SmogRank / Episodes / United States

North-eastern United States, March 2025

For 1 day, on 15 March 2025, 54 cities in the United States had PM2.5 at least twice their usual for the time of year. The worst reading was East Saint Louis, Illinois, United States: 70.1 µg/m³ on 15 March, about 9.2× its usual 7.6.

No cause namedWe have no fire or smoke records for these days, so we only say what the measurements show.
Cities reached54in 1 country
Days115 March 2025
Worst day15 March54 cities counted
Furthest above usual12×Lemay

Day by day

15 March 54 cities at twice their usual or more
ArnoldColumbiaDyersburgBartlettHernandoPaducahJacksonFort SmithRaymoreLeawoodLibertyKansas CityKansas CityOlatheEvansvilleClarksvilleSaint JosephOwensboroMuscatineColumbiaJacksonTopekaShreveportNashvilleMolineDavenportIowa CityJasperTerre HauteHendersonvilleDecaturCedar RapidsDes MoinesClintonAnkenyHuntsvillePonca CityBloomingtonHueytownDerbyWaterlooBirminghamElizabethtownWichitaValley StationTrussvilleHattiesburgNew AlbanyAuroraLouisvilleJeffersonvilleEdmondRockfordNapervilleSaint MatthewsOklahoma CityMooreCookevilleBellevueColumbusJeffersontownIndianapolisElginGadsdenOmahaLa VistaFranklin ParkBaton RougeCaryFishersDes PlainesChattanoogaLincolnEast RidgeLafayetteKokomoMadisonAndersonZionSulphurMontgomeryGulfportKennerPrichardNew OrleansChalmetteOconomowocMuncieWaukeshaPascagoulaLawtonSouth MilwaukeeMilwaukeeFairhopePort ArthurRochesterFerry PassWest PensacolaFort WayneMankatoMidwayColumbusGrand IslandEau ClaireApple ValleyKalamazooBurnsvilleShakopeeSaint PaulMinneapolisSioux FallsGreen BayBlaineSaint MichaelAustinBrookingsSan MarcosWatertownLive OakBaytownMission BendHoustonPasadenaMissouri CityJenksLa PorteJolietConroeCollege StationOak LawnSaginawElmwood ParkCalumet CityTulsaHammondDoltonBrookfieldChicagoEast ChicagoTaylorWyomingSpringfieldPeoriaMcAlesterLafayetteBloomingtonGalvestonDentonElkhartNorthbrookGarySouth BendTexarkanaAppletonSpringfieldGrand RapidsSpringdaleBeltonCorsicanaLittle RockFort WorthHollandPortageJenisonMichigan CitySt. LouisGranite CityDecaturChampaignUniversity CityUpper AltonEast Saint LouisLemay
12 Mar131415161718
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

DentonDenton, 12 March: 6.6 µg/m³, 0.9× usualDenton, 13 March: 7.1 µg/m³, 1.0× usualDenton, 14 March: 63.0 µg/m³, 9.0× usualDenton, 15 March: 31.1 µg/m³, 4.4× usualDenton, 16 March: 2.9 µg/m³, 0.4× usualDenton, 17 March: no readingDenton, 18 March: 6.2 µg/m³, 0.9× usualTulsaTulsa, 12 March: 9.9 µg/m³, 1.0× usualTulsa, 13 March: 17.8 µg/m³, 1.8× usualTulsa, 14 March: 60.9 µg/m³, 6.2× usualTulsa, 15 March: 36.8 µg/m³, 3.8× usualTulsa, 16 March: 15.1 µg/m³, 1.5× usualTulsa, 17 March: 10.1 µg/m³, 1.0× usualTulsa, 18 March: 12.0 µg/m³, 