SmogRank / Episodes / United States

North-eastern United States and Canada, 24 to 27 July 2025

For 4 days, from 24 to 27 July 2025, 90 cities in the United States and Canada had PM2.5 at least twice their usual for the time of year. The worst reading was Sorel-Tracy, Quebec, Canada: 88.4 µg/m³ on 26 July, about 8.8× its usual 10.1.

No cause namedWe have no fire or smoke records for these days, so we only say what the measurements show.
Cities reached90in 2 countries
Days424 to 27 July 2025
Worst day26 July60 cities counted
Furthest above usual10×Dorval

Day by day

26 July 60 cities at twice their usual or more
Bay CityPort HuronSarniaSouthfieldEastpointeRedfordDearbornDetroitWindsorLincoln ParkTaylorAnn ArborYpsilantiLansingChathamToledoLondonSt. ThomasGrand RapidsWyomingJenisonKalamazooKitchenerClevelandCleveland HeightsHollandPainesvilleShaker HeightsGuelphMedinaBrantfordLimaFort WayneAkronElkhartMiltonAllistonWaterdownHamiltonBramptonSouth BendWarrenCantonOakvilleMississaugaErieWestervilleDublinYoungstownGahannaHermitageColumbusTorontoSpringfieldSt. CatharinesMichigan CityDaytonMuncieKokomoWeirtonSteubenvilleAndersonWeirton HeightsPortageMiddletownLebanonBuffaloGarySouth MilwaukeeMasonMilwaukeeEast ChicagoZionHammondFishersCalumet CityChicagoPittsburghNorthbrookDoltonWhite OakNorwoodWilkinsburgElmwood ParkCincinnatiDes PlainesOak LawnFranklin ParkFort ThomasWest MifflinBridgeviewLafayetteBrookfieldMcKeesportWaukeshaIndianapolisPeterboroughPortsmouthCaryOconomowocNapervilleElginJolietColumbusAuroraJohnstownBloomingtonRochesterBellevilleRockfordTerre HauteMadisonChampaignState CollegeBloomingtonKingstonDecaturPeoriaHagerstownClintonCarlisleSyracuseHarrisburgSpringfieldMolineAshburnDavenportYorkOttawaRockvilleSpringfieldScaggsvilleHunt ValleyLancasterWashingtonRose HillScrantonSouth LaurelMuscatineUticaBaltimoreOxon Hill-GlassmanorReadingEssexEdgewoodUpper AltonIowa CityAllentownCedar RapidsGranite CityEast Saint LouisBethlehemElktonSt. LouisNewarkUniversity CityBearWilmingtonChesterAbingtonWaterlooCamdenRochesterDoverSuperiorSouth VinelandToms RiverColumbiaAnkenyDes MoinesMankatoFort DodgeCoventryLibertyProvidencePawtucketKansas CityRaymoreSaint JosephKansas CityLeawoodOlatheBellevueOmahaLa VistaTopekaSioux FallsLincolnWatertownBangorAberdeenGrand IslandEdmundstonNepeanPhiladelphiaNewmarketElizabethTrentonJersey CityBensalemEwingShakopeeLebanonLindenRouyn-NorandaAppletonBarrieSaguenayNew BrunswickPennsaukenRandolphPatersonBridgeportNorristownFort LeeNew LondonNew York CityPortsmouthNorth BayApple ValleyAtlantic CityGreen BayLexingtonBostonPleasantvilleGreater SudburyWest FargoBurnsvilleFraminghamLowellSewellLynnDerryBrocktonNew HavenBrookingsWorcesterHolbrookCornwallHartfordMilfordHaverhillSaint CloudPortlandSaint MichaelQuincyFall RiverAugustaSaint PaulBayonneSault Ste. MarieWaterburyMinneapolisMarquetteDanburyAlbanyEau ClaireGreenfieldPittsfieldKeeneSpringfieldLewistonBlaineLaconiaNewburghRutlandL'Ancienne-LoretteNorth ChicopeeWhite PlainsNew CityQuébecDuluthBrossardShawiniganSorel-TracyRivière-des-Prairies–Pointe-aux-TremblesSaint-Jean-sur-RichelieuGranbyTrois-RivièresDrummondvilleMontréalSherbrookeDorval
21 Jul222324252627282930
