ste. Marie, 8 June: 36.3 µg/m³, 6.6× its usual 5.5Sault Ste. Marie, 9 June: 18.0 µg/m³Sault Ste. Marie, 10 June: 9.5 µg/m³Sault Ste. Marie, 11 June: 17.2 µg/m³Sault Ste. Marie, 12 June: 9.4 µg/m³East ChicagoEast Chicago, 31 May: 8.8 µg/m³East Chicago, 1 June: 5.7 µg/m³East Chicago, 2 June: 9.2 µg/m³East Chicago, 3 June: 14.6 µg/m³East Chicago, 4 June: 38.7 µg/m³, 5.3× its usual 7.3East Chicago, 5 June: 54.4 µg/m³, 7.5× its usual 7.3East Chicago, 6 June: 34.5 µg/m³, 4.7× its usual 7.3East Chicago, 7 June: 22.7 µg/m³East Chicago, 8 June: 21.6 µg/m³East Chicago, 9 June: 18.5 µg/m³East Chicago, 10 June: 16.7 µg/m³East Chicago, 11 June: 20.9 µg/m³East Chicago, 12 June: 25.9 µg/m³Calumet CityCalumet City, 31 May: 9.2 µg/m³Calumet City, 1 June: 9.2 µg/m³Calumet City, 2 June: 10.2 µg/m³Calumet City, 3 June: 15.5 µg/m³Calumet City, 4 June: 28.2 µg/m³, 3.7× its usual 7.7Calumet City, 5 June: 54.1 µg/m³, 7.0× its usual 7.7Calumet City, 6 June: 35.8 µg/m³, 4.6× its usual 7.7Calumet City, 7 June: 25.0 µg/m³, 3.2× its usual 7.7Calumet City, 8 June: 24.2 µg/m³Calumet City, 9 June: 19.0 µg/m³Calumet City, 10 June: 16.7 µg/m³Calumet City, 11 June: 21.2 µg/m³Calumet City, 12 June: 26.8 µg/m³Port HuronPort Huron, 31 May: 4.0 µg/m³Port Huron, 1 June: 4.6 µg/m³Port Huron, 2 June: 5.3 µg/m³Port Huron, 3 June: 14.6 µg/m³Port Huron, 4 June: 31.1 µg/m³, 4.9× its usual 6.3Port Huron, 5 June: 53.9 µg/m³, 8.6× its usual 6.3Port Huron, 6 June: 31.1 µg/m³, 4.7× its usual 6.6Port Huron, 7 June: 28.3 µg/m³, 4.3× its usual 6.6Port Huron, 8 June: 36.2 µg/m³, 5.3× its usual 6.8Port Huron, 9 June: 25.2 µg/m³Port Huron, 10 June: 12.6 µg/m³Port Huron, 11 June: 22.6 µg/m³Port Huron, 12 June: 22.8 µg/m³NepeanNepean, 31 May: 5.9 µg/m³Nepean, 1 June: no readingNepean, 2 June: no readingNepean, 3 June: 7.6 µg/m³Nepean, 4 June: 28.0 µg/m³Nepean, 5 June: 50.2 µg/m³, 6.8× its usual 7.4Nepean, 6 June: 116.0 µg/m³, 16× its usual 7.4Nepean, 7 June: 65.3 µg/m³, 8.5× its usual 7.7Nepean, 8 June: 34.7 µg/m³, 4.8× its usual 7.3Nepean, 9 June: 33.2 µg/m³, 4.5× its usual 7.4Nepean, 10 June: 12.9 µg/m³Nepean, 11 June: 28.1 µg/m³Nepean, 12 June: 22.8 µg/m³OttawaOttawa, 31 May: 4.0 µg/m³Ottawa, 1 June: 1.4 µg/m³Ottawa, 2 June: 3.4 µg/m³Ottawa, 3 June: 6.4 µg/m³Ottawa, 4 June: 15.5 µg/m³Ottawa, 5 June: 32.1 µg/m³, 5.8× its usual 5.5Ottawa, 6 June: 89.6 µg/m³, 16× its usual 5.5Ottawa, 7 June: 46.8 µg/m³, 8.5× its usual 5.5Ottawa, 8 June: 20.1 µg/m³Ottawa, 9 June: 20.5 µg/m³Ottawa, 10 June: 7.4 µg/m³Ottawa, 11 June: 13.2 µg/m³Ottawa, 12 June: 11.0 µg/m³L'Ancienne-LoretteL'Ancienne-Lorette, 31 May: 5.4 µg/m³L'Ancienne-Lorette, 1 June: 1.7 µg/m³L'Ancienne-Lorette, 2 June: 3.8 µg/m³L'Ancienne-Lorette, 3 June: 5.8 µg/m³L'Ancienne-Lorette, 4 June: 14.5 µg/m³L'Ancienne-Lorette, 5 June: 26.2 µg/m³, 4.2× its usual 6.3L'Ancienne-Lorette, 6 June: 73.3 µg/m³, 12× its usual 6.1L'Ancienne-Lorette, 7 June: 50.2 µg/m³, 8.2× its usual 6.1L'Ancienne-Lorette, 8 June: 10.5 µg/m³L'Ancienne-Lorette, 9 June: 14.0 µg/m³L'Ancienne-Lorette, 10 June: 13.7 µg/m³L'Ancienne-Lorette, 11 June: 13.1 µg/m³L'Ancienne-Lorette, 12 June: 10.0 µg/m³CornwallCornwall, 31 