1.2× usualFort WorthFort Worth, 12 March: 9.3 µg/m³, 1.2× usualFort Worth, 13 March: 8.8 µg/m³, 1.1× usualFort Worth, 14 March: 60.1 µg/m³, 7.5× usualFort Worth, 15 March: 47.8 µg/m³, 6.0× usualFort Worth, 16 March: 3.0 µg/m³, 0.4× usualFort Worth, 17 March: 4.9 µg/m³, 0.6× usualFort Worth, 18 March: 7.3 µg/m³, 0.9× usualJenksJenks, 12 March: 10.4 µg/m³, 1.1× usualJenks, 13 March: 14.9 µg/m³, 1.6× usualJenks, 14 March: 54.2 µg/m³, 5.8× usualJenks, 15 March: 28.7 µg/m³, 3.1× usualJenks, 16 March: 4.6 µg/m³, 0.5× usualJenks, 17 March: 8.3 µg/m³, 0.9× usualJenks, 18 March: 7.7 µg/m³, 0.8× usualMcAlesterMcAlester, 12 March: 6.1 µg/m³, 0.8× usualMcAlester, 13 March: 8.2 µg/m³, 1.0× usualMcAlester, 14 March: 46.5 µg/m³, 5.9× usualMcAlester, 15 March: 34.2 µg/m³, 4.3× usualMcAlester, 16 March: 5.3 µg/m³, 0.7× usualMcAlester, 17 March: 6.1 µg/m³, 0.8× usualMcAlester, 18 March: 6.1 µg/m³, 0.8× usualSaginawSaginaw, 12 March: 7.2 µg/m³, 0.9× usualSaginaw, 13 March: 5.0 µg/m³, 0.7× usualSaginaw, 14 March: 39.1 µg/m³, 5.1× usualSaginaw, 15 March: 28.1 µg/m³, 3.7× usualSaginaw, 16 March: 4.0 µg/m³, 0.5× usualSaginaw, 17 March: 5.0 µg/m³, 0.7× usualSaginaw, 18 March: 5.7 µg/m³, 0.8× usualSpringdaleSpringdale, 12 March: 11.8 µg/m³, 1.3× usualSpringdale, 13 March: 16.0 µg/m³, 1.8× usualSpringdale, 14 March: 34.1 µg/m³, 3.8× usualSpringdale, 15 March: 51.5 µg/m³, 5.7× usualSpringdale, 16 March: 7.7 µg/m³, 0.9× usualSpringdale, 17 March: 8.2 µg/m³, 0.9× usualSpringdale, 18 March: 15.6 µg/m³, 1.7× usualConroeConroe, 12 March: 7.8 µg/m³, 0.8× usualConroe, 13 March: 14.2 µg/m³, 1.4× usualConroe, 14 March: 29.9 µg/m³, 2.9× usualConroe, 15 March: 34.7 µg/m³, 3.4× usualConroe, 16 March: 8.2 µg/m³, 0.8× usualConroe, 17 March: 23.0 µg/m³, 2.2× usualConroe, 18 March: 6.7 µg/m³, 0.7× usualMission BendMission Bend, 12 March: 5.7 µg/m³, 0.6× usualMission Bend, 13 March: 16.9 µg/m³, 1.8× usualMission Bend, 14 March: 28.0 µg/m³, 2.9× usualMission Bend, 15 March: 25.0 µg/m³, 2.6× usualMission Bend, 16 March: 3.4 µg/m³, 0.4× usualMission Bend, 17 March: 4.3 µg/m³, 0.5× usualMission Bend, 18 March: 5.4 µg/m³, 0.6× usualHoustonHouston, 12 March: 10.1 µg/m³, 0.9× usualHouston, 13 March: 19.0 µg/m³, 1.7× usualHouston, 14 March: 27.9 µg/m³, 2.4× usualHouston, 15 March: 30.9 µg/m³, 2.7× usualHouston, 16 March: 4.8 µg/m³, 0.4× usualHouston, 17 March: 9.5 µg/m³, 0.8× usualHouston, 18 March: 7.5 µg/m³, 0.7× usualPasadenaPasadena, 12 March: 7.8 µg/m³, 0.8× usualPasadena, 13 March: 17.2 µg/m³, 1.7× usualPasadena, 14 March: 26.9 µg/m³, 2.6× usualPasadena, 15 March: 28.5 µg/m³, 2.8× usualPasadena, 16 March: 5.5 µg/m³, 0.5× usualPasadena, 17 March: 8.1 µg/m³, 0.8× usualPasadena, 18 March: 6.1 µg/m³, 0.6× usualEast Saint LouisEast Saint Louis, 12 March: 15.0 µg/m³, 