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, 21 July: 19.3 µg/m³Duluth, 22 July: 14.5 µg/m³Duluth, 23 July: 5.9 µg/m³Duluth, 24 July: 54.4 µg/m³, 5.6× its usual 9.8Duluth, 25 July: 59.7 µg/m³, 6.3× its usual 9.5Duluth, 26 July: 27.3 µg/m³Duluth, 27 July: 6.0 µg/m³Duluth, 28 July: 8.0 µg/m³Duluth, 29 July: 32.6 µg/m³Duluth, 30 July: 91.1 µg/m³Saint CloudSaint Cloud, 21 July: 16.9 µg/m³Saint Cloud, 22 July: 9.6 µg/m³Saint Cloud, 23 July: 4.0 µg/m³Saint Cloud, 24 July: 31.2 µg/m³, 3.5× its usual 8.8Saint Cloud, 25 July: 38.4 µg/m³, 4.4× its usual 8.8Saint Cloud, 26 July: 6.2 µg/m³Saint Cloud, 27 July: 4.9 µg/m³Saint Cloud, 28 July: 6.1 µg/m³Saint Cloud, 29 July: 9.8 µg/m³Saint Cloud, 30 July: 53.4 µg/m³West FargoWest Fargo, 21 July: 12.4 µg/m³West Fargo, 22 July: 4.7 µg/m³West Fargo, 23 July: 28.4 µg/m³West Fargo, 24 July: 37.8 µg/m³, 3.9× its usual 9.7West Fargo, 25 July: 11.6 µg/m³West Fargo, 26 July: no readingWest Fargo, 27 July: no readingWest Fargo, 28 July: no readingWest Fargo, 29 July: no readingWest Fargo, 30 July: 58.3 µg/m³Sorel-TracySorel-Tracy, 21 July: 2.8 µg/m³Sorel-Tracy, 22 July: 4.8 µg/m³Sorel-Tracy, 23 July: 6.0 µg/m³Sorel-Tracy, 24 July: 11.3 µg/m³Sorel-Tracy, 25 July: 46.0 µg/m³, 4.6× its usual 10.1Sorel-Tracy, 26 July: 88.4 µg/m³, 8.8× its usual 10.1Sorel-Tracy, 27 July: 33.5 µg/m³, 3.3× its usual 10.1Sorel-Tracy, 28 July: 25.1 µg/m³Sorel-Tracy, 29 July: 16.9 µg/m³Sorel-Tracy, 30 July: 31.5 µg/m³MontréalMontréal, 21 July: 3.6 µg/m³Montréal, 22 July: 3.7 µg/m³Montréal, 23 July: 5.2 µg/m³Montréal, 24 July: 10.4 µg/m³Montréal, 25 July: 30.1 µg/m³, 3.6× its usual 8.4Montréal, 26 July: 82.4 µg/m³, 9.8× its usual 8.4Montréal, 27 July: 31.7 µg/m³, 3.8× its usual 8.4Montréal, 28 July: 19.8 µg/m³Montréal, 29 July: 11.8 µg/m³Montréal, 30 July: 30.7 µg/m³GranbyGranby, 21 July: 4.4 µg/m³Granby, 22 July: 3.9 µg/m³Granby, 23 July: 4.4 µg/m³Granby, 24 July: 10.8 µg/m³Granby, 25 July: 37.1 µg/m³, 4.2× its usual 8.8Granby, 26 July: 81.2 µg/m³, 9.3× its usual 8.7Granby, 27 July: 31.2 µg/m³, 3.6× its usual 8.7Granby, 28 July: 19.6 µg/m³Granby, 29 July: 13.6 µg/m³Granby, 30 July: 24.6 µg/m³DorvalDorval, 21 July: 3.9 µg/m³Dorval, 22 July: 3.4 µg/m³Dorval, 23 July: 4.5 µg/m³Dorval, 24 July: 10.8 µg/m³Dorval, 25 July: 28.9 µg/m³, 3.6× its usual 8.0Dorval, 26 July: 79.8 µg/m³, 10.0× its usual 8.0Dorval, 27 July: 33.2 µg/m³, 4.2× its usual 7.9Dorval, 28 July: 19.6 µg/m³Dorval, 29 July: 12.7 µg/m³Dorval, 30 July: 32.6 µg/m³Trois-RivièresTrois-Rivières, 21 July: 3.1 µg/m³Trois-Rivières, 22 July: 3.2 µg/m³Trois-Rivières, 23 July: 4.6 µg/m³Trois-Rivières, 24 July: 9.7 µg/m³Trois-Rivières, 25 July: 48.4 µg/m³, 5.8× its usual 8.3Trois-Rivières, 26 July: 77.9 µg/m³, 9.4× its usual 8.3Trois-Rivières, 27 July: 35.3 µg/m³, 4.3× its usual 8.3Trois-Rivières, 28 July: 22.6 µg/m³Trois-Rivières, 29 July: 12.7 µg/m³Trois-Rivières, 30 July: 24.3 µg/m³DrummondvilleDrummondville, 21 July: 3.7 µg/m³Drummondville, 22 July: 3.9 µg/m³Drummondville, 23 July: 4.1 µg/m³Drummondville, 24 July: 8.5 µg/m³Drummondville, 25 July: 41.4 µg/m³, 5.2× its usual 8.0Drummondville, 26 July: 77.5 µg/m³, 9.8× its usual 7.9Drummondville, 27 July: 28.4 µg/m³, 3.7× its usual 7.7Drummondville, 28 July: 18.2 µg/m³Drummondville, 29 July: 14.6 µg/m³Drummondville, 30 July: 19.4 µg/m³SherbrookeSherbrooke, 21 July: 4.4 µg/m³Sherbrooke, 22 July: 2.8 µg/m³Sherbrooke, 23 July: 3.6 µg/m³Sherbrooke, 24 July: 8.4 µg/m³Sherbrooke, 25 July: 35.9 µg/m³, 4.5× its usual 7.9Sherbrooke, 26 July: 76.8 µg/m³, 10.0× its usual 7.7Sherbrooke, 27 July: 32.0 µg/m³, 4.2× its usual 7.6Sherbrooke, 28 July: 16.1 µg/m³Sherbrooke, 29 July: 12.2 µg/m³Sherbrooke, 30 July: 17.2 µg/m³Rivière-des-Prairie…Rivière-des-Prairies–Pointe-aux-Trembles, 21 July: 3.2 µg/m³Rivière-des-Prairies–Pointe-aux-Trembles, 22 July: 3.2 µg/m³Rivière-des-Prairies–Pointe-aux-Trembles, 23 July: 5.3 µg/m³Rivière-des-Prairies–Pointe-aux-Trembles, 24 July: 10.0 µg/m³Rivière-des-Prairies–Pointe-aux-Trembles, 25 July: 28.0 µg/m³, 3.5× its usual 7.9Rivière-des-Prairies–Pointe-aux-Trembles, 26 July: 72.9 µg/m³, 9.2× its usual 7.9Rivière-des-Prairies–Pointe-aux-Trembles, 27 July: 29.8 µg/m³, 3.8× its usual 7.9Rivière-des-Prairies–Pointe-aux-Trembles, 28 July: 19.0 