SmogRank / Episodes / United States

North-eastern United States and Canada, February 2026

For 6 days, from 14 to 19 February 2026, 96 cities in the United States and Canada had PM2.5 at least twice their usual for the time of year. The worst reading was Lancaster, Pennsylvania, United States: 54.3 µg/m³ on 15 February, about 6.4× its usual 8.5.

No cause namedWe have no fire or smoke records for these days, so we only say what the measurements show.
Cities reached96in 2 countries
Days614 to 19 February 2026
Worst day15 February54 cities counted
Furthest above usual11×Nepean

Day by day

15 February 54 cities at twice their usual or more
PainesvilleCleveland HeightsShaker HeightsClevelandBrantfordWarrenAkronMedinaHermitageYoungstownRoyal OakCantonSt. CatharinesWeirtonWeirton HeightsSteubenvillePerrysburgBuffaloPittsburghUpper Saint ClairWilkinsburgWest MifflinMcKeesportWestervilleGahannaDublinColumbusLimaJohnstownPeterboroughSpringfieldAltoonaRochesterDaytonFort WayneLebanonMiddletownMasonJenisonMuncieHagerstownSouth BendAndersonIndianapolisMichigan CityHunt ValleyBaltimoreScrantonEssexEdgewoodEast ChicagoHammondCalumet CityUticaBlue IslandElktonNewarkOak LawnNilesZionNorthbrookBridgeviewPark RidgeBearJolietNapervilleCaryGreen BaySewellBensalemEwingRandolphTrentonSouth VinelandAppletonChampaignNew BrunswickNewburghBayonneNew CityPleasantvilleToms RiverAtlantic CityWhite PlainsBloomingtonMadisonDecaturMiddletonDorvalPittsfieldMontréalBridgeportPeoriaRivière-des-Prairies–Pointe-aux-TremblesBrossardRutlandHolbrookSaint-Jean-sur-RichelieuNew HavenSpringfieldGreenfieldNorth ChicopeeGranbyKeeneNew LondonDrummondvilleWorcesterMuscatineCoventryMilfordSherbrookeLaconiaFraminghamProvidenceDerryLowellEau ClaireFall RiverHaverhillBostonBrocktonQuincyLynnPortsmouthWaterlooRochesterPortlandLewistonAugustaSaint PaulApple ValleyBurnsvilleMinneapolisBlaineSkokieAbingtonCamdenEvergreen ParkToledoWyomingRedfordSouth MilwaukeeBay CityDoltonChicagoPhiladelphiaOregonKalamazooBrookfieldLincoln ParkElkhartWheatonHollandPawtucketYpsilantiWindsorFranklin ParkState CollegeHamiltonDearbornPennsaukenWaukeshaClintonElizabethNorristownTaylorLansingEvanstonMilwaukeeCedar RapidsLindenErieRockfordIowa CityKitchenerGrand RapidsDes PlainesChesterWilmingtonWaterdownGuelphElmwood ParkFort LeeOttawaHarrisburgCarlisleSt. ThomasSpringfieldChathamPort HuronDetroitWaterburyNew York CityAuroraElginJersey CityBramptonLondonOakvilleMiltonEastpointeYorkDavenportBellevilleBarrieHartfordAnn ArborBethlehemMolineMississaugaKingstonOconomowocLebanonAllentownCornwallSyracuseDanburyTorontoAllistonAlbanySarniaNewmarketReadingPatersonLancasterLexingtonSouthfieldNewtonGatineauNepean
11 Feb1213141516171819202122
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

Port HuronPort Huron, 11 February: 3.1 µg/m³, 0.4× usualPort Huron, 12 February: 5.2 µg/m³, 0.7× usualPort Huron, 13 February: 25.5 µg/m³, 3.4× usualPort Huron, 14 February: 23.1 µg/m³, 3.1× usualPort Huron, 15 February: 34.9 µg/m³, 4.7× usualPort Huron, 16 February: 28.2 µg/m³, 3.8× usualPort Huron, 17 February: 24.2 µg/m³, 3.3× usualPort Huron, 18 February: 17.7 µg/m³, 2.4× usualPort Huron, 19 February: 10.2 µg/m³, 1.4× usualPort Huron, 20 February: 7.2 µg/m³, 1.0× usualPort Huron, 21 February: 3.6 µg/m³, 0.5× usualPort Huron, 22 February: 2.8 µg/m³, 0.4× usualLancasterLancaster, 11 February: 15.8 µg/m³, 1.9× usualLancaster, 12 February: 4.2 µg/m³, 0.5× usualLancaster, 13 February: 8.5 µg/m³, 1.0× usualLancaster, 14 February: 31.0 µg/m³, 3.6× usualLancaster, 15 February: 54.3 µg/m³, 6.4× usualLancaster, 16 February: 15.7 µg/m³, 1.8× usualLancaster, 17 February: 27.7 µg/m³, 3.3× usualLancaster, 18 February: 29.6 µg/m³, 3.5× usualLancaster, 19 February: 27.4 µg/m³, 3.2× usualLancaster, 20 February: 8.7 µg/m³, 1.0× usualLancaster, 21 February: 9.7 µg/m³, 1.1× usualLancaster, 22 February: 11.3 µg/m³, 1.3× usualRedfordRedford, 11 February: no readingRedford, 12 February: 8.3 µg/m³, 0.7× usualRedford, 13 February: 23.7 µg/m³, 2.0× usualRedford, 14 February: 26.8 µg/m³, 2.2× usualRedford, 15 February: 37.9 µg/m³, 3.2× usualRedford, 16 February: 35.7 µg/m³, 3.0× usualRedford, 17 February: 31.9 µg/m³, 2.7× usualRedford, 18 February: 25.3 µg/m³, 2.1× usualRedford, 19 February: 13.3 µg/m³, 1.1× usualRedford, 20 February: 14.4 µg/m³, 1.2× usualRedford, 21 February: 9.8 µg/m³, 0.8× usualRedford, 22 February: 8.2 µg/m³, 0.7× usualWheatonWheaton, 11 February: 9.2 µg/m³, 0.9× usualWheaton, 12 February: 16.9 µg/m³, 1.6× usualWheaton, 13 February: 19.1 µg/m³, 1.9× usualWheaton, 14 February: 31.5 µg/m³, 3.1× usualWheaton, 15 February: 36.7 µg/m³, 3.6× usualWheaton, 16 February: 21.9 µg/m³, 2.1× usualWheaton, 17 February: 26.1 µg/m³, 2.5× usualWheaton, 18 February: 11.6 µg/m³, 1.1× usualWheaton, 19 February: 7.7 µg/m³, 0.7× usualWheaton, 20 February: 10.1 µg/m³, 1.0× usualWheaton, 21 February: 12.3 µg/m³, 1.2× usualWheaton, 22 February: 2.9 µg/m³, 0.3× usualLondonLondon, 11 February: 3.0 µg/m³, 0.4× usualLondon, 12 February: 2.7 µg/m³, 0.4× usualLondon, 13 February: 10.9 µg/m³, 1.5× usualLondon, 14 February: 36.1 µg/m³, 4.9× usualLondon, 15 February: 