2.0× usualEast Saint Louis, 13 March: 21.1 µg/m³, 2.8× usualEast Saint Louis, 14 March: 13.4 µg/m³, 1.8× usualEast Saint Louis, 15 March: 70.1 µg/m³, 9.2× usualEast Saint Louis, 16 March: 4.2 µg/m³, 0.6× usualEast Saint Louis, 17 March: 6.2 µg/m³, 0.8× usualEast Saint Louis, 18 March: 6.4 µg/m³, 0.8× usualLemayLemay, 12 March: 12.1 µg/m³, 2.1× usualLemay, 13 March: 20.8 µg/m³, 3.6× usualLemay, 14 March: 10.0 µg/m³, 1.8× usualLemay, 15 March: 66.0 µg/m³, 12× usualLemay, 16 March: 2.2 µg/m³, 0.4× usualLemay, 17 March: 5.8 µg/m³, 1.0× usualLemay, 18 March: 5.4 µg/m³, 0.9× usualGranite CityGranite City, 12 March: 15.1 µg/m³, 1.9× usualGranite City, 13 March: 20.7 µg/m³, 2.6× usualGranite City, 14 March: 15.4 µg/m³, 1.9× usualGranite City, 15 March: 64.8 µg/m³, 8.0× usualGranite City, 16 March: 4.1 µg/m³, 0.5× usualGranite City, 17 March: 6.3 µg/m³, 0.8× usualGranite City, 18 March: 7.3 µg/m³, 0.9× usualSt. LouisSt. Louis, 12 March: 15.2 µg/m³, 1.9× usualSt. Louis, 13 March: 21.4 µg/m³, 2.7× usualSt. Louis, 14 March: 23.8 µg/m³, 3.0× usualSt. Louis, 15 March: 59.9 µg/m³, 7.5× usualSt. Louis, 16 March: 3.0 µg/m³, 0.4× usualSt. Louis, 17 March: 4.6 µg/m³, 0.6× usualSt. Louis, 18 March: 7.7 µg/m³, 1.0× usualUniversity CityUniversity City, 12 March: 10.9 µg/m³, 1.7× usualUniversity City, 13 March: 16.6 µg/m³, 2.5× usualUniversity City, 14 March: 10.6 µg/m³, 1.6× usualUniversity City, 15 March: 58.4 µg/m³, 8.8× usualUniversity City, 16 March: 2.8 µg/m³, 0.4× usualUniversity City, 17 March: 4.0 µg/m³, 0.6× usualUniversity City, 18 March: 5.7 µg/m³, 0.9× usualUpper AltonUpper Alton, 12 March: 12.6 µg/m³, 2.0× usualUpper Alton, 13 March: 20.5 µg/m³, 3.3× usualUpper Alton, 14 March: 13.2 µg/m³, 2.1× usualUpper Alton, 15 March: 55.6 µg/m³, 9.0× usualUpper Alton, 16 March: 3.6 µg/m³, 0.6× usualUpper Alton, 17 March: 6.0 µg/m³, 1.0× usualUpper Alton, 18 March: 7.9 µg/m³, 1.3× usualDecaturDecatur, 12 March: 13.0 µg/m³, 2.0× usualDecatur, 13 March: 15.4 µg/m³, 2.4× usualDecatur, 14 March: 13.5 µg/m³, 2.1× usualDecatur, 15 March: 51.8 µg/m³, 8.0× usualDecatur, 16 March: 6.0 µg/m³, 0.9× usualDecatur, 17 March: 5.4 µg/m³, 0.8× usualDecatur, 18 March: 7.7 µg/m³, 1.2× usualLittle RockLittle Rock, 12 March: 13.4 µg/m³, 1.5× usualLittle Rock, 13 March: 14.6 µg/m³, 1.7× usualLittle Rock, 14 March: 21.1 µg/m³, 2.4× usualLittle Rock, 15 March: 51.0 µg/m³, 5.9× usualLittle Rock, 16 March: 5.4 µg/m³, 0.6× usualLittle Rock, 17 March: 9.3 µg/m³, 1.1× usualLittle Rock, 18 March: 13.4 µg/m³, 1.5× usualChampaignChampaign, 12 March: 9.5 µg/m³, 1.6× usualChampaign, 13 March: 12.6 µg/m³, 2.2× usualChampaign, 14 March: 16.0 µg/m³, 2.8× usualChampaign, 15 March: 50.0 µg/m³, 8.6× usualChampaign, 16 March: 4.7 µg/m³, 0.8× usualChampaign, 17 March: 