µg/m³Rivière-des-Prairies–Pointe-aux-Trembles, 29 July: 11.2 µg/m³Rivière-des-Prairies–Pointe-aux-Trembles, 30 July: 29.2 µg/m³ShawiniganShawinigan, 21 July: 2.5 µg/m³Shawinigan, 22 July: 3.3 µg/m³Shawinigan, 23 July: 5.5 µg/m³Shawinigan, 24 July: 9.0 µg/m³Shawinigan, 25 July: 48.2 µg/m³, 5.1× its usual 9.4Shawinigan, 26 July: 72.3 µg/m³, 7.9× its usual 9.1Shawinigan, 27 July: 37.8 µg/m³, 4.3× its usual 8.8Shawinigan, 28 July: 24.5 µg/m³Shawinigan, 29 July: 17.6 µg/m³Shawinigan, 30 July: 30.5 µg/m³BrossardBrossard, 21 July: 3.8 µg/m³Brossard, 22 July: 5.0 µg/m³Brossard, 23 July: 7.4 µg/m³Brossard, 24 July: 11.5 µg/m³Brossard, 25 July: 26.9 µg/m³, 2.9× its usual 9.2Brossard, 26 July: 70.6 µg/m³, 7.8× its usual 9.1Brossard, 27 July: 30.1 µg/m³, 3.5× its usual 8.7Brossard, 28 July: 19.8 µg/m³Brossard, 29 July: 11.9 µg/m³Brossard, 30 July: 27.3 µg/m³L'Ancienne-LoretteL'Ancienne-Lorette, 21 July: 1.8 µg/m³L'Ancienne-Lorette, 22 July: 4.4 µg/m³L'Ancienne-Lorette, 23 July: 6.0 µg/m³L'Ancienne-Lorette, 24 July: 10.4 µg/m³L'Ancienne-Lorette, 25 July: 37.0 µg/m³, 3.6× its usual 10.3L'Ancienne-Lorette, 26 July: 58.1 µg/m³, 5.8× its usual 10.1L'Ancienne-Lorette, 27 July: 45.0 µg/m³, 4.5× its usual 10.1L'Ancienne-Lorette, 28 July: 27.4 µg/m³L'Ancienne-Lorette, 29 July: no readingL'Ancienne-Lorette, 30 July: 38.8 µg/m³QuébecQuébec, 21 July: 2.0 µg/m³Québec, 22 July: 4.7 µg/m³Québec, 23 July: 5.8 µg/m³Québec, 24 July: 10.1 µg/m³Québec, 25 July: 33.3 µg/m³, 3.7× its usual 8.9Québec, 26 July: 54.7 µg/m³, 6.1× its usual 8.9Québec, 27 July: 41.6 µg/m³, 4.7× its usual 8.9Québec, 28 July: 25.4 µg/m³Québec, 29 July: 18.4 µg/m³Québec, 30 July: 35.4 µg/m³MinneapolisMinneapolis, 21 July: 25.6 µg/m³Minneapolis, 22 July: 13.1 µg/m³Minneapolis, 23 July: 7.4 µg/m³Minneapolis, 24 July: 15.8 µg/m³Minneapolis, 25 July: 49.3 µg/m³, 4.8× its usual 10.2Minneapolis, 26 July: 8.8 µg/m³Minneapolis, 27 July: 5.6 µg/m³Minneapolis, 28 July: 7.2 µg/m³Minneapolis, 29 July: 9.5 µg/m³Minneapolis, 30 July: 54.0 µg/m³Saint PaulSaint Paul, 21 July: 26.2 µg/m³Saint Paul, 22 July: 11.2 µg/m³Saint Paul, 23 July: 6.6 µg/m³Saint Paul, 24 July: 13.8 µg/m³Saint Paul, 25 July: 47.7 µg/m³, 4.7× its usual 10.1Saint Paul, 26 July: 10.1 µg/m³Saint Paul, 27 July: 5.2 µg/m³Saint Paul, 28 July: 6.1 µg/m³Saint Paul, 29 July: 9.2 µg/m³Saint Paul, 30 July: 53.3 µg/m³BlaineBlaine, 21 July: 25.5 µg/m³Blaine, 22 July: 10.4 µg/m³Blaine, 23 July: 6.1 µg/m³Blaine, 24 July: 16.6 µg/m³Blaine, 25 July: 47.3 µg/m³, 5.6× its usual 8.5Blaine, 26 July: 9.0 µg/m³Blaine, 27 July: 5.2 µg/m³Blaine, 28 July: 6.4 µg/m³Blaine, 29 July: 8.4 µg/m³Blaine, 30 July: 49.7 µg/m³Eau ClaireEau Claire, 21 July: 33.4 µg/m³Eau Claire, 22 July: 12.3 µg/m³Eau Claire, 23 July: 6.9 µg/m³Eau Claire, 24 July: 5.2 µg/m³Eau Claire, 25 July: 44.4 µg/m³, 5.0× its usual 8.9Eau Claire, 26 July: 9.4 µg/m³Eau Claire, 27 July: 4.8 µg/m³Eau Claire, 28 July: 5.6 µg/m³Eau Claire, 29 July: 11.1 µg/m³Eau Claire, 30 July: 59.2 µg/m³MarquetteMarquette, 21 July: 6.9 µg/m³Marquette, 22 July: 9.7 µg/m³Marquette, 23 July: 13.3 µg/m³Marquette, 24 July: 16.5 µg/m³Marquette, 25 July: 39.0 µg/m³, 4.6× its usual 8.5Marquette, 26 July: 40.7 µg/m³, 4.9× its usual 8.3Marquette, 27 July: 8.6 µg/m³Marquette, 28 July: 11.0 µg/m³Marquette, 29 July: 42.7 µg/m³Marquette, 30 July: 112.0 µg/m³BurnsvilleBurnsville, 21 July: 22.4 µg/m³Burnsville, 22 July: 10.7 µg/m³Burnsville, 23 July: 6.9 µg/m³Burnsville, 24 July: 9.1 µg/m³Burnsville, 25 July: 39.3 µg/m³, 3.9× its usual 10.1Burnsville, 26 July: 8.0 µg/m³Burnsville, 27 July: 5.1 µg/m³Burnsville, 28 July: 6.0 µg/m³Burnsville, 29 July: no readingBurnsville, 30 July: 53.8 µg/m³Saint MichaelSaint Michael, 21 July: 17.2 µg/m³Saint Michael, 22 July: 10.1 