SmogRank / Episodes / United States

Northern United States, July 2025

For 3 days, from 20 to 22 July 2025, 47 cities in the United States had PM2.5 at least twice their usual for the time of year. The worst reading was Virginia, Minnesota, United States: 45.0 µg/m³ on 20 July, about 4.5× its usual 10.1. Ended 22 July.

No cause namedWe have no fire or smoke records for these days, so we only say what the measurements show.
Cities reached47in 1 country
Days320 to 22 July 2025
Worst day21 July35 cities counted
Furthest above usual4.9×Brainerd

Day by day

21 July 35 cities at twice their usual or more
OconomowocWaukeshaAppletonClintonGreen BayMolineDavenportBraidwoodCalumet CityMuscatineHammondEast ChicagoPeoriaGaryCedar RapidsIowa CityBloomingtonPortageMichigan CityWaterlooChampaignManisteeSavoyDecaturSpringfieldSouth BendElkhartLafayetteMarquetteJerseyvilleTerre HauteKokomoApple ValleyBurnsvilleUpper AltonWood RiverColumbia CityAnkenyGranite CityShakopeeDes MoinesUniversity CityEast Saint LouisSt. LouisFishersFort WayneLemayMcCordsvilleAndersonMankatoSaint MichaelArnoldLansingFort DodgeBloomingtonMuncieColumbiaColumbusJasperSaint CloudBay CityTecumsehAnn ArborLimaYpsilantiToledoNew AlbanyJeffersonvilleLouisvilleSault Ste. MarieRedfordValley StationSaint MatthewsDentTaylorWhite OakDaytonSouthfieldJeffersontownDearbornLincoln ParkKearneySharonvilleCincinnatiMasonNorwoodLebanonDetroitFort ThomasLibertyHighland HeightsWindsorSpringfieldEastpointeSaint JosephMarshallKansas CityNew BaltimoreKansas CityRaymoreLeawoodBellevueOmahaOlathePort HuronDublinSarniaBlairLa VistaLexington-FayetteWestervilleColumbusGahannaChathamNew AlbanySioux FallsTopekaBrookingsLincolnMedinaBeatriceFlatwoodsAshlandHuntingtonWest FargoDoltonWyomingMiddletownBridgeviewElmwood ParkRochesterWarrenvilleAuroraNapervilleWheelersburgPortsmouthMinneapolisOak LawnJolietIndianapolisSaint PaulMilwaukeeElginTomahKalamazooBrookfieldChicagoJenisonHudsonvilleBlaineHollandGrand RapidsLincolnwoodSouth MilwaukeeNorthbrookGreendaleFranklin ParkCaryMadisonRockfordEau ClaireAltoonaZionWinthrop HarborDetroit LakesDes PlainesSuperiorBarabooVirginiaDuluthCloquetBrainerd
17 Jul1819202122232425
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