May: 4.7 µg/m³Cornwall, 1 June: 1.8 µg/m³Cornwall, 2 June: 3.7 µg/m³Cornwall, 3 June: 6.8 µg/m³Cornwall, 4 June: 16.8 µg/m³Cornwall, 5 June: 25.1 µg/m³, 4.4× its usual 5.7Cornwall, 6 June: 70.3 µg/m³, 12× its usual 5.7Cornwall, 7 June: 48.8 µg/m³, 8.6× its usual 5.7Cornwall, 8 June: 29.3 µg/m³, 5.1× its usual 5.7Cornwall, 9 June: 19.7 µg/m³Cornwall, 10 June: 7.2 µg/m³Cornwall, 11 June: 14.5 µg/m³Cornwall, 12 June: 16.7 µg/m³TorontoToronto, 31 May: 5.8 µg/m³Toronto, 1 June: 3.0 µg/m³Toronto, 2 June: 5.9 µg/m³Toronto, 3 June: 10.5 µg/m³Toronto, 4 June: 20.2 µg/m³Toronto, 5 June: 29.6 µg/m³, 4.4× its usual 6.8Toronto, 6 June: 67.9 µg/m³, 9.8× its usual 6.9Toronto, 7 June: 31.4 µg/m³, 4.6× its usual 6.8Toronto, 8 June: 37.8 µg/m³, 5.5× its usual 6.9Toronto, 9 June: 21.3 µg/m³Toronto, 10 June: 10.8 µg/m³Toronto, 11 June: 21.5 µg/m³Toronto, 12 June: 18.4 µg/m³SaguenaySaguenay, 31 May: 7.0 µg/m³Saguenay, 1 June: 1.9 µg/m³Saguenay, 2 June: 2.8 µg/m³Saguenay, 3 June: 7.0 µg/m³Saguenay, 4 June: 15.8 µg/m³Saguenay, 5 June: 41.6 µg/m³, 7.1× its usual 5.9Saguenay, 6 June: 66.9 µg/m³, 11× its usual 6.2Saguenay, 7 June: 27.6 µg/m³, 4.4× its usual 6.3Saguenay, 8 June: 8.9 µg/m³Saguenay, 9 June: 15.2 µg/m³Saguenay, 10 June: 16.1 µg/m³Saguenay, 11 June: 11.8 µg/m³Saguenay, 12 June: 6.4 µg/m³PeterboroughPeterborough, 31 May: 3.1 µg/m³Peterborough, 1 June: 2.1 µg/m³Peterborough, 2 June: 3.3 µg/m³Peterborough, 3 June: 8.0 µg/m³Peterborough, 4 June: 15.7 µg/m³Peterborough, 5 June: 30.8 µg/m³, 5.8× its usual 5.3Peterborough, 6 June: 66.2 µg/m³, 12× its usual 5.4Peterborough, 7 June: 39.5 µg/m³, 7.5× its usual 5.3Peterborough, 8 June: 32.1 µg/m³, 6.1× its usual 5.3Peterborough, 9 June: 11.8 µg/m³Peterborough, 10 June: 8.1 µg/m³Peterborough, 11 June: 15.9 µg/m³Peterborough, 12 June: 16.1 µg/m³KitchenerKitchener, 31 May: 4.7 µg/m³Kitchener, 1 June: 3.0 µg/m³Kitchener, 2 June: 4.4 µg/m³Kitchener, 3 June: 10.1 µg/m³Kitchener, 4 June: 17.7 µg/m³Kitchener, 5 June: 44.7 µg/m³, 6.0× its usual 7.4Kitchener, 6 June: 63.9 µg/m³, 8.6× its usual 7.4Kitchener, 7 June: 24.4 µg/m³Kitchener, 8 June: 37.0 µg/m³, 5.0× its usual 7.4Kitchener, 9 June: 21.5 µg/m³Kitchener, 10 June: 10.8 µg/m³Kitchener, 11 June: 22.0 µg/m³Kitchener, 12 June: 18.2 µg/m³MiltonMilton, 31 May: 5.1 µg/m³Milton, 1 June: 3.0 µg/m³Milton, 2 June: 4.3 µg/m³Milton, 3 June: 10.5 µg/m³Milton, 4 June: 20.0 µg/m³Milton, 5 June: 38.0 µg/m³, 6.6× its usual 5.8Milton, 6 June: 62.8 µg/m³, 11× its usual 5.9Milton, 7 June: 28.7 µg/m³, 4.9× its usual 5.9Milton, 8 June: 37.1 µg/m³, 6.3× its usual 5.9Milton, 9 June: 23.2 µg/m³Milton, 10 June: 10.6 µg/m³Milton, 11 June: 22.0 µg/m³Milton, 12 June: 17.5 µg/m³Franklin ParkFranklin Park, 31 May: 9.4 µg/m³Franklin Park, 1 June: 8.6 µg/m³Franklin Park, 2 June: 10.6 µg/m³Franklin Park, 3 June: 16.2 µg/m³Franklin Park, 4 June: 23.7 µg/m³Franklin Park, 5 June: 59.5 µg/m³, 7.3× its usual 8.1Franklin Park, 6 June: 35.6 µg/m³, 4.2× its usual 8.4Franklin Park, 7 June: 32.3 µg/m³, 3.9× its usual 8.3Franklin Park, 8 June: 27.6 µg/m³, 3.3× its usual 8.4Franklin Park, 9 June: 20.4 µg/m³Franklin Park, 10 June: 20.9 µg/m³Franklin