µg/m³Saint Michael, 23 July: 4.9 µg/m³Saint Michael, 24 July: 18.8 µg/m³Saint Michael, 25 July: 39.1 µg/m³, 4.4× its usual 8.9Saint Michael, 26 July: 6.7 µg/m³Saint Michael, 27 July: 4.8 µg/m³Saint Michael, 28 July: 6.3 µg/m³Saint Michael, 29 July: 8.2 µg/m³Saint Michael, 30 July: 46.3 µg/m³Sault Ste. MarieSault Ste. Marie, 21 July: 4.0 µg/m³Sault Ste. Marie, 22 July: 3.1 µg/m³Sault Ste. Marie, 23 July: 8.9 µg/m³Sault Ste. Marie, 24 July: 4.8 µg/m³Sault Ste. Marie, 25 July: 34.1 µg/m³, 4.3× its usual 8.0Sault Ste. Marie, 26 July: 38.2 µg/m³, 4.8× its usual 8.0Sault Ste. Marie, 27 July: 12.8 µg/m³Sault Ste. Marie, 28 July: 12.6 µg/m³Sault Ste. Marie, 29 July: 19.5 µg/m³Sault Ste. Marie, 30 July: 71.6 µg/m³Green BayGreen Bay, 21 July: 8.4 µg/m³Green Bay, 22 July: 13.6 µg/m³Green Bay, 23 July: 13.0 µg/m³Green Bay, 24 July: 4.7 µg/m³Green Bay, 25 July: 37.7 µg/m³, 3.8× its usual 9.8Green Bay, 26 July: 26.9 µg/m³, 2.8× its usual 9.5Green Bay, 27 July: 8.2 µg/m³Green Bay, 28 July: 7.7 µg/m³Green Bay, 29 July: 9.5 µg/m³Green Bay, 30 July: 85.9 µg/m³Greater SudburyGreater Sudbury, 21 July: 3.3 µg/m³Greater Sudbury, 22 July: 4.6 µg/m³Greater Sudbury, 23 July: 4.8 µg/m³Greater Sudbury, 24 July: 5.3 µg/m³Greater Sudbury, 25 July: 32.0 µg/m³, 3.8× its usual 8.5Greater Sudbury, 26 July: 33.6 µg/m³, 3.9× its usual 8.6Greater Sudbury, 27 July: 22.4 µg/m³Greater Sudbury, 28 July: 8.3 µg/m³Greater Sudbury, 29 July: 11.1 µg/m³Greater Sudbury, 30 July: 63.1 µg/m³Apple ValleyApple Valley, 21 July: 18.7 µg/m³Apple Valley, 22 July: 9.5 µg/m³Apple Valley, 23 July: 6.7 µg/m³Apple Valley, 24 July: 7.3 µg/m³Apple Valley, 25 July: 32.1 µg/m³, 3.8× its usual 8.4Apple Valley, 26 July: 5.9 µg/m³Apple Valley, 27 July: 4.1 µg/m³Apple Valley, 28 July: 5.4 µg/m³Apple Valley, 29 July: 7.9 µg/m³Apple Valley, 30 July: 46.0 µg/m³Saint-Jean-sur-Rich…Saint-Jean-sur-Richelieu, 21 July: 3.5 µg/m³Saint-Jean-sur-Richelieu, 22 July: 2.9 µg/m³Saint-Jean-sur-Richelieu, 23 July: 3.3 µg/m³Saint-Jean-sur-Richelieu, 24 July: 7.5 µg/m³Saint-Jean-sur-Richelieu, 25 July: 21.7 µg/m³Saint-Jean-sur-Richelieu, 26 July: 63.3 µg/m³, 9.3× its usual 6.8Saint-Jean-sur-Richelieu, 27 July: 25.5 µg/m³, 3.8× its usual 6.7Saint-Jean-sur-Richelieu, 28 July: 15.6 µg/m³Saint-Jean-sur-Richelieu, 29 July: 9.7 µg/m³Saint-Jean-sur-Richelieu, 30 July: 21.5 µg/m³AlbanyAlbany, 21 July: 8.8 µg/m³Albany, 22 July: 3.9 µg/m³Albany, 23 July: 7.6 µg/m³Albany, 24 July: 12.4 µg/m³Albany, 25 July: 13.4 µg/m³Albany, 26 July: 47.8 µg/m³, 4.9× its usual 9.7Albany, 27 July: 44.4 µg/m³, 4.9× its usual 9.1Albany, 28 July: 18.4 µg/m³Albany, 29 July: 16.0 µg/m³Albany, 30 July: 12.7 µg/m³RutlandRutland, 21 July: 4.6 µg/m³Rutland, 22 July: 3.1 µg/m³Rutland, 23 July: 4.3 µg/m³Rutland, 24 July: 10.6 µg/m³Rutland, 25 July: 11.6 µg/m³Rutland, 26 July: 46.0 µg/m³, 5.8× its usual 8.0Rutland, 27 July: 27.6 µg/m³, 3.5× its usual 7.9Rutland, 28 July: 13.8 µg/m³Rutland, 29 July: 11.5 µg/m³Rutland, 30 July: 8.5 µg/m³SpringfieldSpringfield, 21 July: 8.9 µg/m³Springfield, 22 July: 3.9 µg/m³Springfield, 23 July: 5.8 µg/m³Springfield, 24 July: 7.6 µg/m³Springfield, 25 July: 8.6 µg/m³Springfield, 26 July: 42.6 µg/m³, 5.5× its usual 7.7Springfield, 27 July: 35.4 µg/m³, 4.7× its usual 7.5Springfield, 28 July: 20.5 µg/m³Springfield, 29 July: 13.2 µg/m³Springfield, 30 July: 9.6 µg/m³PittsfieldPittsfield, 21 July: 8.5 µg/m³Pittsfield, 22 July: no readingPittsfield, 23 July: 5.8 µg/m³Pittsfield, 24 July: 9.5 µg/m³Pittsfield, 25 July: 9.5 µg/m³Pittsfield, 26 July: 41.9 µg/m³, 5.4× its usual 7.7Pittsfield, 27 July: 35.1 µg/m³, 4.7× its usual 7.5Pittsfield, 28 July: no readingPittsfield, 29 July: 12.0 µg/m³Pittsfield, 30 July: 7.8 µg/m³DanburyDanbury, 21 July: 11.2 