4.1 µg/m³, 0.7× usualChampaign, 18 March: 4.7 µg/m³, 0.8× usualMichigan CityMichigan City, 12 March: 3.7 µg/m³, 0.6× usualMichigan City, 13 March: 10.7 µg/m³, 1.7× usualMichigan City, 14 March: 10.0 µg/m³, 1.6× usualMichigan City, 15 March: 45.8 µg/m³, 7.4× usualMichigan City, 16 March: 4.2 µg/m³, 0.7× usualMichigan City, 17 March: 5.0 µg/m³, 0.8× usualMichigan City, 18 March: 4.5 µg/m³, 0.7× usualTexarkanaTexarkana, 12 March: 10.2 µg/m³, 1.1× usualTexarkana, 13 March: 11.7 µg/m³, 1.3× usualTexarkana, 14 March: 19.2 µg/m³, 2.2× usualTexarkana, 15 March: 43.4 µg/m³, 4.9× usualTexarkana, 16 March: 2.3 µg/m³, 0.3× usualTexarkana, 17 March: 5.3 µg/m³, 0.6× usualTexarkana, 18 March: 5.0 µg/m³, 0.6× usualCorsicanaCorsicana, 12 March: 5.8 µg/m³, 0.8× usualCorsicana, 13 March: 6.7 µg/m³, 0.9× usualCorsicana, 14 March: 22.9 µg/m³, 3.1× usualCorsicana, 15 March: 43.2 µg/m³, 5.9× usualCorsicana, 16 March: 2.9 µg/m³, 0.4× usualCorsicana, 17 March: 4.6 µg/m³, 0.6× usualCorsicana, 18 March: 5.3 µg/m³, 0.7× usualBeltonBelton, 12 March: 10.1 µg/m³, 1.5× usualBelton, 13 March: 9.1 µg/m³, 1.3× usualBelton, 14 March: 19.4 µg/m³, 2.8× usualBelton, 15 March: 39.8 µg/m³, 5.8× usualBelton, 16 March: 3.0 µg/m³, 0.4× usualBelton, 17 March: 6.3 µg/m³, 0.9× usualBelton, 18 March: 4.9 µg/m³, 0.7× usualHollandHolland, 12 March: 6.0 µg/m³, 1.0× usualHolland, 13 March: 11.3 µg/m³, 1.8× usualHolland, 14 March: no readingHolland, 15 March: 39.6 µg/m³, 6.3× usualHolland, 16 March: 4.5 µg/m³, 0.7× usualHolland, 17 March: 5.2 µg/m³, 0.8× usualHolland, 18 March: 7.8 µg/m³, 1.2× usualSpringfieldSpringfield, 12 March: 14.3 µg/m³, 2.0× usualSpringfield, 13 March: 21.2 µg/m³, 3.0× usualSpringfield, 14 March: 20.0 µg/m³, 2.9× usualSpringfield, 15 March: 39.4 µg/m³, 5.6× usualSpringfield, 16 March: 2.8 µg/m³, 0.4× usualSpringfield, 17 March: 4.4 µg/m³, 0.6× usualSpringfield, 18 March: 6.3 µg/m³, 0.9× usualJenisonJenison, 12 March: 3.5 µg/m³, 0.6× usualJenison, 13 March: 7.8 µg/m³, 1.4× usualJenison, 14 March: 9.6 µg/m³, 1.7× usualJenison, 15 March: 39.1 µg/m³, 6.9× usualJenison, 16 March: 3.1 µg/m³, 0.5× usualJenison, 17 March: 3.8 µg/m³, 0.7× usualJenison, 18 March: 5.2 µg/m³, 0.9× usualPortagePortage, 12 March: 3.3 µg/m³, 0.5× usualPortage, 13 March: 9.0 µg/m³, 1.5× usualPortage, 14 March: 10.3 µg/m³, 1.7× usualPortage, 15 March: 38.8 µg/m³, 6.3× usualPortage, 16 March: 5.2 µg/m³, 0.8× usualPortage, 17 March: 5.2 µg/m³, 0.8× usualPortage, 18 March: 5.5 µg/m³, 0.9× usualWyomingWyoming, 12 March: 8.9 µg/m³, 1.1× usualWyoming, 13 March: 10.3 µg/m³, 1.2× usualWyoming, 14 March: 11.6 µg/m³, 1.4× usualWyoming, 15 March: 35.0 µg/m³, 4.2× usualWyoming, 16 March: 7.2 µg/m³, 0.9× usualWyoming, 17 March: 6.0 µg/m³, 0.7× usualWyoming, 18 March: 8.4 µg/m³, 