30.1 µg/m³, 4.1× usualLondon, 16 February: 25.1 µg/m³, 3.4× usualLondon, 17 February: 24.2 µg/m³, 3.3× usualLondon, 18 February: 16.0 µg/m³, 2.2× usualLondon, 19 February: 9.9 µg/m³, 1.3× usualLondon, 20 February: 8.6 µg/m³, 1.2× usualLondon, 21 February: 6.9 µg/m³, 0.9× usualLondon, 22 February: 5.6 µg/m³, 0.8× usualWindsorWindsor, 11 February: 4.4 µg/m³, 0.5× usualWindsor, 12 February: 4.9 µg/m³, 0.5× usualWindsor, 13 February: 14.2 µg/m³, 1.6× usualWindsor, 14 February: 25.8 µg/m³, 2.8× usualWindsor, 15 February: 35.6 µg/m³, 3.9× usualWindsor, 16 February: 35.0 µg/m³, 3.8× usualWindsor, 17 February: 24.5 µg/m³, 2.7× usualWindsor, 18 February: 15.8 µg/m³, 1.7× usualWindsor, 19 February: 7.6 µg/m³, 0.8× usualWindsor, 20 February: 9.5 µg/m³, 1.0× usualWindsor, 21 February: 5.9 µg/m³, 0.6× usualWindsor, 22 February: 4.6 µg/m³, 0.5× usualMolineMoline, 11 February: 6.7 µg/m³, 1.0× usualMoline, 12 February: 8.9 µg/m³, 1.3× usualMoline, 13 February: 14.6 µg/m³, 2.2× usualMoline, 14 February: 34.5 µg/m³, 5.2× usualMoline, 15 February: 24.6 µg/m³, 3.7× usualMoline, 16 February: 11.2 µg/m³, 1.7× usualMoline, 17 February: 10.9 µg/m³, 1.7× usualMoline, 18 February: 5.5 µg/m³, 0.8× usualMoline, 19 February: 6.1 µg/m³, 0.9× usualMoline, 20 February: 5.5 µg/m³, 0.8× usualMoline, 21 February: 6.2 µg/m³, 0.9× usualMoline, 22 February: 4.6 µg/m³, 0.7× usualOconomowocOconomowoc, 11 February: 4.3 µg/m³, 0.7× usualOconomowoc, 12 February: 6.1 µg/m³, 1.0× usualOconomowoc, 13 February: 22.3 µg/m³, 3.5× usualOconomowoc, 14 February: 34.0 µg/m³, 5.3× usualOconomowoc, 15 February: 30.4 µg/m³, 4.7× usualOconomowoc, 16 February: 11.8 µg/m³, 1.8× usualOconomowoc, 17 February: 30.9 µg/m³, 4.8× usualOconomowoc, 18 February: 10.2 µg/m³, 1.6× usualOconomowoc, 19 February: 2.6 µg/m³, 0.4× usualOconomowoc, 20 February: 3.6 µg/m³, 0.6× usualOconomowoc, 21 February: 3.1 µg/m³, 0.5× usualOconomowoc, 22 February: 0.7 µg/m³, 0.1× usualCamdenCamden, 11 February: 17.1 µg/m³, 1.3× usualCamden, 12 February: 6.9 µg/m³, 0.5× usualCamden, 13 February: 15.1 µg/m³, 1.1× usualCamden, 14 February: 26.3 µg/m³, 2.0× usualCamden, 15 February: 33.1 µg/m³, 2.5× usualCamden, 16 February: no readingCamden, 17 February: 26.2 µg/m³, 2.0× usualCamden, 18 February: no readingCamden, 19 February: 21.4 µg/m³, 1.6× usualCamden, 20 February: no readingCamden, 21 February: no readingCamden, 22 February: no readingDavenportDavenport, 11 February: 8.7 µg/m³, 1.3× usualDavenport, 12 February: 7.2 µg/m³, 1.1× usualDavenport, 13 February: 13.4 µg/m³, 2.0× usualDavenport, 14 February: 32.8 µg/m³, 5.0× usualDavenport, 15 February: 23.9 µg/m³, 3.6× usualDavenport, 16 February: 10.7 µg/m³, 1.6× usualDavenport, 17 February: 9.6 µg/m³, 1.5× usualDavenport, 18 February: 5.4 µg/m³, 0.8× usualDavenport, 19 February: 5.2 µg/m³, 0.8× usualDavenport, 20 February: 5.3 µg/m³, 0.8× usualDavenport, 21 February: 5.9 µg/m³, 0.9× usualDavenport, 22 February: 4.1 µg/m³, 0.6× usualFranklin ParkFranklin Park, 11 February: 8.1 µg/m³, 1.0× usualFranklin Park, 12 February: 10.8 µg/m³, 1.3× usualFranklin Park, 13 February: 14.7 µg/m³, 1.8× usualFranklin Park, 14 February: 26.8 µg/m³, 3.2× usualFranklin Park, 15 February: 32.4 µg/m³, 3.9× usualFranklin Park, 16 February: 16.1 µg/m³, 1.9× usualFranklin Park, 17 February: 17.7 µg/m³, 2.1× usualFranklin Park, 18 February: 8.0 µg/m³, 1.0× usualFranklin Park, 19 February: 7.3 µg/m³, 0.9× usualFranklin Park, 20 February: 6.4 µg/m³, 0.8× usualFranklin Park, 21 February: 8.2 µg/m³, 1.0× usualFranklin Park, 22 February: 4.5 µg/m³, 0.5× usualElginElgin, 11 February: 7.4 µg/m³, 1.1× usualElgin, 12 February: 10.5 µg/m³, 1.6× usualElgin, 13 February: 15.0 µg/m³, 2.3× usualElgin, 14 February: 28.4 µg/m³, 4.3× usualElgin, 15 February: 31.4 µg/m³, 4.8× usualElgin, 16 February: 14.9 µg/m³, 2.3× usualElgin, 17 February: 14.7 µg/m³, 2.2× usualElgin, 18 February: 6.3 µg/m³, 1.0× usualElgin, 19 February: 7.1 µg/m³, 1.1× usualElgin, 20 February: 5.9 µg/m³, 0.9× usualElgin, 21 February: 7.2 µg/m³, 1.1× usualElgin, 22 February: 3.4 µg/m³, 0.5× usualMilwaukeeMilwaukee, 11 February: 6.4 µg/m³, 0.8× usualMilwaukee, 12 February: 6.0 µg/m³, 0.8× usualMilwaukee, 13 February: 15.2 µg/m³, 2.0× usualMilwaukee, 14 February: 31.3 µg/m³, 4.1× usualMilwaukee, 15 February: 28.3 µg/m³, 3.7× usualMilwaukee, 16 February: 15.8 µg/m³, 2.1× usualMilwaukee, 17 February: 21.1 µg/m³, 2.8× usualMilwaukee, 18 February: 8.5 µg/m³, 1.1× usualMilwaukee, 19 February: 5.1 µg/m³, 0.7× usualMilwaukee, 20 February: 4.9 µg/m³, 0.6× usualMilwaukee, 21 February: 4.7 µg/m³, 0.6× usualMilwaukee, 22 February: 2.8 µg/m³, 0.4× usualSt. ThomasSt. Thomas, 11 February: 3.1 µg/m³, 0.5× usualSt. Thomas, 12 February: 2.2 µg/m³, 0.3× usualSt. Thomas, 13 February: 8.8 µg/m³, 1.3× usualSt. Thomas, 14 February: 30.6 µg/m³, 4.6× usualSt. Thomas, 15 February: 26.3 µg/m³, 4.0× usualSt. Thomas, 16 February: 19.8 µg/m³, 3.0× usualSt. Thomas, 17 February: 16.4 µg/m³, 2.5× usualSt. Thomas, 18 February: 12.6 µg/m³, 1.9× usualSt. Thomas, 19 February: 8.6 µg/m³, 1.3× usualSt. Thomas, 20 February: 6.3 µg/m³, 1.0× usualSt. Thomas, 21 February: 6.8 µg/m³, 