µg/m³Danbury, 22 July: 5.1 µg/m³Danbury, 23 July: 5.5 µg/m³Danbury, 24 July: 7.2 µg/m³Danbury, 25 July: 10.4 µg/m³Danbury, 26 July: 41.0 µg/m³, 4.9× its usual 8.3Danbury, 27 July: 32.0 µg/m³, 4.0× its usual 8.1Danbury, 28 July: 13.6 µg/m³Danbury, 29 July: 12.8 µg/m³Danbury, 30 July: 10.0 µg/m³KeeneKeene, 21 July: 5.0 µg/m³Keene, 22 July: 3.0 µg/m³Keene, 23 July: 5.1 µg/m³Keene, 24 July: 9.3 µg/m³Keene, 25 July: 8.3 µg/m³Keene, 26 July: 39.8 µg/m³, 5.5× its usual 7.2Keene, 27 July: 33.9 µg/m³, 4.8× its usual 7.0Keene, 28 July: 16.0 µg/m³Keene, 29 July: 12.0 µg/m³Keene, 30 July: 7.8 µg/m³PortlandPortland, 21 July: 5.6 µg/m³Portland, 22 July: 2.5 µg/m³Portland, 23 July: 5.5 µg/m³Portland, 24 July: 9.0 µg/m³Portland, 25 July: 13.7 µg/m³Portland, 26 July: 39.1 µg/m³, 4.4× its usual 8.9Portland, 27 July: 23.2 µg/m³Portland, 28 July: 13.3 µg/m³Portland, 29 July: 14.2 µg/m³Portland, 30 July: 11.9 µg/m³GreenfieldGreenfield, 21 July: 6.5 µg/m³Greenfield, 22 July: 2.8 µg/m³Greenfield, 23 July: 4.4 µg/m³Greenfield, 24 July: 7.3 µg/m³Greenfield, 25 July: 6.2 µg/m³Greenfield, 26 July: 39.0 µg/m³, 5.4× its usual 7.2Greenfield, 27 July: 34.5 µg/m³, 4.9× its usual 7.1Greenfield, 28 July: 15.5 µg/m³Greenfield, 29 July: 10.6 µg/m³Greenfield, 30 July: 6.9 µg/m³WaterburyWaterbury, 21 July: 10.5 µg/m³Waterbury, 22 July: 3.9 µg/m³Waterbury, 23 July: 5.0 µg/m³Waterbury, 24 July: 6.7 µg/m³Waterbury, 25 July: 9.3 µg/m³Waterbury, 26 July: 38.7 µg/m³, 4.8× its usual 8.1Waterbury, 27 July: 32.7 µg/m³, 4.1× its usual 8.0Waterbury, 28 July: 14.1 µg/m³Waterbury, 29 July: 12.7 µg/m³Waterbury, 30 July: 8.6 µg/m³LewistonLewiston, 21 July: 5.5 µg/m³Lewiston, 22 July: 3.2 µg/m³Lewiston, 23 July: 5.5 µg/m³Lewiston, 24 July: 8.0 µg/m³Lewiston, 25 July: 15.8 µg/m³Lewiston, 26 July: 38.0 µg/m³, 5.6× its usual 6.8Lewiston, 27 July: 19.3 µg/m³Lewiston, 28 July: 12.9 µg/m³Lewiston, 29 July: 10.3 µg/m³Lewiston, 30 July: 12.1 µg/m³North ChicopeeNorth Chicopee, 21 July: 6.4 µg/m³North Chicopee, 22 July: 3.0 µg/m³North Chicopee, 23 July: 4.6 µg/m³North Chicopee, 24 July: 6.4 µg/m³North Chicopee, 25 July: 7.1 µg/m³North Chicopee, 26 July: 37.8 µg/m³, 5.9× its usual 6.4North Chicopee, 27 July: 30.8 µg/m³, 4.9× its usual 6.3North Chicopee, 28 July: 15.0 µg/m³North Chicopee, 29 July: 10.9 µg/m³North Chicopee, 30 July: 7.4 µg/m³HartfordHartford, 21 July: 10.8 µg/m³Hartford, 22 July: 4.2 µg/m³Hartford, 23 July: 6.4 µg/m³Hartford, 24 July: 7.7 µg/m³Hartford, 25 July: 10.0 µg/m³Hartford, 26 July: 37.6 µg/m³, 4.3× its usual 8.7Hartford, 27 July: 34.8 µg/m³, 4.0× its usual 8.6Hartford, 28 July: 18.0 µg/m³Hartford, 29 July: 13.8 µg/m³Hartford, 30 July: 11.3 µg/m³New CityNew City, 21 July: 7.3 µg/m³New City, 22 July: 2.1 µg/m³New City, 23 July: 3.9 µg/m³New City, 24 July: 6.6 µg/m³New City, 25 July: 8.1 µg/m³New City, 26 July: 37.5 µg/m³, 6.0× its usual 6.3New City, 27 July: 25.6 µg/m³, 4.3× its usual 5.9New City, 28 July: 8.1 µg/m³New City, 29 July: 7.6 µg/m³New City, 30 July: 9.4 µg/m³AugustaAugusta, 21 July: 4.5 µg/m³Augusta, 22 July: 2.6 µg/m³Augusta, 23 July: 4.5 µg/m³Augusta, 24 July: 7.3 µg/m³Augusta, 25 July: 14.8 µg/m³Augusta, 26 July: 36.7 µg/m³, 4.6× its usual 7.9Augusta, 27 July: 21.6 µg/m³Augusta, 28 July: 15.5 µg/m³Augusta, 29 July: 9.9 µg/m³Augusta, 30 July: 11.8 µg/m³White PlainsWhite Plains, 21 July: 8.2 µg/m³White Plains, 22 July: 2.5 µg/m³White Plains, 23 July: 3.0 µg/m³White Plains, 24 July: 5.1 µg/m³White Plains, 25 July: 10.4 µg/m³White Plains, 26 July: 36.6 µg/m³, 6.0× its usual 6.1White Plains, 27 July: 29.2 µg/m³, 4.9× its usual 5.9White Plains, 28 July: 7.3 µg/m³White Plains, 29 July: 11.1 µg/m³White Plains, 30 July: 10.7 µg/m³NepeanNepean, 21 July: 4.7 µg/m³Nepean, 22 July: 2.4 µg/m³Nepean, 