1.0× usualGrand RapidsGrand Rapids, 12 March: 3.3 µg/m³, 0.5× usualGrand Rapids, 13 March: 7.8 µg/m³, 1.3× usualGrand Rapids, 14 March: 10.1 µg/m³, 1.7× usualGrand Rapids, 15 March: 34.2 µg/m³, 5.7× usualGrand Rapids, 16 March: 3.5 µg/m³, 0.6× usualGrand Rapids, 17 March: 4.1 µg/m³, 0.7× usualGrand Rapids, 18 March: 7.8 µg/m³, 1.3× usualGaryGary, 12 March: 4.2 µg/m³, 0.6× usualGary, 13 March: 9.8 µg/m³, 1.4× usualGary, 14 March: 11.0 µg/m³, 1.6× usualGary, 15 March: 33.6 µg/m³, 4.8× usualGary, 16 March: 6.3 µg/m³, 0.9× usualGary, 17 March: no readingGary, 18 March: no readingSouth BendSouth Bend, 12 March: 5.2 µg/m³, 0.8× usualSouth Bend, 13 March: 9.0 µg/m³, 1.4× usualSouth Bend, 14 March: 9.2 µg/m³, 1.5× usualSouth Bend, 15 March: 31.0 µg/m³, 4.9× usualSouth Bend, 16 March: 2.9 µg/m³, 0.5× usualSouth Bend, 17 March: 6.4 µg/m³, 1.0× usualSouth Bend, 18 March: 4.2 µg/m³, 0.7× usualDoltonDolton, 12 March: 4.3 µg/m³, 0.6× usualDolton, 13 March: 10.8 µg/m³, 1.4× usualDolton, 14 March: 13.3 µg/m³, 1.7× usualDolton, 15 March: 30.2 µg/m³, 3.9× usualDolton, 16 March: 5.9 µg/m³, 0.8× usualDolton, 17 March: 5.7 µg/m³, 0.7× usualDolton, 18 March: 7.1 µg/m³, 0.9× usualLafayetteLafayette, 12 March: 6.5 µg/m³, 1.0× usualLafayette, 13 March: 6.6 µg/m³, 1.0× usualLafayette, 14 March: 10.6 µg/m³, 1.6× usualLafayette, 15 March: 29.6 µg/m³, 4.4× usualLafayette, 16 March: 2.8 µg/m³, 0.4× usualLafayette, 17 March: 3.0 µg/m³, 0.4× usualLafayette, 18 March: no readingBrookfieldBrookfield, 12 March: 5.9 µg/m³, 0.8× usualBrookfield, 13 March: 14.4 µg/m³, 1.9× usualBrookfield, 14 March: 14.5 µg/m³, 1.9× usualBrookfield, 15 March: 29.4 µg/m³, 3.9× usualBrookfield, 16 March: 4.4 µg/m³, 0.6× usualBrookfield, 17 March: 5.3 µg/m³, 0.7× usualBrookfield, 18 March: 6.9 µg/m³, 0.9× usualEast ChicagoEast Chicago, 12 March: 4.0 µg/m³, 0.6× usualEast Chicago, 13 March: 10.1 µg/m³, 1.4× usualEast Chicago, 14 March: 11.4 µg/m³, 1.6× usualEast Chicago, 15 March: 28.5 µg/m³, 4.1× usualEast Chicago, 16 March: 5.5 µg/m³, 0.8× usualEast Chicago, 17 March: 4.7 µg/m³, 0.7× usualEast Chicago, 18 March: 5.6 µg/m³, 0.8× usualPeoriaPeoria, 12 March: 8.9 µg/m³, 1.3× usualPeoria, 13 March: 17.1 µg/m³, 2.6× usualPeoria, 14 March: 13.8 µg/m³, 2.1× usualPeoria, 15 March: 28.3 µg/m³, 4.3× usualPeoria, 16 March: 4.4 µg/m³, 0.7× usualPeoria, 17 March: 3.7 µg/m³, 0.6× usualPeoria, 18 March: 6.8 µg/m³, 1.0× usualMissouri CityMissouri City, 12 March: 6.3 µg/m³, 0.6× usualMissouri City, 13 March: 16.6 µg/m³, 1.6× usualMissouri City, 14 March: no readingMissouri City, 15 March: 28.0 µg/m³, 2.8× usualMissouri City, 16 March: 2.9 µg/m³, 0.3× usualMissouri City, 17 March: 4.1 µg/m³, 0.4× usualMissouri City, 18 March: 5.1 µg/m³, 0.5× usualElkhartElkhart, 12 March: 4.3 µg/m³, 