1.0× usualSt. Thomas, 22 February: 4.9 µg/m³, 0.7× usualClintonClinton, 11 February: 7.6 µg/m³, 1.0× usualClinton, 12 February: 10.8 µg/m³, 1.4× usualClinton, 13 February: 15.0 µg/m³, 2.0× usualClinton, 14 February: 30.2 µg/m³, 4.0× usualClinton, 15 February: 21.3 µg/m³, 2.8× usualClinton, 16 February: 10.7 µg/m³, 1.4× usualClinton, 17 February: 12.1 µg/m³, 1.6× usualClinton, 18 February: 5.7 µg/m³, 0.8× usualClinton, 19 February: 5.1 µg/m³, 0.7× usualClinton, 20 February: 5.4 µg/m³, 0.7× usualClinton, 21 February: 5.5 µg/m³, 0.7× usualClinton, 22 February: 4.1 µg/m³, 0.5× usualWaukeshaWaukesha, 11 February: 6.2 µg/m³, 0.8× usualWaukesha, 12 February: 6.9 µg/m³, 0.9× usualWaukesha, 13 February: 17.1 µg/m³, 2.3× usualWaukesha, 14 February: 30.1 µg/m³, 4.0× usualWaukesha, 15 February: 29.3 µg/m³, 3.9× usualWaukesha, 16 February: 15.3 µg/m³, 2.0× usualWaukesha, 17 February: 20.6 µg/m³, 2.7× usualWaukesha, 18 February: 7.4 µg/m³, 1.0× usualWaukesha, 19 February: 4.8 µg/m³, 0.6× usualWaukesha, 20 February: 4.4 µg/m³, 0.6× usualWaukesha, 21 February: 4.8 µg/m³, 0.6× usualWaukesha, 22 February: 2.9 µg/m³, 0.4× usualIowa CityIowa City, 11 February: 9.1 µg/m³, 1.3× usualIowa City, 12 February: 12.4 µg/m³, 1.7× usualIowa City, 13 February: 13.4 µg/m³, 1.9× usualIowa City, 14 February: 29.9 µg/m³, 4.2× usualIowa City, 15 February: 19.2 µg/m³, 2.7× usualIowa City, 16 February: 10.2 µg/m³, 1.4× usualIowa City, 17 February: 10.0 µg/m³, 1.4× usualIowa City, 18 February: 8.1 µg/m³, 1.1× usualIowa City, 19 February: 4.6 µg/m³, 0.6× usualIowa City, 20 February: 6.4 µg/m³, 0.9× usualIowa City, 21 February: 5.8 µg/m³, 0.8× usualIowa City, 22 February: 4.4 µg/m³, 0.6× usualRockfordRockford, 11 February: 8.3 µg/m³, 1.2× usualRockford, 12 February: 11.0 µg/m³, 1.5× usualRockford, 13 February: 19.7 µg/m³, 2.8× usualRockford, 14 February: 29.8 µg/m³, 4.2× usualRockford, 15 February: 27.7 µg/m³, 3.9× usualRockford, 16 February: 15.7 µg/m³, 2.2× usualRockford, 17 February: 13.4 µg/m³, 1.9× usualRockford, 18 February: 5.4 µg/m³, 0.8× usualRockford, 19 February: 5.8 µg/m³, 0.8× usualRockford, 20 February: 4.9 µg/m³, 0.7× usualRockford, 21 February: 5.7 µg/m³, 0.8× usualRockford, 22 February: 3.3 µg/m³, 0.5× usualReadingReading, 11 February: 14.3 µg/m³, 1.9× usualReading, 12 February: 3.2 µg/m³, 0.4× usualReading, 13 February: 7.8 µg/m³, 1.0× usualReading, 14 February: 20.1 µg/m³, 2.6× usualReading, 15 February: 33.6 µg/m³, 4.4× usualReading, 16 February: 13.6 µg/m³, 1.8× usualReading, 17 February: 30.5 µg/m³, 4.0× usualReading, 18 February: 44.8 µg/m³, 5.9× usualReading, 19 February: 17.1 µg/m³, 2.3× usualReading, 20 February: 8.7 µg/m³, 1.1× usualReading, 21 February: 7.0 µg/m³, 0.9× usualReading, 22 February: 7.7 µg/m³, 1.0× usualSouthfieldSouthfield, 11 February: 3.6 µg/m³, 0.6× usualSouthfield, 12 February: 3.9 µg/m³, 0.6× usualSouthfield, 13 February: 12.9 µg/m³, 2.1× usualSouthfield, 14 February: 23.2 µg/m³, 3.8× usualSouthfield, 15 February: 43.5 µg/m³, 7.1× usualSouthfield, 16 February: 33.9 µg/m³, 5.6× usualSouthfield, 17 February: 26.1 µg/m³, 4.3× usualSouthfield, 18 February: 19.3 µg/m³, 3.2× usualSouthfield, 19 February: 8.0 µg/m³, 1.3× usualSouthfield, 20 February: 8.2 µg/m³, 1.3× usualSouthfield, 21 February: 5.1 µg/m³, 0.8× usualSouthfield, 22 February: 3.9 µg/m³, 0.6× usualDetroitDetroit, 11 February: 5.0 µg/m³, 0.6× usualDetroit, 12 February: 5.5 µg/m³, 0.6× usualDetroit, 13 February: 18.0 µg/m³, 2.0× usualDetroit, 14 February: 24.3 µg/m³, 2.7× usualDetroit, 15 February: 38.3 µg/m³, 4.3× usualDetroit, 16 February: 42.0 µg/m³, 4.7× usualDetroit, 17 February: 25.7 µg/m³, 2.9× usualDetroit, 18 February: 17.9 µg/m³, 2.0× usualDetroit, 19 February: 7.9 µg/m³, 0.9× usualDetroit, 20 February: 9.0 µg/m³, 1.0× usualDetroit, 21 February: 5.5 µg/m³, 0.6× usualDetroit, 22 February: 4.5 µg/m³, 0.5× usualYorkYork, 11 February: 18.5 µg/m³, 2.4× usualYork, 12 February: 6.2 µg/m³, 0.8× usualYork, 13 February: 10.6 µg/m³, 1.4× usualYork, 14 February: 20.3 µg/m³, 2.6× usualYork, 15 February: 39.0 µg/m³, 5.0× usualYork, 16 February: 23.4 µg/m³, 3.0× usualYork, 17 February: 27.7 µg/m³, 3.6× usualYork, 18 February: 30.9 µg/m³, 4.0× usualYork, 19 February: 32.3 µg/m³, 4.1× usualYork, 20 February: 14.3 µg/m³, 1.8× usualYork, 21 February: 14.8 µg/m³, 1.9× usualYork, 22 February: 14.8 µg/m³, 1.9× usualDearbornDearborn, 11 February: 4.4 µg/m³, 0.5× usualDearborn, 12 February: 5.1 µg/m³, 0.5× usualDearborn, 13 February: 12.3 µg/m³, 1.3× usualDearborn, 14 February: 20.8 µg/m³, 2.2× usualDearborn, 15 February: 38.7 µg/m³, 4.0× usualDearborn, 16 February: 34.1 µg/m³, 3.6× usualDearborn, 17 February: 24.3 µg/m³, 2.5× usualDearborn, 18 February: 18.2 µg/m³, 1.9× usualDearborn, 19 February: 9.1 µg/m³, 0.9× usualDearborn, 20 February: 8.4 µg/m³, 0.9× usualDearborn, 21 February: 5.4 µg/m³, 0.6× usualDearborn, 22 February: 4.3 µg/m³, 0.4× usualEastpointeEastpointe, 11 February: 3.8 µg/m³, 0.5× usualEastpointe, 12 February: 3.9 µg/m³, 0.5× usualEastpointe, 13 February: 13.4 µg/m³, 1.7× usualEastpointe, 14 February: 23.9 µg/m³, 3.1× usualEastpointe, 15 February: 38.3 µg/m³, 5.0× usualEastpointe, 