23 July: 3.9 µg/m³Nepean, 24 July: 15.1 µg/m³Nepean, 25 July: 22.6 µg/m³Nepean, 26 July: 35.8 µg/m³, 2.2× its usual 16.6Nepean, 27 July: 30.5 µg/m³Nepean, 28 July: 31.7 µg/m³Nepean, 29 July: 23.8 µg/m³Nepean, 30 July: 57.6 µg/m³NewburghNewburgh, 21 July: 5.9 µg/m³Newburgh, 22 July: 2.4 µg/m³Newburgh, 23 July: 4.6 µg/m³Newburgh, 24 July: 7.1 µg/m³Newburgh, 25 July: 7.2 µg/m³Newburgh, 26 July: 35.3 µg/m³, 5.8× its usual 6.1Newburgh, 27 July: 24.9 µg/m³Newburgh, 28 July: 8.5 µg/m³Newburgh, 29 July: 12.8 µg/m³Newburgh, 30 July: 9.4 µg/m³SewellSewell, 21 July: 11.7 µg/m³Sewell, 22 July: 17.7 µg/m³Sewell, 23 July: 10.3 µg/m³Sewell, 24 July: 10.3 µg/m³Sewell, 25 July: 18.8 µg/m³Sewell, 26 July: 27.1 µg/m³, 3.0× its usual 9.0Sewell, 27 July: 34.9 µg/m³, 4.0× its usual 8.8Sewell, 28 July: 15.3 µg/m³Sewell, 29 July: 18.9 µg/m³Sewell, 30 July: 18.0 µg/m³CornwallCornwall, 21 July: 5.0 µg/m³Cornwall, 22 July: 3.8 µg/m³Cornwall, 23 July: 4.1 µg/m³Cornwall, 24 July: 11.4 µg/m³Cornwall, 25 July: 12.9 µg/m³Cornwall, 26 July: 34.3 µg/m³, 4.3× its usual 8.0Cornwall, 27 July: 14.3 µg/m³Cornwall, 28 July: 16.8 µg/m³Cornwall, 29 July: 12.9 µg/m³Cornwall, 30 July: 33.4 µg/m³PleasantvillePleasantville, 21 July: 6.5 µg/m³Pleasantville, 22 July: 9.9 µg/m³Pleasantville, 23 July: 4.5 µg/m³Pleasantville, 24 July: 4.1 µg/m³Pleasantville, 25 July: 9.0 µg/m³Pleasantville, 26 July: 33.4 µg/m³, 3.9× its usual 8.5Pleasantville, 27 July: 23.9 µg/m³Pleasantville, 28 July: 8.8 µg/m³Pleasantville, 29 July: 12.7 µg/m³Pleasantville, 30 July: 14.2 µg/m³New HavenNew Haven, 21 July: 11.6 µg/m³New Haven, 22 July: 4.4 µg/m³New Haven, 23 July: 6.4 µg/m³New Haven, 24 July: 6.5 µg/m³New Haven, 25 July: 12.2 µg/m³New Haven, 26 July: 33.2 µg/m³, 4.1× its usual 8.1New Haven, 27 July: 31.0 µg/m³, 3.9× its usual 7.9New Haven, 28 July: 14.2 µg/m³New Haven, 29 July: 17.5 µg/m³New Haven, 30 July: 12.9 µg/m³Atlantic CityAtlantic City, 21 July: 5.7 µg/m³Atlantic City, 22 July: 9.3 µg/m³Atlantic City, 23 July: 4.1 µg/m³Atlantic City, 24 July: 4.1 µg/m³Atlantic City, 25 July: 13.1 µg/m³Atlantic City, 26 July: 33.0 µg/m³, 3.8× its usual 8.6Atlantic City, 27 July: 23.4 µg/m³Atlantic City, 28 July: 8.7 µg/m³Atlantic City, 29 July: 13.4 µg/m³Atlantic City, 30 July: 13.4 µg/m³New York CityNew York City, 21 July: 10.8 µg/m³New York City, 22 July: 5.4 µg/m³New York City, 23 July: 5.2 µg/m³New York City, 24 July: 6.3 µg/m³New York City, 25 July: 12.3 µg/m³New York City, 26 July: 30.4 µg/m³, 3.4× its usual 8.9New York City, 27 July: 32.6 µg/m³, 3.7× its usual 8.8New York City, 28 July: 12.4 µg/m³New York City, 29 July: 17.5 µg/m³New York City, 30 July: 14.1 µg/m³Fall RiverFall River, 21 July: 10.2 µg/m³Fall River, 22 July: 3.0 µg/m³Fall River, 23 July: 3.2 µg/m³Fall River, 24 July: 3.8 µg/m³Fall River, 25 July: 7.5 µg/m³Fall River, 26 July: 32.3 µg/m³, 4.6× its usual 7.0Fall River, 27 July: 19.4 µg/m³Fall River, 28 July: 18.5 µg/m³Fall River, 29 July: 12.2 µg/m³Fall River, 30 July: 10.0 µg/m³BrocktonBrockton, 21 July: 8.3 µg/m³Brockton, 22 July: 3.1 µg/m³Brockton, 23 July: 4.0 µg/m³Brockton, 24 July: 5.2 µg/m³Brockton, 25 July: 8.0 µg/m³Brockton, 26 July: 32.0 µg/m³, 4.1× its usual 7.8Brockton, 27 July: 27.5 µg/m³, 3.6× its usual 7.7Brockton, 28 July: 19.3 µg/m³Brockton, 29 July: 14.8 µg/m³Brockton, 30 July: 11.1 µg/m³BridgeportBridgeport, 21 July: 11.0 µg/m³Bridgeport, 22 July: 4.0 µg/m³Bridgeport, 23 July: 4.2 µg/m³Bridgeport, 24 July: 5.5 µg/m³Bridgeport, 25 July: 10.7 µg/m³Bridgeport, 26 July: 31.7 µg/m³, 3.6× its usual 8.9Bridgeport, 27 July: 30.3 µg/m³, 3.5× its usual 8.6Bridgeport, 28 July: 11.2 µg/m³Bridgeport, 29 July: 13.5 µg/m³Bridgeport, 30 July: 10.0 µg/m³LaconiaLaconia, 21 July: 3.3 µg/m³Laconia, 22 July: 