0.7× usualElkhart, 13 March: 7.7 µg/m³, 1.3× usualElkhart, 14 March: 8.9 µg/m³, 1.5× usualElkhart, 15 March: 27.9 µg/m³, 4.7× usualElkhart, 16 March: 3.0 µg/m³, 0.5× usualElkhart, 17 March: 8.6 µg/m³, 1.5× usualElkhart, 18 March: 5.8 µg/m³, 1.0× usualTaylorTaylor, 12 March: 6.4 µg/m³, 0.9× usualTaylor, 13 March: 12.3 µg/m³, 1.8× usualTaylor, 14 March: 19.3 µg/m³, 2.8× usualTaylor, 15 March: 27.9 µg/m³, 4.1× usualTaylor, 16 March: no readingTaylor, 17 March: 2.9 µg/m³, 0.4× usualTaylor, 18 March: 6.2 µg/m³, 0.9× usualHammondHammond, 12 March: 4.9 µg/m³, 0.7× usualHammond, 13 March: 13.4 µg/m³, 1.9× usualHammond, 14 March: 10.9 µg/m³, 1.5× usualHammond, 15 March: 27.8 µg/m³, 3.9× usualHammond, 16 March: 5.3 µg/m³, 0.7× usualHammond, 17 March: 4.4 µg/m³, 0.6× usualHammond, 18 March: 5.2 µg/m³, 0.7× usualCalumet CityCalumet City, 12 March: 4.7 µg/m³, 0.7× usualCalumet City, 13 March: 15.1 µg/m³, 2.1× usualCalumet City, 14 March: 11.2 µg/m³, 1.6× usualCalumet City, 15 March: 27.6 µg/m³, 3.8× usualCalumet City, 16 March: 5.0 µg/m³, 0.7× usualCalumet City, 17 March: 4.8 µg/m³, 0.7× usualCalumet City, 18 March: 6.2 µg/m³, 0.9× usualGalvestonGalveston, 12 March: 5.4 µg/m³, 0.9× usualGalveston, 13 March: 10.6 µg/m³, 1.7× usualGalveston, 14 March: 18.1 µg/m³, 2.9× usualGalveston, 15 March: 27.5 µg/m³, 4.4× usualGalveston, 16 March: 4.3 µg/m³, 0.7× usualGalveston, 17 March: 3.3 µg/m³, 0.5× usualGalveston, 18 March: 5.8 µg/m³, 0.9× usualChicagoChicago, 12 March: 5.0 µg/m³, 0.7× usualChicago, 13 March: 11.2 µg/m³, 1.6× usualChicago, 14 March: 12.9 µg/m³, 1.9× usualChicago, 15 March: 27.5 µg/m³, 4.0× usualChicago, 16 March: 5.1 µg/m³, 0.7× usualChicago, 17 March: 5.1 µg/m³, 0.7× usualChicago, 18 March: 6.3 µg/m³, 0.9× usualElmwood ParkElmwood Park, 12 March: 4.4 µg/m³, 0.6× usualElmwood Park, 13 March: 11.1 µg/m³, 1.6× usualElmwood Park, 14 March: 16.0 µg/m³, 2.3× usualElmwood Park, 15 March: 26.8 µg/m³, 3.8× usualElmwood Park, 16 March: 4.9 µg/m³, 0.7× usualElmwood Park, 17 March: 5.5 µg/m³, 0.8× usualElmwood Park, 18 March: 7.2 µg/m³, 1.0× usualBloomingtonBloomington, 12 March: 8.9 µg/m³, 1.5× usualBloomington, 13 March: 14.0 µg/m³, 2.3× usualBloomington, 14 March: 13.6 µg/m³, 2.3× usualBloomington, 15 March: 26.3 µg/m³, 4.4× usualBloomington, 16 March: 4.2 µg/m³, 0.7× usualBloomington, 17 March: 3.0 µg/m³, 0.5× usualBloomington, 18 March: 6.1 µg/m³, 1.0× usualJolietJoliet, 12 March: 9.0 µg/m³, 1.2× usualJoliet, 13 March: 13.9 µg/m³, 1.8× usualJoliet, 14 March: 12.9 µg/m³, 1.7× usualJoliet, 15 March: 26.2 µg/m³, 3.4× usualJoliet, 16 March: 4.8 µg/m³, 0.6× usualJoliet, 17 March: 4.6 µg/m³, 0.6× usualJoliet, 18 March: 5.9 µg/m³, 0.8× usualNorthbrookNorthbrook, 12 March: 2.5 µg/m³, 0.5× usualNorthbrook, 13 March: 6.9 µg/m³, 