Park, 11 June: 26.3 µg/m³Franklin Park, 12 June: 30.3 µg/m³ChicagoChicago, 31 May: 8.1 µg/m³Chicago, 1 June: 7.7 µg/m³Chicago, 2 June: 9.7 µg/m³Chicago, 3 June: 15.8 µg/m³Chicago, 4 June: 20.8 µg/m³Chicago, 5 June: 58.4 µg/m³, 7.7× its usual 7.6Chicago, 6 June: 35.2 µg/m³, 4.5× its usual 7.9Chicago, 7 June: 26.3 µg/m³, 3.3× its usual 7.9Chicago, 8 June: 27.2 µg/m³, 3.4× its usual 8.0Chicago, 9 June: 18.7 µg/m³Chicago, 10 June: 18.1 µg/m³Chicago, 11 June: 24.2 µg/m³Chicago, 12 June: 27.8 µg/m³Lincoln ParkLincoln Park, 31 May: 6.9 µg/m³Lincoln Park, 1 June: 5.3 µg/m³Lincoln Park, 2 June: 6.5 µg/m³Lincoln Park, 3 June: 14.0 µg/m³Lincoln Park, 4 June: 21.7 µg/m³Lincoln Park, 5 June: 41.4 µg/m³, 5.5× its usual 7.5Lincoln Park, 6 June: 56.8 µg/m³, 7.6× its usual 7.5Lincoln Park, 7 June: 21.0 µg/m³Lincoln Park, 8 June: 38.6 µg/m³, 5.3× its usual 7.3Lincoln Park, 9 June: 20.7 µg/m³Lincoln Park, 10 June: 12.9 µg/m³Lincoln Park, 11 June: 20.0 µg/m³Lincoln Park, 12 June: 24.2 µg/m³SouthfieldSouthfield, 31 May: 6.5 µg/m³Southfield, 1 June: 4.4 µg/m³Southfield, 2 June: 6.4 µg/m³Southfield, 3 June: 16.0 µg/m³Southfield, 4 June: 20.0 µg/m³Southfield, 5 June: 48.7 µg/m³, 9.4× its usual 5.2Southfield, 6 June: 56.1 µg/m³, 11× its usual 5.3Southfield, 7 June: 20.7 µg/m³Southfield, 8 June: 38.5 µg/m³, 7.3× its usual 5.3Southfield, 9 June: 24.1 µg/m³Southfield, 10 June: 13.5 µg/m³Southfield, 11 June: 23.8 µg/m³Southfield, 12 June: 24.0 µg/m³YpsilantiYpsilanti, 31 May: 7.2 µg/m³Ypsilanti, 1 June: 4.5 µg/m³Ypsilanti, 2 June: 6.7 µg/m³Ypsilanti, 3 June: 15.5 µg/m³Ypsilanti, 4 June: 14.9 µg/m³Ypsilanti, 5 June: 39.6 µg/m³, 6.0× its usual 6.6Ypsilanti, 6 June: 56.0 µg/m³, 8.5× its usual 6.6Ypsilanti, 7 June: 26.4 µg/m³, 4.1× its usual 6.5Ypsilanti, 8 June: 37.8 µg/m³, 5.8× its usual 6.5Ypsilanti, 9 June: 20.8 µg/m³Ypsilanti, 10 June: 12.8 µg/m³Ypsilanti, 11 June: 19.3 µg/m³Ypsilanti, 12 June: 23.9 µg/m³DetroitDetroit, 31 May: 6.8 µg/m³Detroit, 1 June: 5.8 µg/m³Detroit, 2 June: 7.7 µg/m³Detroit, 3 June: 16.1 µg/m³Detroit, 4 June: 24.5 µg/m³Detroit, 5 June: 40.5 µg/m³, 4.8× its usual 8.5Detroit, 6 June: 55.0 µg/m³, 6.5× its usual 8.4Detroit, 7 June: 21.8 µg/m³Detroit, 8 June: 37.4 µg/m³, 4.5× its usual 8.3Detroit, 9 June: 23.0 µg/m³Detroit, 10 June: 14.7 µg/m³Detroit, 11 June: 22.2 µg/m³Detroit, 12 June: 23.3 µg/m³GuelphGuelph, 31 May: 4.3 µg/m³Guelph, 1 June: 3.1 µg/m³Guelph, 2 June: 4.6 µg/m³Guelph, 3 June: 10.2 µg/m³Guelph, 4 June: 16.7 µg/m³Guelph, 5 June: 46.0 µg/m³, 8.4× its usual 5.5Guelph, 6 June: 54.9 µg/m³, 10.0× its usual 5.5Guelph, 7 June: 24.5 µg/m³Guelph, 8 June: 35.0 µg/m³, 6.4× its usual 5.5Guelph, 9 June: 23.0 µg/m³Guelph, 10 June: 10.4 µg/m³Guelph, 11 June: 20.1 µg/m³Guelph, 12 June: 16.0 µg/m³BramptonBrampton, 31 May: 4.9 µg/m³Brampton, 1 June: 2.3 µg/m³Brampton, 2 June: 3.9 µg/m³Brampton, 3 June: 9.3 µg/m³Brampton, 4 June: 16.5 µg/m³Brampton, 5 June: 31.5 µg/m³, 5.9× its usual 5.3Brampton, 6 June: 54.6 µg/m³, 9.8× its usual 5.6Brampton, 7 June: 27.5 µg/m³, 5.2× its usual 5.3Brampton, 8 June: 33.8 µg/m³, 6.5× its usual 5.2Brampton, 9 June: 20.7 µg/m³Brampton, 10 June: 9.3 µg/m³Brampton, 