1.2 µg/m³Laconia, 23 July: 1.9 µg/m³Laconia, 24 July: 6.0 µg/m³Laconia, 25 July: 7.3 µg/m³Laconia, 26 July: 30.9 µg/m³, 5.8× its usual 5.3Laconia, 27 July: 21.0 µg/m³Laconia, 28 July: 11.1 µg/m³Laconia, 29 July: 8.9 µg/m³Laconia, 30 July: 5.7 µg/m³QuincyQuincy, 21 July: 7.0 µg/m³Quincy, 22 July: 2.8 µg/m³Quincy, 23 July: 3.7 µg/m³Quincy, 24 July: 5.3 µg/m³Quincy, 25 July: 7.5 µg/m³Quincy, 26 July: 30.7 µg/m³, 4.6× its usual 6.7Quincy, 27 July: 23.8 µg/m³Quincy, 28 July: 16.8 µg/m³Quincy, 29 July: 12.6 µg/m³Quincy, 30 July: 10.2 µg/m³HolbrookHolbrook, 21 July: 11.3 µg/m³Holbrook, 22 July: 4.6 µg/m³Holbrook, 23 July: 3.6 µg/m³Holbrook, 24 July: 3.9 µg/m³Holbrook, 25 July: 8.0 µg/m³Holbrook, 26 July: 30.7 µg/m³, 4.3× its usual 7.2Holbrook, 27 July: 26.3 µg/m³, 3.7× its usual 7.1Holbrook, 28 July: 9.5 µg/m³Holbrook, 29 July: 10.4 µg/m³Holbrook, 30 July: 10.9 µg/m³BarrieBarrie, 21 July: 5.9 µg/m³Barrie, 22 July: 3.8 µg/m³Barrie, 23 July: 6.6 µg/m³Barrie, 24 July: 10.5 µg/m³Barrie, 25 July: 15.5 µg/m³Barrie, 26 July: 30.6 µg/m³, 3.1× its usual 10.0Barrie, 27 July: 10.1 µg/m³Barrie, 28 July: 11.7 µg/m³Barrie, 29 July: 8.5 µg/m³Barrie, 30 July: 29.0 µg/m³PennsaukenPennsauken, 21 July: 8.8 µg/m³Pennsauken, 22 July: 9.1 µg/m³Pennsauken, 23 July: 7.3 µg/m³Pennsauken, 24 July: 10.2 µg/m³Pennsauken, 25 July: 13.8 µg/m³Pennsauken, 26 July: 27.9 µg/m³, 2.9× its usual 9.5Pennsauken, 27 July: 30.4 µg/m³, 3.3× its usual 9.1Pennsauken, 28 July: 11.0 µg/m³Pennsauken, 29 July: 15.7 µg/m³Pennsauken, 30 July: 17.5 µg/m³LexingtonLexington, 21 July: no readingLexington, 22 July: no readingLexington, 23 July: no readingLexington, 24 July: no readingLexington, 25 July: no readingLexington, 26 July: no readingLexington, 27 July: 41.0 µg/m³, 3.8× its usual 10.7Lexington, 28 July: 30.0 µg/m³Lexington, 29 July: 23.2 µg/m³Lexington, 30 July: 14.4 µg/m³PatersonPaterson, 21 July: 7.7 µg/m³Paterson, 22 July: 5.2 µg/m³Paterson, 23 July: 6.3 µg/m³Paterson, 24 July: 7.8 µg/m³Paterson, 25 July: 11.5 µg/m³Paterson, 26 July: 23.1 µg/m³Paterson, 27 July: 30.4 µg/m³, 3.4× its usual 9.0Paterson, 28 July: 10.9 µg/m³Paterson, 29 July: 11.7 µg/m³Paterson, 30 July: 10.7 µg/m³21 Jul222324252627282930
The 60 cities with the highest readings of 90, 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
DorvalQuebec, Canada3 79.826 July8.010×
SherbrookeQuebec, Canada3 76.826 July7.710×
MontréalQuebec, Canada3 82.426 July8.49.8×
DrummondvilleQuebec, Canada3 77.526 July7.99.8×
Trois-RivièresQuebec, Canada3 77.926 July8.39.4×
GranbyQuebec, Canada3 81.226 July8.79.3×
Saint-Jean-sur-RichelieuQuebec, Canada2 63.326 July6.89.3×
Rivière-des-Prairies–Pointe-aux-TremblesQuebec, Canada3 72.926 July7.99.2×
Sorel-TracyQuebec, Canada3 88.426 July10.18.8×
ShawiniganQuebec, Canada3 72.326 July9.17.9×
BrossardQuebec, Canada3 70.626 July9.17.8×
DuluthMinnesota, United States2 59.725 July9.56.3×
QuébecQuebec, Canada3 54.726 July8.96.1×
New CityNew York, United States2 37.526 July6.36.0×
White PlainsNew York, United States2 36.626 July6.16.0×
North ChicopeeMassachusetts, United States2 37.826 July6.45.9×
L'Ancienne-LoretteQuebec, Canada3 58.126 July10.15.8×
RutlandVermont, United States2 46.026 July8.05.8×
NewburghNew York, United States1 35.326 July6.15.8×
LaconiaNew Hampshire, United States1 30.926 July5.35.8×
BlaineMinnesota, United States1 47.325 July8.55.6×
LewistonMaine, United States1 38.026 July6.85.6×
SpringfieldMassachusetts, United States2 42.626 July7.75.5×
KeeneNew Hampshire, United States2 39.826 July7.25.5×
PittsfieldMassachusetts, United States2 41.926 July7.75.4×
GreenfieldMassachusetts, United States2 39.026 July7.25.4×
Eau ClaireWisconsin, United States1 44.425 July8.95.0×
AlbanyNew York, United States2 47.826 July9.74.9×