1.3× usualNorthbrook, 14 March: 11.0 µg/m³, 2.0× usualNorthbrook, 15 March: 26.1 µg/m³, 4.7× usualNorthbrook, 16 March: 3.9 µg/m³, 0.7× usualNorthbrook, 17 March: 4.0 µg/m³, 0.7× usualNorthbrook, 18 March: 8.1 µg/m³, 1.5× usualSpringfieldSpringfield, 12 March: 10.3 µg/m³, 1.7× usualSpringfield, 13 March: 15.1 µg/m³, 2.4× usualSpringfield, 14 March: 11.4 µg/m³, 1.8× usualSpringfield, 15 March: 26.0 µg/m³, 4.2× usualSpringfield, 16 March: 3.9 µg/m³, 0.6× usualSpringfield, 17 March: 3.5 µg/m³, 0.6× usualSpringfield, 18 March: 5.8 µg/m³, 0.9× usualCollege StationCollege Station, 12 March: 6.5 µg/m³, 0.8× usualCollege Station, 13 March: 9.1 µg/m³, 1.2× usualCollege Station, 14 March: 22.7 µg/m³, 2.9× usualCollege Station, 15 March: 26.0 µg/m³, 3.4× usualCollege Station, 16 March: 3.9 µg/m³, 0.5× usualCollege Station, 17 March: 5.1 µg/m³, 0.7× usualCollege Station, 18 March: 5.4 µg/m³, 0.7× usualBaytownBaytown, 12 March: 6.0 µg/m³, 0.5× usualBaytown, 13 March: 17.6 µg/m³, 1.4× usualBaytown, 14 March: 24.7 µg/m³, 2.0× usualBaytown, 15 March: 26.0 µg/m³, 2.1× usualBaytown, 16 March: 4.5 µg/m³, 0.4× usualBaytown, 17 March: 6.9 µg/m³, 0.6× usualBaytown, 18 March: 6.4 µg/m³, 0.5× usualAppletonAppleton, 12 March: 3.9 µg/m³, 0.8× usualAppleton, 13 March: 10.5 µg/m³, 2.1× usualAppleton, 14 March: 11.2 µg/m³, 2.2× usualAppleton, 15 March: 25.7 µg/m³, 5.1× usualAppleton, 16 March: 2.3 µg/m³, 0.5× usualAppleton, 17 March: 3.2 µg/m³, 0.6× usualAppleton, 18 March: 5.5 µg/m³, 1.1× usualOak LawnOak Lawn, 12 March: 5.3 µg/m³, 0.7× usualOak Lawn, 13 March: 12.6 µg/m³, 1.7× usualOak Lawn, 14 March: 12.4 µg/m³, 1.7× usualOak Lawn, 15 March: 25.6 µg/m³, 3.5× usualOak Lawn, 16 March: 4.6 µg/m³, 0.6× usualOak Lawn, 17 March: 4.3 µg/m³, 0.6× usualOak Lawn, 18 March: 4.6 µg/m³, 0.6× usualLa PorteLa Porte, 12 March: 5.0 µg/m³, 0.6× usualLa Porte, 13 March: 14.6 µg/m³, 1.8× usualLa Porte, 14 March: 21.8 µg/m³, 2.8× usualLa Porte, 15 March: 25.1 µg/m³, 3.2× usualLa Porte, 16 March: 3.4 µg/m³, 0.4× usualLa Porte, 17 March: 3.9 µg/m³, 0.5× usualLa Porte, 18 March: 3.7 µg/m³, 0.5× usual12 Mar131415161718
Every counted city, 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
LemayMissouri, United States1 66.015 March5.712×
East Saint LouisIllinois, United States1 70.115 March7.69.2×
DentonTexas, United States1 63.014 March7.09.0×
Upper AltonIllinois, United States1 55.615 March6.29.0×
University CityMissouri, United States1 58.415 March6.68.8×
ChampaignIllinois, United States1 50.015 March5.88.6×
Granite CityIllinois, United States1 64.815 March8.18.0×
DecaturIllinois, United States1 51.815 March6.58.0×
Fort WorthTexas, United States1 60.114 March8.07.5×
St. LouisMissouri, United States1 59.915 March8.07.5×
Michigan CityIndiana, United States1 45.815 March6.27.4×