11 June: 19.4 µg/m³Brampton, 12 June: 15.6 µg/m³BellevilleBelleville, 31 May: 3.9 µg/m³Belleville, 1 June: 1.7 µg/m³Belleville, 2 June: 3.5 µg/m³Belleville, 3 June: 5.8 µg/m³Belleville, 4 June: 17.4 µg/m³Belleville, 5 June: 21.4 µg/m³Belleville, 6 June: 79.5 µg/m³, 14× its usual 5.5Belleville, 7 June: 47.4 µg/m³, 8.6× its usual 5.5Belleville, 8 June: 34.0 µg/m³, 6.2× its usual 5.5Belleville, 9 June: 9.5 µg/m³Belleville, 10 June: 6.6 µg/m³Belleville, 11 June: 15.3 µg/m³Belleville, 12 June: 18.8 µg/m³Sept-ÎlesSept-Îles, 31 May: 5.9 µg/m³Sept-Îles, 1 June: 4.5 µg/m³Sept-Îles, 2 June: 5.6 µg/m³Sept-Îles, 3 June: 2.3 µg/m³Sept-Îles, 4 June: 4.9 µg/m³Sept-Îles, 5 June: 8.5 µg/m³Sept-Îles, 6 June: 78.0 µg/m³, 16× its usual 3.5Sept-Îles, 7 June: 37.2 µg/m³, 7.4× its usual 3.6Sept-Îles, 8 June: 5.3 µg/m³Sept-Îles, 9 June: 10.6 µg/m³Sept-Îles, 10 June: 13.7 µg/m³Sept-Îles, 11 June: 4.6 µg/m³Sept-Îles, 12 June: 4.8 µg/m³DorvalDorval, 31 May: 5.9 µg/m³Dorval, 1 June: 1.5 µg/m³Dorval, 2 June: 2.9 µg/m³Dorval, 3 June: 5.6 µg/m³Dorval, 4 June: 16.8 µg/m³Dorval, 5 June: 17.9 µg/m³Dorval, 6 June: 68.9 µg/m³, 11× its usual 6.2Dorval, 7 June: 52.7 µg/m³, 8.5× its usual 6.2Dorval, 8 June: 25.5 µg/m³, 4.2× its usual 6.1Dorval, 9 June: 27.7 µg/m³, 4.5× its usual 6.1Dorval, 10 June: 8.2 µg/m³Dorval, 11 June: 15.0 µg/m³Dorval, 12 June: 15.4 µg/m³MontréalMontréal, 31 May: 6.3 µg/m³Montréal, 1 June: 1.9 µg/m³Montréal, 2 June: 3.6 µg/m³Montréal, 3 June: 6.1 µg/m³Montréal, 4 June: 17.2 µg/m³Montréal, 5 June: 18.7 µg/m³Montréal, 6 June: 68.1 µg/m³, 11× its usual 6.3Montréal, 7 June: 52.1 µg/m³, 8.3× its usual 6.3Montréal, 8 June: 23.9 µg/m³Montréal, 9 June: 26.7 µg/m³, 4.2× its usual 6.3Montréal, 10 June: 8.0 µg/m³Montréal, 11 June: 15.2 µg/m³Montréal, 12 June: 16.0 µg/m³BrantfordBrantford, 31 May: 9.4 µg/m³Brantford, 1 June: 2.6 µg/m³Brantford, 2 June: 3.9 µg/m³Brantford, 3 June: 9.1 µg/m³Brantford, 4 June: 18.6 µg/m³Brantford, 5 June: 17.3 µg/m³Brantford, 6 June: 67.5 µg/m³, 8.3× its usual 8.1Brantford, 7 June: 28.8 µg/m³, 3.6× its usual 8.0Brantford, 8 June: 39.7 µg/m³, 4.7× its usual 8.4Brantford, 9 June: 20.4 µg/m³Brantford, 10 June: 8.6 µg/m³Brantford, 11 June: 19.5 µg/m³Brantford, 12 June: 21.6 µg/m³OakvilleOakville, 31 May: 5.7 µg/m³Oakville, 1 June: 2.7 µg/m³Oakville, 2 June: 3.9 µg/m³Oakville, 3 June: 9.0 µg/m³Oakville, 4 June: 18.5 µg/m³Oakville, 5 June: 19.2 µg/m³Oakville, 6 June: 63.8 µg/m³, 10× its usual 6.1Oakville, 7 June: 29.3 µg/m³, 4.9× its usual 6.0Oakville, 8 June: 36.9 µg/m³, 6.1× its usual 6.0Oakville, 9 June: 21.2 µg/m³Oakville, 10 June: 8.8 µg/m³Oakville, 11 June: 19.7 µg/m³Oakville, 12 June: 16.7 µg/m³LondonLondon, 31 May: 5.6 µg/m³London, 1 June: 3.1 µg/m³London, 2 June: 5.9 µg/m³London, 3 June: no readingLondon, 4 June: 18.2 µg/m³London, 5 June: 20.3 µg/m³London, 6 June: 63.4 µg/m³, 9.1× its usual 7.0London, 7 June: 29.0 µg/m³, 4.1× its usual 7.0London, 8 June: 37.1 µg/m³, 5.3× its usual 7.0London, 9 June: 18.1 µg/m³London, 10 June: 10.2 µg/m³London, 11 June: 21.0 µg/m³London, 12 June: 20.8 µg/m³QuébecQuébec, 31 May: 4.7 µg/m³Québec, 1 June: 1.6 µg/m³Québec, 2 June: 3.3 