16 February: 34.1 µg/m³, 4.4× usualEastpointe, 17 February: 22.8 µg/m³, 3.0× usualEastpointe, 18 February: 16.5 µg/m³, 2.1× usualEastpointe, 19 February: 7.0 µg/m³, 0.9× usualEastpointe, 20 February: 7.7 µg/m³, 1.0× usualEastpointe, 21 February: 5.2 µg/m³, 0.7× usualEastpointe, 22 February: 4.5 µg/m³, 0.6× usualSarniaSarnia, 11 February: 3.5 µg/m³, 0.5× usualSarnia, 12 February: 5.0 µg/m³, 0.8× usualSarnia, 13 February: 15.3 µg/m³, 2.3× usualSarnia, 14 February: 23.3 µg/m³, 3.5× usualSarnia, 15 February: 38.0 µg/m³, 5.8× usualSarnia, 16 February: 26.4 µg/m³, 4.0× usualSarnia, 17 February: 22.7 µg/m³, 3.4× usualSarnia, 18 February: 17.0 µg/m³, 2.6× usualSarnia, 19 February: 10.5 µg/m³, 1.6× usualSarnia, 20 February: 7.5 µg/m³, 1.1× usualSarnia, 21 February: 3.6 µg/m³, 0.5× usualSarnia, 22 February: 3.0 µg/m³, 0.5× usualHarrisburgHarrisburg, 11 February: 11.8 µg/m³, 1.4× usualHarrisburg, 12 February: 3.7 µg/m³, 0.4× usualHarrisburg, 13 February: 7.0 µg/m³, 0.8× usualHarrisburg, 14 February: 18.9 µg/m³, 2.2× usualHarrisburg, 15 February: 37.8 µg/m³, 4.5× usualHarrisburg, 16 February: 18.5 µg/m³, 2.2× usualHarrisburg, 17 February: 27.5 µg/m³, 3.3× usualHarrisburg, 18 February: 34.8 µg/m³, 4.1× usualHarrisburg, 19 February: 28.4 µg/m³, 3.4× usualHarrisburg, 20 February: 9.3 µg/m³, 1.1× usualHarrisburg, 21 February: 6.4 µg/m³, 0.8× usualHarrisburg, 22 February: 9.2 µg/m³, 1.1× usualAnn ArborAnn Arbor, 11 February: 5.8 µg/m³, 0.8× usualAnn Arbor, 12 February: 5.9 µg/m³, 0.8× usualAnn Arbor, 13 February: 16.0 µg/m³, 2.3× usualAnn Arbor, 14 February: 18.6 µg/m³, 2.7× usualAnn Arbor, 15 February: 36.0 µg/m³, 5.1× usualAnn Arbor, 16 February: no readingAnn Arbor, 17 February: 29.3 µg/m³, 4.2× usualAnn Arbor, 18 February: 25.8 µg/m³, 3.7× usualAnn Arbor, 19 February: no readingAnn Arbor, 20 February: 14.5 µg/m³, 2.1× usualAnn Arbor, 21 February: 6.2 µg/m³, 0.9× usualAnn Arbor, 22 February: no readingCarlisleCarlisle, 11 February: 12.5 µg/m³, 1.6× usualCarlisle, 12 February: 3.8 µg/m³, 0.5× usualCarlisle, 13 February: 6.1 µg/m³, 0.8× usualCarlisle, 14 February: 16.1 µg/m³, 2.1× usualCarlisle, 15 February: 35.8 µg/m³, 4.6× usualCarlisle, 16 February: 19.2 µg/m³, 2.5× usualCarlisle, 17 February: 25.7 µg/m³, 3.3× usualCarlisle, 18 February: 35.3 µg/m³, 4.6× usualCarlisle, 19 February: 27.8 µg/m³, 3.6× usualCarlisle, 20 February: 9.1 µg/m³, 1.2× usualCarlisle, 21 February: 6.0 µg/m³, 0.8× usualCarlisle, 22 February: 7.7 µg/m³, 1.0× usualLincoln ParkLincoln Park, 11 February: 4.6 µg/m³, 0.5× usualLincoln Park, 12 February: 4.3 µg/m³, 0.4× usualLincoln Park, 13 February: 12.5 µg/m³, 1.3× usualLincoln Park, 14 February: 21.2 µg/m³, 2.1× usualLincoln Park, 15 February: 35.7 µg/m³, 3.6× usualLincoln Park, 16 February: 34.6 µg/m³, 3.5× usualLincoln Park, 17 February: 28.1 µg/m³, 2.8× usualLincoln Park, 18 February: 21.3 µg/m³, 2.2× usualLincoln Park, 19 February: 12.2 µg/m³, 1.2× usualLincoln Park, 20 February: 9.2 µg/m³, 0.9× usualLincoln Park, 21 February: 5.4 µg/m³, 0.5× usualLincoln Park, 22 February: 4.5 µg/m³, 0.5× usualGrand RapidsGrand Rapids, 11 February: 4.8 µg/m³, 0.6× usualGrand Rapids, 12 February: 8.4 µg/m³, 1.0× usualGrand Rapids, 13 February: 13.3 µg/m³, 1.6× usualGrand Rapids, 14 February: 22.2 µg/m³, 2.7× usualGrand Rapids, 15 February: 35.1 µg/m³, 4.3× usualGrand Rapids, 16 February: 29.0 µg/m³, 3.6× usualGrand Rapids, 17 February: 26.1 µg/m³, 3.2× usualGrand Rapids, 18 February: 16.6 µg/m³, 2.0× usualGrand Rapids, 19 February: 6.7 µg/m³, 0.8× usualGrand Rapids, 20 February: 7.7 µg/m³, 1.0× usualGrand Rapids, 21 February: 4.6 µg/m³, 0.6× usualGrand Rapids, 22 February: 2.4 µg/m³, 0.3× usualBethlehemBethlehem, 11 February: 12.4 µg/m³, 1.9× usualBethlehem, 12 February: 4.0 µg/m³, 0.6× usualBethlehem, 13 February: 7.8 µg/m³, 1.2× usualBethlehem, 14 February: 19.1 µg/m³, 3.0× usualBethlehem, 15 February: 26.9 µg/m³, 4.2× usualBethlehem, 16 February: 10.7 µg/m³, 1.7× usualBethlehem, 17 February: 24.2 µg/m³, 3.8× usualBethlehem, 18 February: 33.4 µg/m³, 5.2× usualBethlehem, 19 February: 11.2 µg/m³, 1.7× usualBethlehem, 20 February: 6.8 µg/m³, 1.1× usualBethlehem, 21 February: 6.2 µg/m³, 1.0× usualBethlehem, 22 February: 8.4 µg/m³, 1.3× usualTaylorTaylor, 11 February: 3.9 µg/m³, 0.5× usualTaylor, 12 February: 4.3 µg/m³, 0.5× usualTaylor, 13 February: 12.5 µg/m³, 1.6× usualTaylor, 14 February: 19.1 µg/m³, 2.4× usualTaylor, 15 February: 32.7 µg/m³, 4.1× usualTaylor, 16 February: 31.3 µg/m³, 3.9× usualTaylor, 17 February: 25.0 µg/m³, 3.1× usualTaylor, 18 February: 16.8 µg/m³, 2.1× usualTaylor, 19 February: 8.2 µg/m³, 1.0× usualTaylor, 20 February: 8.0 µg/m³, 1.0× usualTaylor, 21 February: 4.8 µg/m³, 0.6× usualTaylor, 22 February: 4.5 µg/m³, 0.6× usualOregonOregon, 11 February: 6.7 µg/m³, 0.7× usualOregon, 12 February: 7.5 µg/m³, 0.8× usualOregon, 13 February: 21.6 µg/m³, 2.3× usualOregon, 14 February: 16.9 µg/m³, 1.8× usualOregon, 15 February: 32.5 µg/m³, 3.5× usualOregon, 16 February: 29.7 µg/m³, 3.2× usualOregon, 17 February: 27.0 µg/m³, 2.9× usualOregon, 18 February: 16.4 µg/m³, 1.8× usualOregon, 19 February: 7.1 µg/m³, 0.8× usualOregon, 20 February: 