JenisonMichigan, United States1 39.115 March5.76.9×
HollandMichigan, United States1 39.615 March6.36.3×
PortageIndiana, United States1 38.815 March6.26.3×
TulsaOklahoma, United States1 60.914 March9.86.2×
CorsicanaTexas, United States1 43.215 March7.35.9×
McAlesterOklahoma, United States1 46.514 March7.95.9×
Little RockArkansas, United States1 51.015 March8.75.9×
BeltonTexas, United States1 39.815 March6.95.8×
JenksOklahoma, United States1 54.214 March9.45.8×
SpringdaleArkansas, United States1 51.515 March9.05.7×
Grand RapidsMichigan, United States1 34.215 March6.05.7×
SpringfieldMissouri, United States1 39.415 March7.05.6×
SaginawTexas, United States1 39.114 March7.65.1×
AppletonWisconsin, United States1 25.715 March4.45.1×
South BendIndiana, United States1 31.015 March6.34.9×
TexarkanaTexas, United States1 43.415 March8.94.9×
GaryIndiana, United States1 33.615 March7.04.8×
NorthbrookIllinois, United States1 26.115 March5.54.7×
ElkhartIndiana, United States1 27.915 March5.94.7×
LafayetteIndiana, United States1 29.615 March6.74.4×
BloomingtonIllinois, United States1 26.315 March6.04.4×
GalvestonTexas, United States1 27.515 March6.34.4×
PeoriaIllinois, United States1 28.315 March6.64.3×
WyomingMichigan, United States1 35.015 March8.34.2×
SpringfieldIllinois, United States1 26.015 March6.24.2×
TaylorTexas, United States1 27.915 March6.84.1×
East ChicagoIndiana, United States1 28.515 March7.04.1×
ChicagoIllinois, United States1 27.515 March6.94.0×
DoltonIllinois, United States1 30.215 March7.73.9×
BrookfieldIllinois, United States1 29.415 March7.53.9×
HammondIndiana, United States1 27.815 March7.13.9×
Calumet CityIllinois, United States1 27.615 March7.23.8×
Elmwood ParkIllinois, United States1 26.815 March7.13.8×
Oak LawnIllinois, United States1 25.615 March7.43.5×
College StationTexas, United States1 26.015 March7.73.4×
ConroeTexas, United States1 34.715 March10.33.4×
JolietIllinois, United States1 26.215 March7.83.4×
La PorteTexas, United States1 25.115 March7.93.2×
Mission BendTexas, United States1 28.014 March9.52.9×
Missouri CityTexas, United States1 28.015 March10.12.8×
PasadenaTexas, United States1 28.515 March10.32.8×
HoustonTexas, United States1 30.915 March11.52.7×
BaytownTexas, United States1 26.015 March12.22.1×

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

Number 19 of 98 episodes in the United States since our records began, by cities reached.

Bars: cities reached; colour: the level of the episode's highest daily reading. All 98.

Use this page

SmogRank, North-eastern United States, March 2025: 54 cities with PM2.5 at twice their usual or more, 15 March 2025, smogrank.com/episodes/2025-03-north-eastern-united-states (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.