µg/m³Québec, 3 June: 5.8 µg/m³Québec, 4 June: 13.8 µg/m³Québec, 5 June: 19.7 µg/m³Québec, 6 June: 60.6 µg/m³, 11× its usual 5.4Québec, 7 June: 47.9 µg/m³, 8.9× its usual 5.4Québec, 8 June: 11.8 µg/m³Québec, 9 June: 13.1 µg/m³Québec, 10 June: 12.5 µg/m³Québec, 11 June: 12.4 µg/m³Québec, 12 June: 9.6 µg/m³Rivière-des-Prairie…Rivière-des-Prairies–Pointe-aux-Trembles, 31 May: 5.3 µg/m³Rivière-des-Prairies–Pointe-aux-Trembles, 1 June: 1.6 µg/m³Rivière-des-Prairies–Pointe-aux-Trembles, 2 June: 3.4 µg/m³Rivière-des-Prairies–Pointe-aux-Trembles, 3 June: 5.8 µg/m³Rivière-des-Prairies–Pointe-aux-Trembles, 4 June: 15.4 µg/m³Rivière-des-Prairies–Pointe-aux-Trembles, 5 June: 16.4 µg/m³Rivière-des-Prairies–Pointe-aux-Trembles, 6 June: 60.6 µg/m³, 11× its usual 5.7Rivière-des-Prairies–Pointe-aux-Trembles, 7 June: 43.5 µg/m³, 7.8× its usual 5.6Rivière-des-Prairies–Pointe-aux-Trembles, 8 June: 19.9 µg/m³Rivière-des-Prairies–Pointe-aux-Trembles, 9 June: 23.4 µg/m³Rivière-des-Prairies–Pointe-aux-Trembles, 10 June: 7.6 µg/m³Rivière-des-Prairies–Pointe-aux-Trembles, 11 June: 13.9 µg/m³Rivière-des-Prairies–Pointe-aux-Trembles, 12 June: 13.7 µg/m³KingstonKingston, 31 May: 4.0 µg/m³Kingston, 1 June: 1.3 µg/m³Kingston, 2 June: 3.3 µg/m³Kingston, 3 June: 5.0 µg/m³Kingston, 4 June: 13.5 µg/m³Kingston, 5 June: 14.0 µg/m³Kingston, 6 June: 59.5 µg/m³, 11× its usual 5.3Kingston, 7 June: 45.4 µg/m³, 8.4× its usual 5.4Kingston, 8 June: 30.3 µg/m³, 5.7× its usual 5.3Kingston, 9 June: 9.4 µg/m³Kingston, 10 June: 6.0 µg/m³Kingston, 11 June: 14.9 µg/m³Kingston, 12 June: 18.9 µg/m³HamiltonHamilton, 31 May: 5.6 µg/m³Hamilton, 1 June: 2.8 µg/m³Hamilton, 2 June: 3.9 µg/m³Hamilton, 3 June: 8.6 µg/m³Hamilton, 4 June: 19.4 µg/m³Hamilton, 5 June: 17.1 µg/m³Hamilton, 6 June: 59.1 µg/m³, 7.2× its usual 8.2Hamilton, 7 June: 32.9 µg/m³, 4.0× its usual 8.2Hamilton, 8 June: 40.8 µg/m³, 5.1× its usual 8.0Hamilton, 9 June: 21.7 µg/m³Hamilton, 10 June: 8.3 µg/m³Hamilton, 11 June: 19.1 µg/m³Hamilton, 12 June: 20.4 µg/m³Sorel-TracySorel-Tracy, 31 May: 5.7 µg/m³Sorel-Tracy, 1 June: 13.2 µg/m³Sorel-Tracy, 2 June: 5.4 µg/m³Sorel-Tracy, 3 June: 5.9 µg/m³Sorel-Tracy, 4 June: 14.7 µg/m³Sorel-Tracy, 5 June: 23.8 µg/m³Sorel-Tracy, 6 June: 58.9 µg/m³, 8.4× its usual 7.0Sorel-Tracy, 7 June: 40.3 µg/m³, 5.8× its usual 7.0Sorel-Tracy, 8 June: 13.0 µg/m³Sorel-Tracy, 9 June: 17.8 µg/m³Sorel-Tracy, 10 June: 8.2 µg/m³Sorel-Tracy, 11 June: 14.5 µg/m³Sorel-Tracy, 12 June: 15.3 µg/m³ShawiniganShawinigan, 31 May: 5.8 µg/m³Shawinigan, 1 June: 1.0 µg/m³Shawinigan, 2 June: 3.1 µg/m³Shawinigan, 3 June: 5.7 µg/m³Shawinigan, 4 June: 13.9 µg/m³Shawinigan, 5 June: 19.2 µg/m³Shawinigan, 6 June: 57.1 µg/m³, 9.5× its usual 6.0Shawinigan, 7 June: 37.5 µg/m³, 6.3× its usual 6.0Shawinigan, 8 June: 8.7 µg/m³Shawinigan, 9 June: 16.8 µg/m³Shawinigan, 10 June: 9.4 µg/m³Shawinigan, 11 June: 11.6 µg/m³Shawinigan, 12 June: 8.8 µg/m³MississaugaMississauga, 31 May: 5.0 µg/m³Mississauga, 1 June: 2.2 µg/m³Mississauga, 2 June: 3.5 µg/m³Mississauga, 3 June: 8.6 µg/m³Mississauga, 4 June: 16.5 µg/m³Mississauga, 5 June: 20.0 µg/m³Mississauga, 6 June: 56.4 µg/m³, 10× its usual 