14.8 µg/m³, 1.6× usualOregon, 21 February: 10.9 µg/m³, 1.2× usualOregon, 22 February: 4.9 µg/m³, 0.5× usualWilmingtonWilmington, 11 February: 15.9 µg/m³, 2.1× usualWilmington, 12 February: 4.4 µg/m³, 0.6× usualWilmington, 13 February: 9.7 µg/m³, 1.3× usualWilmington, 14 February: 20.7 µg/m³, 2.8× usualWilmington, 15 February: 32.3 µg/m³, 4.3× usualWilmington, 16 February: 11.5 µg/m³, 1.5× usualWilmington, 17 February: 22.2 µg/m³, 3.0× usualWilmington, 18 February: 29.1 µg/m³, 3.9× usualWilmington, 19 February: 19.9 µg/m³, 2.7× usualWilmington, 20 February: 9.3 µg/m³, 1.2× usualWilmington, 21 February: 10.9 µg/m³, 1.5× usualWilmington, 22 February: 6.9 µg/m³, 0.9× usualElmwood ParkElmwood Park, 11 February: 7.8 µg/m³, 1.1× usualElmwood Park, 12 February: 8.9 µg/m³, 1.2× usualElmwood Park, 13 February: 13.8 µg/m³, 1.9× usualElmwood Park, 14 February: 24.1 µg/m³, 3.3× usualElmwood Park, 15 February: 32.0 µg/m³, 4.4× usualElmwood Park, 16 February: 16.1 µg/m³, 2.2× usualElmwood Park, 17 February: 18.0 µg/m³, 2.5× usualElmwood Park, 18 February: 8.1 µg/m³, 1.1× usualElmwood Park, 19 February: 7.6 µg/m³, 1.0× usualElmwood Park, 20 February: 6.3 µg/m³, 0.9× usualElmwood Park, 21 February: 8.0 µg/m³, 1.1× usualElmwood Park, 22 February: 3.5 µg/m³, 0.5× usualAuroraAurora, 11 February: 6.6 µg/m³, 1.0× usualAurora, 12 February: 10.9 µg/m³, 1.7× usualAurora, 13 February: 12.2 µg/m³, 1.9× usualAurora, 14 February: 24.4 µg/m³, 3.8× usualAurora, 15 February: 30.8 µg/m³, 4.8× usualAurora, 16 February: 12.8 µg/m³, 2.0× usualAurora, 17 February: 12.9 µg/m³, 2.0× usualAurora, 18 February: 6.0 µg/m³, 0.9× usualAurora, 19 February: 7.4 µg/m³, 1.2× usualAurora, 20 February: 5.2 µg/m³, 0.8× usualAurora, 21 February: 6.0 µg/m³, 0.9× usualAurora, 22 February: 3.2 µg/m³, 0.5× usualChathamChatham, 11 February: 3.6 µg/m³, 0.5× usualChatham, 12 February: 3.4 µg/m³, 0.5× usualChatham, 13 February: 11.3 µg/m³, 1.7× usualChatham, 14 February: 22.6 µg/m³, 3.4× usualChatham, 15 February: 30.8 µg/m³, 4.7× usualChatham, 16 February: 20.5 µg/m³, 3.1× usualChatham, 17 February: 20.9 µg/m³, 3.2× usualChatham, 18 February: 14.5 µg/m³, 2.2× usualChatham, 19 February: 7.1 µg/m³, 1.1× usualChatham, 20 February: 6.8 µg/m³, 1.0× usualChatham, 21 February: 5.5 µg/m³, 0.8× usualChatham, 22 February: 5.2 µg/m³, 0.8× usualChesterChester, 11 February: 14.3 µg/m³, 2.0× usualChester, 12 February: 3.9 µg/m³, 0.5× usualChester, 13 February: 9.1 µg/m³, 1.3× usualChester, 14 February: 19.4 µg/m³, 2.7× usualChester, 15 February: 30.8 µg/m³, 4.3× usualChester, 16 February: 10.4 µg/m³, 1.5× usualChester, 17 February: 18.6 µg/m³, 2.6× usualChester, 18 February: 23.3 µg/m³, 3.3× usualChester, 19 February: 17.5 µg/m³, 2.5× usualChester, 20 February: 8.9 µg/m³, 1.3× usualChester, 21 February: 10.0 µg/m³, 1.4× usualChester, 22 February: 7.0 µg/m³, 1.0× usualYpsilantiYpsilanti, 11 February: 4.6 µg/m³, 0.6× usualYpsilanti, 12 February: 4.8 µg/m³, 0.6× usualYpsilanti, 13 February: 12.8 µg/m³, 1.6× usualYpsilanti, 14 February: 16.4 µg/m³, 2.1× usualYpsilanti, 15 February: 30.8 µg/m³, 3.9× usualYpsilanti, 16 February: 25.6 µg/m³, 3.2× usualYpsilanti, 17 February: 23.9 µg/m³, 3.0× usualYpsilanti, 18 February: 17.9 µg/m³, 2.2× usualYpsilanti, 19 February: 11.2 µg/m³, 1.4× usualYpsilanti, 20 February: 10.2 µg/m³, 1.3× usualYpsilanti, 21 February: 4.4 µg/m³, 0.6× usualYpsilanti, 22 February: 3.8 µg/m³, 0.5× usualPennsaukenPennsauken, 11 February: 15.3 µg/m³, 2.0× usualPennsauken, 12 February: 5.1 µg/m³, 0.7× usualPennsauken, 13 February: 11.1 µg/m³, 1.5× usualPennsauken, 14 February: 23.2 µg/m³, 3.1× usualPennsauken, 15 February: 30.7 µg/m³, 4.0× usualPennsauken, 16 February: 12.6 µg/m³, 1.7× usualPennsauken, 17 February: 26.5 µg/m³, 3.5× usualPennsauken, 18 February: 30.0 µg/m³, 3.9× usualPennsauken, 19 February: 15.5 µg/m³, 2.0× usualPennsauken, 20 February: 8.9 µg/m³, 1.2× usualPennsauken, 21 February: 11.4 µg/m³, 1.5× usualPennsauken, 22 February: 7.0 µg/m³, 0.9× usualEvanstonEvanston, 11 February: 8.4 µg/m³, 1.1× usualEvanston, 12 February: 9.6 µg/m³, 1.3× usualEvanston, 13 February: 15.7 µg/m³, 2.1× usualEvanston, 14 February: 20.4 µg/m³, 2.7× usualEvanston, 15 February: 30.5 µg/m³, 4.1× usualEvanston, 16 February: 26.5 µg/m³, 3.5× usualEvanston, 17 February: 18.5 µg/m³, 2.5× usualEvanston, 18 February: 10.5 µg/m³, 1.4× usualEvanston, 19 February: 4.0 µg/m³, 0.5× usualEvanston, 20 February: 8.7 µg/m³, 1.2× usualEvanston, 21 February: 12.5 µg/m³, 1.7× usualEvanston, 22 February: 2.7 µg/m³, 0.4× usualNepeanNepean, 11 February: 18.0 µg/m³, 3.6× usualNepean, 12 February: 1.4 µg/m³, 0.3× usualNepean, 13 February: 3.4 µg/m³, 0.7× usualNepean, 14 February: 15.0 µg/m³, 3.0× usualNepean, 15 February: 1.6 µg/m³, 0.3× usualNepean, 16 February: 16.8 µg/m³, 3.4× usualNepean, 17 February: 54.0 µg/m³, 11× usualNepean, 18 February: 9.4 µg/m³, 1.9× usualNepean, 19 February: 8.6 µg/m³, 1.7× usualNepean, 20 February: 5.7 µg/m³, 1.1× usualNepean, 21 February: 2.6 µg/m³, 0.5× usualNepean, 22 February: 6.8 µg/m³, 1.4× usualGatineauGatineau, 11 February: 8.8 µg/m³, 1.7× usualGatineau, 12 February: 1.3 µg/m³, 0.3× usualGatineau, 