DanburyConnecticut, United States2 41.026 July8.34.9×
MarquetteMichigan, United States2 40.726 July8.34.9×
MinneapolisMinnesota, United States1 49.325 July10.24.8×
WaterburyConnecticut, United States2 38.726 July8.14.8×
Sault Ste. MarieOntario, Canada2 38.226 July8.04.8×
BayonneNew Jersey, United States1 27.127 July5.74.8×
Saint PaulMinnesota, United States1 47.725 July10.14.7×
AugustaMaine, United States1 36.726 July7.94.6×
Fall RiverMassachusetts, United States1 32.326 July7.04.6×
QuincyMassachusetts, United States1 30.726 July6.74.6×
Saint MichaelMinnesota, United States1 39.125 July8.94.4×
PortlandMaine, United States1 39.126 July8.94.4×
Saint CloudMinnesota, United States2 38.425 July8.84.4×
HaverhillMassachusetts, United States1 28.727 July6.54.4×
MilfordMassachusetts, United States2 27.027 July6.24.4×
HartfordConnecticut, United States2 37.626 July8.74.3×
CornwallOntario, Canada1 34.326 July8.04.3×
HolbrookNew York, United States2 30.726 July7.24.3×
WorcesterMassachusetts, United States2 29.926 July7.04.3×
BrookingsSouth Dakota, United States1 28.824 July6.84.2×
New HavenConnecticut, United States2 33.226 July8.14.1×
BrocktonMassachusetts, United States2 32.026 July7.84.1×
DerryNew Hampshire, United States1 28.927 July7.04.1×
LynnMassachusetts, United States2 28.026 July6.94.1×
SewellNew Jersey, United States2 34.927 July8.84.0×
LowellMassachusetts, United States1 27.527 July6.84.0×
FraminghamMassachusetts, United States1 25.127 July6.24.0×
BurnsvilleMinnesota, United States1 39.325 July10.13.9×
West FargoNorth Dakota, United States1 37.824 July9.73.9×
Greater SudburyOntario, Canada2 33.626 July8.63.9×
PleasantvilleNew Jersey, United States1 33.426 July8.53.9×
BostonMassachusetts, United States2 29.626 July7.63.9×
LexingtonMassachusetts, United States1 41.027 July10.73.8×
Green BayWisconsin, United States2 37.725 July9.83.8×
Atlantic CityNew Jersey, United States1 33.026 July8.63.8×
Apple ValleyMinnesota, United States1 32.125 July8.43.8×
North BayOntario, Canada1 30.326 July8.03.8×
PortsmouthNew Hampshire, United States1 28.326 July7.43.8×
New York CityNew York, United States2 32.627 July8.83.7×
New LondonConnecticut, United States2 30.326 July8.13.7×
Fort LeeNew Jersey, United States2 28.727 July7.83.7×
NorristownPennsylvania, United States1 27.127 July7.43.7×
BridgeportConnecticut, United States2 31.726 July8.93.6×
PatersonNew Jersey, United States1 30.427 July9.03.4×
RandolphNew Jersey, United States1 27.927 July8.13.4×
PennsaukenNew Jersey, United States2 30.427 July9.13.3×
New BrunswickNew Jersey, United States2 27.627 July8.43.3×
SaguenayQuebec, Canada1 27.927 July8.83.2×
BarrieOntario, Canada1 30.626 July10.03.1×
AppletonWisconsin, United States1 27.725 July9.03.1×
Rouyn-NorandaQuebec, Canada1 25.126 July8.13.1×
LindenNew Jersey, United States2 27.827 July9.33.0×
LebanonPennsylvania, United States1 26.327 July8.73.0×
ShakopeeMinnesota, United States1 28.325 July9.92.9×
EwingNew Jersey, United States1 27.727 July9.42.9×
BensalemPennsylvania, United States1 27.527 July9.52.9×
Jersey CityNew Jersey, United States1 26.727 July9.42.8×
TrentonNew Jersey, United States1 26.127 July9.32.8×
ElizabethNew Jersey, United States1 27.427 July10.12.7×
NewmarketOntario, Canada1 25.526 July10.02.6×
PhiladelphiaPennsylvania, United States1 25.927 July10.32.5×
NepeanOntario, Canada1 35.826 July16.62.2×

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 13 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, 24 to 27 July 2025: 90 cities with PM2.5 at twice their usual or more, 24 to 27 July 2025, smogrank.com/episodes/2025-07-24-north-eastern-united-states-and-canada (accessed 4 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.