5.5Mississauga, 7 June: 27.2 µg/m³, 4.9× its usual 5.5Mississauga, 8 June: 33.9 µg/m³, 6.2× its usual 5.5Mississauga, 9 June: 21.3 µg/m³Mississauga, 10 June: 8.5 µg/m³Mississauga, 11 June: 18.6 µg/m³Mississauga, 12 June: 15.8 µg/m³Trois-RivièresTrois-Rivières, 31 May: 5.7 µg/m³Trois-Rivières, 1 June: 1.5 µg/m³Trois-Rivières, 2 June: 3.5 µg/m³Trois-Rivières, 3 June: 6.5 µg/m³Trois-Rivières, 4 June: 13.3 µg/m³Trois-Rivières, 5 June: 18.5 µg/m³Trois-Rivières, 6 June: 55.2 µg/m³, 9.0× its usual 6.1Trois-Rivières, 7 June: 40.9 µg/m³, 6.7× its usual 6.1Trois-Rivières, 8 June: 13.7 µg/m³Trois-Rivières, 9 June: 19.0 µg/m³Trois-Rivières, 10 June: 7.7 µg/m³Trois-Rivières, 11 June: 13.7 µg/m³Trois-Rivières, 12 June: 11.6 µg/m³BrossardBrossard, 31 May: 6.1 µg/m³Brossard, 1 June: 1.5 µg/m³Brossard, 2 June: 2.9 µg/m³Brossard, 3 June: 5.0 µg/m³Brossard, 4 June: 14.3 µg/m³Brossard, 5 June: 17.1 µg/m³Brossard, 6 June: 55.1 µg/m³, 9.0× its usual 6.1Brossard, 7 June: 36.4 µg/m³, 6.0× its usual 6.1Brossard, 8 June: 24.3 µg/m³Brossard, 9 June: 24.2 µg/m³Brossard, 10 June: 6.6 µg/m³Brossard, 11 June: 13.7 µg/m³Brossard, 12 June: 15.2 µg/m³31 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
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 June5.515×
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 June6.413×
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 June5.512×
QuébecQuebec, Canada2 60.66 June5.411×
KingstonOntario, Canada3 59.56 June5.311×
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×
OakvilleOntario, Canada3 63.86 June6.111×
MississaugaOntario, Canada3 56.46 June5.510×
Sault Ste. MarieOntario, Canada4 54.57 June5.410×
GuelphOntario, Canada3 54.96 June5.510×
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×
SarniaOntario, Canada5 57.65 June6.49.0×
Trois-RivièresQuebec, Canada2 55.26 June6.19.0×
BrossardQuebec, Canada2 55.16 June6.19.0×
MadisonWisconsin, United States3 49.74 June5.59.0×
Rouyn-NorandaQuebec, Canada3 49.45 June5.59.0×
RochesterMinnesota, United States3 61.93 June7.08.8×
Michigan CityIndiana, United States4 53.45 June6.18.8×
ElginIllinois, United States3 47.45 June5.48.8×
Cedar RapidsIowa, United States5 43.84 June4.98.8×
NewmarketOntario, Canada4 53.76 June6.28.7×
KitchenerOntario, Canada3 63.96 June7.48.6×
Port HuronMichigan, United States5 53.95 June6.38.6×
WaterdownOntario, Canada3 49.76 June5.88.6×
YpsilantiMichigan, United States4 56.06 June6.68.5×
AuroraIllinois, United States3 45.35 June5.38.5×
Saint-Jean-sur-RichelieuQuebec, Canada2 42.56 June4.88.5×
Sorel-TracyQuebec, Canada2 58.96 June7.08.4×
BrantfordOntario, Canada3 67.56 June8.18.3×
WindsorOntario, Canada4 61.36 June7.58.2×
DoltonIllinois, United States4 60.15 June7.67.9×
TaylorMichigan, United States3 53.66 June6.87.9×
ZionIllinois, United States3 44.24 June5.67.9×
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×
Lincoln ParkMichigan, United States3 56.86 June7.57.6×
RochesterNew York, United States2 45.87 June6.07.6×
ChathamOntario, Canada3 45.56 June6.07.6×
East ChicagoIndiana, United States3 54.45 June7.37.5×
AllistonOntario, Canada4 37.36 June4.47.5×