13 February: 1.4 µg/m³, 0.3× usualGatineau, 14 February: 9.4 µg/m³, 1.8× usualGatineau, 15 February: 1.3 µg/m³, 0.3× usualGatineau, 16 February: 12.1 µg/m³, 2.3× usualGatineau, 17 February: 47.3 µg/m³, 9.1× usualGatineau, 18 February: 5.1 µg/m³, 1.0× usualGatineau, 19 February: 4.4 µg/m³, 0.8× usualGatineau, 20 February: 3.3 µg/m³, 0.6× usualGatineau, 21 February: 2.9 µg/m³, 0.6× usualGatineau, 22 February: 4.1 µg/m³, 0.8× usualTorontoToronto, 11 February: 4.9 µg/m³, 0.7× usualToronto, 12 February: 4.0 µg/m³, 0.6× usualToronto, 13 February: 9.3 µg/m³, 1.4× usualToronto, 14 February: 18.0 µg/m³, 2.7× usualToronto, 15 February: 8.5 µg/m³, 1.3× usualToronto, 16 February: 18.8 µg/m³, 2.8× usualToronto, 17 February: 37.2 µg/m³, 5.6× usualToronto, 18 February: 8.0 µg/m³, 1.2× usualToronto, 19 February: 5.2 µg/m³, 0.8× usualToronto, 20 February: 7.7 µg/m³, 1.1× usualToronto, 21 February: 7.8 µg/m³, 1.2× usualToronto, 22 February: 8.4 µg/m³, 1.3× usualCornwallCornwall, 11 February: 9.9 µg/m³, 1.5× usualCornwall, 12 February: 2.5 µg/m³, 0.4× usualCornwall, 13 February: 4.8 µg/m³, 0.7× usualCornwall, 14 February: 9.5 µg/m³, 1.5× usualCornwall, 15 February: 3.2 µg/m³, 0.5× usualCornwall, 16 February: 14.9 µg/m³, 2.3× usualCornwall, 17 February: 35.9 µg/m³, 5.5× usualCornwall, 18 February: 10.8 µg/m³, 1.7× usualCornwall, 19 February: 7.1 µg/m³, 1.1× usualCornwall, 20 February: 9.5 µg/m³, 1.5× usualCornwall, 21 February: 4.2 µg/m³, 0.6× usualCornwall, 22 February: 7.1 µg/m³, 1.1× usualMiltonMilton, 11 February: 5.9 µg/m³, 0.9× usualMilton, 12 February: 4.5 µg/m³, 0.7× usualMilton, 13 February: 9.0 µg/m³, 1.3× usualMilton, 14 February: 17.8 µg/m³, 2.6× usualMilton, 15 February: 11.1 µg/m³, 1.6× usualMilton, 16 February: 21.0 µg/m³, 3.1× usualMilton, 17 February: 33.7 µg/m³, 5.0× usualMilton, 18 February: 11.6 µg/m³, 1.7× usualMilton, 19 February: 5.0 µg/m³, 0.7× usualMilton, 20 February: 7.2 µg/m³, 1.1× usualMilton, 21 February: 7.4 µg/m³, 1.1× usualMilton, 22 February: 9.2 µg/m³, 1.4× usualNewmarketNewmarket, 11 February: 3.0 µg/m³, 0.5× usualNewmarket, 12 February: 2.8 µg/m³, 0.5× usualNewmarket, 13 February: 7.8 µg/m³, 1.4× usualNewmarket, 14 February: 14.2 µg/m³, 2.5× usualNewmarket, 15 February: 10.0 µg/m³, 1.8× usualNewmarket, 16 February: 21.5 µg/m³, 3.8× usualNewmarket, 17 February: 33.5 µg/m³, 5.9× usualNewmarket, 18 February: 8.3 µg/m³, 1.5× usualNewmarket, 19 February: 5.3 µg/m³, 0.9× usualNewmarket, 20 February: 6.8 µg/m³, 1.2× usualNewmarket, 21 February: 4.9 µg/m³, 0.9× usualNewmarket, 22 February: 7.5 µg/m³, 1.3× usualAlbanyAlbany, 11 February: 19.2 µg/m³, 3.2× usualAlbany, 12 February: 4.4 µg/m³, 0.7× usualAlbany, 13 February: 9.3 µg/m³, 1.6× usualAlbany, 14 February: 20.5 µg/m³, 3.4× usualAlbany, 15 February: 18.9 µg/m³, 3.2× usualAlbany, 16 February: 9.5 µg/m³, 1.6× usualAlbany, 17 February: 32.9 µg/m³, 5.5× usualAlbany, 18 February: 33.3 µg/m³, 5.6× usualAlbany, 19 February: 15.4 µg/m³, 2.6× usualAlbany, 20 February: 9.3 µg/m³, 1.6× usualAlbany, 21 February: 14.0 µg/m³, 2.3× usualAlbany, 22 February: 10.8 µg/m³, 1.8× usualNew York CityNew York City, 11 February: 13.3 µg/m³, 2.0× usualNew York City, 12 February: 3.5 µg/m³, 0.5× usualNew York City, 13 February: 5.8 µg/m³, 0.9× usualNew York City, 14 February: 15.9 µg/m³, 2.4× usualNew York City, 15 February: 19.2 µg/m³, 2.9× usualNew York City, 16 February: 6.5 µg/m³, 1.0× usualNew York City, 17 February: 27.9 µg/m³, 4.2× usualNew York City, 18 February: 31.6 µg/m³, 4.8× usualNew York City, 19 February: 10.0 µg/m³, 1.5× usualNew York City, 20 February: 6.1 µg/m³, 0.9× usualNew York City, 21 February: 6.9 µg/m³, 1.0× usualNew York City, 22 February: 5.9 µg/m³, 0.9× usualMississaugaMississauga, 11 February: 5.3 µg/m³, 0.9× usualMississauga, 12 February: 4.3 µg/m³, 0.7× usualMississauga, 13 February: 7.5 µg/m³, 1.3× usualMississauga, 14 February: 16.5 µg/m³, 2.8× usualMississauga, 15 February: 8.6 µg/m³, 1.5× usualMississauga, 16 February: 18.2 µg/m³, 3.1× usualMississauga, 17 February: 31.2 µg/m³, 5.3× usualMississauga, 18 February: 10.8 µg/m³, 1.8× usualMississauga, 19 February: 4.1 µg/m³, 0.7× usualMississauga, 20 February: 7.0 µg/m³, 1.2× usualMississauga, 21 February: 7.7 µg/m³, 1.3× usualMississauga, 22 February: 8.2 µg/m³, 1.4× usualOakvilleOakville, 11 February: 5.5 µg/m³, 0.9× usualOakville, 12 February: 4.4 µg/m³, 0.7× usualOakville, 13 February: 7.2 µg/m³, 1.2× usualOakville, 14 February: 17.0 µg/m³, 2.7× usualOakville, 15 February: 10.3 µg/m³, 1.7× usualOakville, 16 February: 18.6 µg/m³, 3.0× usualOakville, 17 February: 31.2 µg/m³, 5.0× usualOakville, 18 February: 11.1 µg/m³, 1.8× usualOakville, 19 February: 5.3 µg/m³, 0.9× usualOakville, 20 February: 7.7 µg/m³, 1.2× usualOakville, 21 February: 8.5 µg/m³, 1.4× usualOakville, 22 February: 8.6 µg/m³, 1.4× usualHartfordHartford, 11 February: 16.0 µg/m³, 2.7× usualHartford, 12 February: 3.4 µg/m³, 0.6× usualHartford, 13 February: 4.5 µg/m³, 0.8× usualHartford, 14 February: 17.0 µg/m³, 2.9× usualHartford, 15 February: 19.9 µg/m³, 3.4× usualHartford, 16 February: 6.4 µg/m³, 1.1× usualHartford, 17 February: 30.0 µg/m³, 