MarquetteMichigan, United States1 36.94 June3.77.4×
Franklin ParkIllinois, United States4 59.55 June8.17.3×
Greater SudburyOntario, Canada3 43.57 June6.07.3×
HamiltonOntario, Canada3 59.16 June8.27.2×
SyracuseNew York, United States2 37.58 June5.27.2×
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×
NorthbrookIllinois, United States3 46.65 June6.96.8×
BloomingtonIllinois, United States3 42.45 June6.26.8×
North BayOntario, Canada2 36.27 June5.36.8×
SherbrookeQuebec, Canada1 34.07 June4.56.8×
Oak LawnIllinois, United States3 48.95 June7.36.7×
DrummondvilleQuebec, Canada2 38.96 June5.86.7×
DearbornMichigan, United States4 56.06 June8.56.6×
CaryIllinois, United States3 45.25 June6.96.6×
DetroitMichigan, United States3 55.06 June8.46.5×
LansingMichigan, United States3 43.95 June6.86.5×
NapervilleIllinois, United States3 50.35 June7.86.4×
JolietIllinois, United States3 47.95 June7.56.4×
South MilwaukeeWisconsin, United States3 40.55 June6.36.4×
OregonOhio, United States5 49.26 June7.86.3×
Iowa CityIowa, United States5 40.54 June6.46.3×
LynnMassachusetts, United States1 33.98 June5.46.3×
HaverhillMassachusetts, United States1 31.48 June5.06.3×
AltoonaPennsylvania, United States2 34.68 June5.66.2×
QuincyMassachusetts, United States1 31.78 June5.16.2×
MilwaukeeWisconsin, United States4 45.65 June7.56.1×
PerrysburgOhio, United States4 45.56 June7.46.1×
PortageIndiana, United States3 44.05 June7.26.1×
PeoriaIllinois, United States3 43.05 June7.06.1×
YoungstownOhio, United States1 42.97 June7.06.1×
JenisonMichigan, United States3 40.45 June6.66.1×
WaukeshaWisconsin, United States4 38.64 June6.36.1×
HermitagePennsylvania, United States1 37.67 June6.26.1×
KalamazooMichigan, United States4 47.46 June7.96.0×
Grand RapidsMichigan, United States3 45.45 June7.66.0×
St. CatharinesOntario, Canada3 39.06 June6.56.0×
LowellMassachusetts, United States1 33.58 June5.66.0×
UticaNew York, United States1 29.68 June4.55.9×
BostonMassachusetts, United States2 34.18 June5.95.8×
MolineIllinois, United States3 32.16 June5.55.8×
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×
ChampaignIllinois, United States2 31.36 June5.55.7×
FraminghamMassachusetts, United States2 28.38 June4.45.7×
WarrenOhio, United States1 46.77 June8.45.6×
GaryIndiana, United States3 46.05 June8.25.6×
PortsmouthOhio, United States2 40.64 June7.35.6×
DerryNew Hampshire, United States1 28.18 June4.85.6×
Shaker HeightsOhio, United States1 33.57 June6.25.4×
PainesvilleOhio, United States2 33.07 June6.15.4×
RedfordMichigan, United States3 51.06 June9.75.3×
South BendIndiana, United States3 37.47 June7.15.3×
AlbanyNew York, United States2 33.18 June6.35.3×
DavenportIowa, United States3 32.36 June6.15.3×
WeirtonWest Virginia, United States2 32.27 June6.15.3×
WorcesterMassachusetts, United States2 28.88 June5.45.3×
North ChicopeeMassachusetts, United States1 26.48 June4.85.3×
BrookfieldIllinois, United States1 34.05 June6.65.2×
PortlandMaine, United States2 29.88 June5.75.2×
GreenfieldMassachusetts, United States2 27.08 June5.25.2×
KeeneNew Hampshire, United States1 26.68 June5.15.2×
BarrieOntario, Canada4 38.06 June7.55.1×
AkronOhio, United States1 37.47 June7.45.1×
HollandMichigan, United States3 37.05 June7.35.1×
SpringfieldIllinois, United States2 36.46 June7.25.1×
Fort WayneIndiana, United States2 33.77 June6.65.1×
EriePennsylvania, United States2 32.87 June6.45.1×
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×
CantonOhio, United States1 43.47 June8.75.0×
State CollegePennsylvania, United States2 30.18 June6.05.0×
Bay CityMichigan, United States3 34.25 June7.04.9×
TopekaKansas, United States1 33.04 June6.84.9×
RockfordIllinois, United States4 32.65 June6.74.9×
MedinaOhio, United States1 31.87 June6.54.9×
MuncieIndiana, United States2 29.17 June6.04.9×
Cleveland HeightsOhio, United States1 28.27 June5.84.9×
OlatheKansas, United States1 32.14 June6.74.8×
HuntingtonWest Virginia, United States1 31.34 June6.54.8×
AugustaMaine, United States1 25.88 June5.44.8×
LafayetteIndiana, United States1 32.27 June6.94.7×
ClintonIowa, United States3 29.66 June6.34.7×
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×
DecaturIllinois, United States2 31.66 June7.24.4×
FlintMichigan, United States3 30.78 June7.04.4×
Weirton HeightsWest Virginia, United States2 28.18 June6.44.4×
WaterlooIowa, United States2 32.84 June7.64.3×
DerbyKansas, United States1 30.04 June7.04.3×
DublinOhio, United States3 29.77 June6.94.3×
Kansas CityKansas, United States1 30.14 June7.34.1×
WilkinsburgPennsylvania, United States1 28.95 June7.04.1×
MuscatineIowa, United States1 26.06 June6.44.1×
ColumbiaMissouri, United States1 25.98 June6.34.1×
SpringfieldMassachusetts, United States1 25.58 June6.24.1×
SteubenvilleOhio, United States4 33.57 June8.34.0×
AshlandKentucky, United States1 29.94 June7.44.0×
KokomoIndiana, United States1 27.97 June7.04.0×
AndersonIndiana, United States1 25.37 June6.34.0×
PittsburghPennsylvania, United States3 30.18 June7.83.9×
Des MoinesIowa, United States3 28.27 June7.23.9×
WyomingMichigan, United States3 38.25 June10.13.8×
WichitaKansas, United States1 29.24 June7.63.8×
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×
WheelingWest Virginia, United States2 28.84 June8.33.5×
AnkenyIowa, United States2 26.37 June8.03.3×
DaytonOhio, United States1 26.24 June7.93.3×
SpringfieldOhio, United States2 26.07 June8.03.3×
ElkhartIndiana, United States1 25.26 June7.63.3×
Granite CityIllinois, United States1 28.37 June8.83.2×
CincinnatiOhio, United States1 25.34 June8.03.2×
LouisvilleKentucky, United States1 25.04 June7.73.2×
West MifflinPennsylvania, United States3 29.45 June9.63.1×
NorwoodOhio, United States1 26.44 June8.53.1×
MiddletownOhio, United States1 28.14 June9.43.0×
St. LouisMissouri, United States1 26.27 June9.92.6×

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 6 of 141 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 141.

Use this page

SmogRank, North-eastern United States and Canada, 3 to 9 June 2025: 196 cities with PM2.5 at twice their usual or more, 3 to 9 June 2025, smogrank.com/episodes/2025-06-03-north-eastern-united-states-and-canada (accessed 4 October 2026).

Download top 10 (PNG)

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

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