5.1× usualHartford, 18 February: 30.0 µg/m³, 5.1× usualHartford, 19 February: 6.1 µg/m³, 1.0× usualHartford, 20 February: 8.2 µg/m³, 1.4× usualHartford, 21 February: 5.3 µg/m³, 0.9× usualHartford, 22 February: 5.6 µg/m³, 0.9× usualLebanonLebanon, 11 February: 13.6 µg/m³, 1.7× usualLebanon, 12 February: 3.3 µg/m³, 0.4× usualLebanon, 13 February: 7.8 µg/m³, 1.0× usualLebanon, 14 February: no readingLebanon, 15 February: no readingLebanon, 16 February: no readingLebanon, 17 February: no readingLebanon, 18 February: 44.2 µg/m³, 5.4× usualLebanon, 19 February: 24.9 µg/m³, 3.0× usualLebanon, 20 February: 9.7 µg/m³, 1.2× usualLebanon, 21 February: 7.7 µg/m³, 0.9× usualLebanon, 22 February: 8.5 µg/m³, 1.0× usualNewtonNewton, 11 February: 13.7 µg/m³, 2.7× usualNewton, 12 February: no readingNewton, 13 February: 0.8 µg/m³, 0.2× usualNewton, 14 February: 12.6 µg/m³, 2.5× usualNewton, 15 February: 13.1 µg/m³, 2.6× usualNewton, 16 February: 4.0 µg/m³, 0.8× usualNewton, 17 February: 21.9 µg/m³, 4.4× usualNewton, 18 February: 35.9 µg/m³, 7.2× usualNewton, 19 February: 0.5 µg/m³, 0.1× usualNewton, 20 February: 1.4 µg/m³, 0.3× usualNewton, 21 February: 7.1 µg/m³, 1.4× usualNewton, 22 February: 8.9 µg/m³, 1.8× usualAllentownAllentown, 11 February: 12.1 µg/m³, 1.9× usualAllentown, 12 February: 4.1 µg/m³, 0.6× usualAllentown, 13 February: 8.0 µg/m³, 1.2× usualAllentown, 14 February: 18.0 µg/m³, 2.8× usualAllentown, 15 February: 24.5 µg/m³, 3.8× usualAllentown, 16 February: 10.9 µg/m³, 1.7× usualAllentown, 17 February: 24.8 µg/m³, 3.8× usualAllentown, 18 February: 35.3 µg/m³, 5.4× usualAllentown, 19 February: 11.0 µg/m³, 1.7× usualAllentown, 20 February: 7.1 µg/m³, 1.1× usualAllentown, 21 February: 5.9 µg/m³, 0.9× usualAllentown, 22 February: 6.0 µg/m³, 0.9× usualLexingtonLexington, 11 February: 12.1 µg/m³, 2.4× usualLexington, 12 February: 0.9 µg/m³, 0.2× usualLexington, 13 February: no readingLexington, 14 February: 9.2 µg/m³, 1.8× usualLexington, 15 February: 11.2 µg/m³, 2.2× usualLexington, 16 February: 5.6 µg/m³, 1.1× usualLexington, 17 February: 20.8 µg/m³, 4.2× usualLexington, 18 February: 32.9 µg/m³, 6.6× usualLexington, 19 February: 1.5 µg/m³, 0.3× usualLexington, 20 February: 1.9 µg/m³, 0.4× usualLexington, 21 February: 5.8 µg/m³, 1.2× usualLexington, 22 February: 8.6 µg/m³, 1.7× usualDanburyDanbury, 11 February: 14.4 µg/m³, 2.5× usualDanbury, 12 February: 3.1 µg/m³, 0.5× usualDanbury, 13 February: 4.8 µg/m³, 0.8× usualDanbury, 14 February: 13.7 µg/m³, 2.4× usualDanbury, 15 February: 19.6 µg/m³, 3.4× usualDanbury, 16 February: 6.0 µg/m³, 1.1× usualDanbury, 17 February: 23.9 µg/m³, 4.2× usualDanbury, 18 February: 32.0 µg/m³, 5.6× usualDanbury, 19 February: 6.2 µg/m³, 1.1× usualDanbury, 20 February: 4.6 µg/m³, 0.8× usualDanbury, 21 February: 4.3 µg/m³, 0.8× usualDanbury, 22 February: 4.7 µg/m³, 0.8× usualElizabethElizabeth, 11 February: 10.9 µg/m³, 1.4× usualElizabeth, 12 February: 2.4 µg/m³, 0.3× usualElizabeth, 13 February: 3.1 µg/m³, 0.4× usualElizabeth, 14 February: 11.3 µg/m³, 1.5× usualElizabeth, 15 February: 19.0 µg/m³, 2.5× usualElizabeth, 16 February: 6.0 µg/m³, 0.8× usualElizabeth, 17 February: 24.2 µg/m³, 3.1× usualElizabeth, 18 February: 31.7 µg/m³, 4.1× usualElizabeth, 19 February: 10.1 µg/m³, 1.3× usualElizabeth, 20 February: 6.3 µg/m³, 0.8× usualElizabeth, 21 February: 6.6 µg/m³, 0.9× usualElizabeth, 22 February: 5.4 µg/m³, 0.7× usualPatersonPaterson, 11 February: 10.5 µg/m³, 2.1× usualPaterson, 12 February: 2.5 µg/m³, 0.5× usualPaterson, 13 February: 4.1 µg/m³, 0.8× usualPaterson, 14 February: 12.2 µg/m³, 2.4× usualPaterson, 15 February: 15.4 µg/m³, 3.0× usualPaterson, 16 February: 5.6 µg/m³, 1.1× usualPaterson, 17 February: 20.0 µg/m³, 3.9× usualPaterson, 18 February: 30.5 µg/m³, 6.0× usualPaterson, 19 February: 8.3 µg/m³, 1.6× usualPaterson, 20 February: 4.7 µg/m³, 0.9× usualPaterson, 21 February: 4.6 µg/m³, 0.9× usualPaterson, 22 February: 4.9 µg/m³, 1.0× usualSpringfieldSpringfield, 11 February: 9.5 µg/m³, 1.5× usualSpringfield, 12 February: 3.2 µg/m³, 0.5× usualSpringfield, 13 February: 3.8 µg/m³, 0.6× usualSpringfield, 14 February: 13.0 µg/m³, 2.0× usualSpringfield, 15 February: 14.6 µg/m³, 2.3× usualSpringfield, 16 February: 6.6 µg/m³, 1.0× usualSpringfield, 17 February: 23.9 µg/m³, 3.7× usualSpringfield, 18 February: 29.8 µg/m³, 4.7× usualSpringfield, 19 February: 4.2 µg/m³, 0.7× usualSpringfield, 20 February: 6.1 µg/m³, 1.0× usualSpringfield, 21 February: 4.7 µg/m³, 0.7× usualSpringfield, 22 February: 5.8 µg/m³, 0.9× usual11 Feb1315171921
The 60 cities with the highest readings of 96, 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
NepeanOntario, Canada1 54.017 February4.511×
GatineauQuebec, Canada1 47.317 February5.29.1×
NewtonMassachusetts, United States1 35.918 February3.47.2×
SouthfieldMichigan, United States3 43.515 February6.17.1×
LexingtonMassachusetts, United States1 32.918 February3.66.6×
LancasterPennsylvania, United States4 54.315 February8.56.4×
PatersonNew Jersey, United States1 30.518 February5.16.0×
ReadingPennsylvania, United States3 44.818 February7.65.9×
NewmarketOntario, Canada1 33.517 February5.75.9×
SarniaOntario, Canada2 38.015 February6.65.8×
DanburyConnecticut, United States1 32.018 February5.75.6×
AllistonOntario, Canada1 27.917 February4.35.6×
TorontoOntario, Canada1 37.217 February6.75.6×
AlbanyNew York, United States2 33.318 February6.05.6×
CornwallOntario, Canada1 35.917 February6.55.5×
SyracuseNew York, United States1 27.517 February4.95.5×
AllentownPennsylvania, United States1 35.318 February6.55.4×
LebanonPennsylvania, United States1 44.218 February8.25.4×
KingstonOntario, Canada1 26.717 February4.65.3×
OconomowocWisconsin, United States3 34.014 February6.45.3×
MississaugaOntario, Canada1 31.217 February5.95.3×
MolineIllinois, United States1 34.514 February6.65.2×
BethlehemPennsylvania, United States2 33.418 February6.45.2×
Ann ArborMichigan, United States2 36.015 February7.05.1×
BarrieOntario, Canada1 28.817 February5.65.1×
BellevilleOntario, Canada1 25.517 February5.05.1×
HartfordConnecticut, United States2 30.017 February5.95.1×
OakvilleOntario, Canada1 31.217 February6.25.0×
YorkPennsylvania, United States4 39.015 February7.85.0×
EastpointeMichigan, United States2 38.315 February7.75.0×
DavenportIowa, United States1 32.814 February6.65.0×
MiltonOntario, Canada1 33.717 February6.85.0×
Jersey CityNew Jersey, United States1 27.618 February5.64.9×
BramptonOntario, Canada1 28.317 February5.84.9×
LondonOntario, Canada3 36.114 February7.44.9×
WaterburyConnecticut, United States1 29.018 February6.04.8×
AuroraIllinois, United States1 30.815 February6.44.8×
New York CityNew York, United States2 31.618 February6.64.8×
ElginIllinois, United States2 31.415 February6.64.8×
Port HuronMichigan, United States2 34.915 February7.44.7×
DetroitMichigan, United States3 42.016 February9.04.7×
ChathamOntario, Canada1 30.815 February6.64.7×
SpringfieldMassachusetts, United States1 29.818 February6.44.7×
CarlislePennsylvania, United States4 35.815 February7.74.6×
St. ThomasOntario, Canada2 30.614 February6.64.6×
OttawaOntario, Canada1 26.317 February5.84.5×
Fort LeeNew Jersey, United States1 29.418 February6.54.5×
HarrisburgPennsylvania, United States4 37.815 February8.44.5×
Elmwood ParkIllinois, United States1 32.015 February7.34.4×
GuelphOntario, Canada1 27.617 February6.34.4×
WaterdownOntario, Canada1 27.517 February6.34.4×
ChesterPennsylvania, United States1 30.815 February7.14.3×
Grand RapidsMichigan, United States3 35.115 February8.14.3×
WilmingtonDelaware, United States2 32.315 February7.54.3×
KitchenerOntario, Canada1 28.817 February6.74.3×
Des PlainesIllinois, United States1 29.515 February6.94.3×
State CollegePennsylvania, United States1 27.716 February6.54.3×
LindenNew Jersey, United States1 27.918 February6.64.2×
EriePennsylvania, United States1 26.115 February6.24.2×
RockfordIllinois, United States2 29.814 February7.14.2×
Iowa CityIowa, United States1 29.914 February7.24.2×
LansingMichigan, United States2 29.015 February7.04.1×
NorristownPennsylvania, United States2 29.415 February7.14.1×
MilwaukeeWisconsin, United States2 31.314 February7.64.1×
ElizabethNew Jersey, United States1 31.718 February7.74.1×
TaylorMichigan, United States3 32.715 February8.04.1×
Cedar RapidsIowa, United States1 25.714 February6.34.1×
EvanstonIllinois, United States2 30.515 February7.54.1×
PennsaukenNew Jersey, United States3 30.715 February7.64.0×
DearbornMichigan, United States2 38.715 February9.64.0×
ClintonIowa, United States1 30.214 February7.54.0×
WaukeshaWisconsin, United States2 30.114 February7.54.0×
HamiltonOntario, Canada1 27.217 February6.84.0×
WindsorOntario, Canada3 35.615 February9.13.9×
Franklin ParkIllinois, United States2 32.415 February8.33.9×
YpsilantiMichigan, United States2 30.815 February8.03.9×
PawtucketRhode Island, United States1 25.918 February6.83.8×
HollandMichigan, United States1 26.515 February7.13.7×
Lincoln ParkMichigan, United States3 35.715 February9.93.6×
ElkhartIndiana, United States1 27.615 February7.73.6×
WheatonIllinois, United States2 36.715 February10.33.6×
KalamazooMichigan, United States2 29.716 February8.43.5×
OregonOhio, United States3 32.515 February9.33.5×
BrookfieldIllinois, United States1 28.015 February8.13.5×
DoltonIllinois, United States1 29.315 February8.53.4×
Bay CityMichigan, United States2 28.915 February8.53.4×
ChicagoIllinois, United States1 26.415 February7.83.4×
PhiladelphiaPennsylvania, United States2 27.215 February8.13.4×
South MilwaukeeWisconsin, United States1 26.214 February8.13.2×
WyomingMichigan, United States1 28.615 February9.03.2×
ToledoOhio, United States3 27.915 February8.83.2×
RedfordMichigan, United States4 37.915 February12.03.2×
Evergreen ParkIllinois, United States1 26.115 February9.72.7×
CamdenNew Jersey, United States1 33.115 February13.32.5×
AbingtonPennsylvania, United States1 29.215 February13.32.2×
SkokieIllinois, United States1 29.215 February13.62.1×

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 12 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, February 2026: 96 cities with PM2.5 at twice their usual or more, 14 to 19 February 2026, smogrank.com/episodes/2026-02-north-eastern-united-states-and-canada-2 (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.