VirginiaVirginia, 17 July: 13.6 µg/m³Virginia, 18 July: 8.0 µg/m³Virginia, 19 July: 18.4 µg/m³Virginia, 20 July: 45.0 µg/m³, 4.5× its usual 10.1Virginia, 21 July: 24.3 µg/m³Virginia, 22 July: 16.7 µg/m³Virginia, 23 July: 5.3 µg/m³Virginia, 24 July: no readingVirginia, 25 July: 42.1 µg/m³DuluthDuluth, 17 July: 7.2 µg/m³Duluth, 18 July: 7.8 µg/m³Duluth, 19 July: 5.1 µg/m³Duluth, 20 July: 44.7 µg/m³, 4.6× its usual 9.7Duluth, 21 July: 19.3 µg/m³Duluth, 22 July: 14.5 µg/m³Duluth, 23 July: 5.9 µg/m³Duluth, 24 July: 54.4 µg/m³Duluth, 25 July: 59.7 µg/m³SuperiorSuperior, 17 July: 9.0 µg/m³Superior, 18 July: 8.3 µg/m³Superior, 19 July: 5.9 µg/m³Superior, 20 July: 41.2 µg/m³, 4.0× its usual 10.4Superior, 21 July: 17.5 µg/m³Superior, 22 July: 13.6 µg/m³Superior, 23 July: 13.2 µg/m³Superior, 24 July: 4.7 µg/m³Superior, 25 July: 22.9 µg/m³BrainerdBrainerd, 17 July: 3.5 µg/m³Brainerd, 18 July: 4.0 µg/m³Brainerd, 19 July: 4.5 µg/m³Brainerd, 20 July: 40.8 µg/m³, 4.9× its usual 8.3Brainerd, 21 July: 26.1 µg/m³, 3.1× its usual 8.4Brainerd, 22 July: 15.5 µg/m³Brainerd, 23 July: 4.5 µg/m³Brainerd, 24 July: 55.1 µg/m³Brainerd, 25 July: 42.9 µg/m³CloquetCloquet, 17 July: 5.7 µg/m³Cloquet, 18 July: 6.4 µg/m³Cloquet, 19 July: 4.6 µg/m³Cloquet, 20 July: 38.0 µg/m³, 4.9× its usual 7.7Cloquet, 21 July: 21.9 µg/m³Cloquet, 22 July: 13.3 µg/m³Cloquet, 23 July: 4.7 µg/m³Cloquet, 24 July: 59.5 µg/m³Cloquet, 25 July: 58.1 µg/m³Detroit LakesDetroit Lakes, 17 July: 3.1 µg/m³Detroit Lakes, 18 July: 3.9 µg/m³Detroit Lakes, 19 July: 9.6 µg/m³Detroit Lakes, 20 July: 33.6 µg/m³, 3.9× its usual 8.6Detroit Lakes, 21 July: 20.6 µg/m³Detroit Lakes, 22 July: 6.3 µg/m³Detroit Lakes, 23 July: 13.6 µg/m³Detroit Lakes, 24 July: 56.2 µg/m³Detroit Lakes, 25 July: 15.3 µg/m³Elmwood ParkElmwood Park, 17 July: 2.8 µg/m³Elmwood Park, 18 July: 7.6 µg/m³Elmwood Park, 19 July: 10.3 µg/m³Elmwood Park, 20 July: 11.8 µg/m³Elmwood Park, 21 July: 41.9 µg/m³, 2.3× its usual 18.3Elmwood Park, 22 July: 34.5 µg/m³Elmwood Park, 23 July: 23.0 µg/m³Elmwood Park, 24 July: 12.1 µg/m³Elmwood Park, 25 July: 9.7 µg/m³Des PlainesDes Plaines, 17 July: 3.3 µg/m³Des Plaines, 18 July: 5.9 µg/m³Des Plaines, 19 July: 8.1 µg/m³Des Plaines, 20 July: 9.3 µg/m³Des Plaines, 21 July: 39.6 µg/m³, 4.0× its usual 10.0Des Plaines, 22 July: 25.0 µg/m³, 2.6× its usual 9.8Des Plaines, 23 July: 18.9 µg/m³Des Plaines, 24 July: 11.6 µg/m³Des Plaines, 25 July: 7.7 µg/m³RockfordRockford, 17 July: 3.5 µg/m³Rockford, 18 July: 3.9 µg/m³Rockford, 19 July: 4.4 µg/m³Rockford, 20 July: 6.4 µg/m³Rockford, 21 July: 38.9 µg/m³, 3.7× its usual 10.6Rockford, 22 July: 22.3 µg/m³Rockford, 23 July: 18.1 µg/m³Rockford, 24 July: 7.0 µg/m³Rockford, 25 July: 4.5 µg/m³Franklin ParkFranklin Park, 17 July: 4.9 µg/m³Franklin Park, 18 July: 7.6 µg/m³Franklin Park, 19 July: 7.5 µg/m³Franklin Park, 20 July: 8.8 µg/m³Franklin Park, 21 July: 38.6 µg/m³, 3.3× its usual 11.8Franklin Park, 22 July: 29.0 µg/m³, 2.5× its usual 11.8Franklin Park, 23 July: 20.0 µg/m³Franklin Park, 24 July: 12.6 µg/m³Franklin Park, 25 July: 6.7 µg/m³LincolnwoodLincolnwood, 17 July: 3.1 µg/m³Lincolnwood, 18 July: 6.0 µg/m³Lincolnwood, 19 July: 7.4 µg/m³Lincolnwood, 20 July: 8.4 µg/m³Lincolnwood, 21 July: 35.2 µg/m³, 3.0× its usual 11.8Lincolnwood, 22 July: 26.8 µg/m³, 2.3× its usual 11.8Lincolnwood, 23 July: 18.8 µg/m³Lincolnwood, 24 July: 10.7 µg/m³Lincolnwood, 25 July: 5.8 µg/m³ElginElgin, 17 July: 3.8 µg/m³Elgin, 18 July: 4.5 µg/m³Elgin, 19 July: 5.2 µg/m³Elgin, 20 July: 6.1 µg/m³Elgin, 21 July: 35.0 µg/m³, 2.7× its usual 13.1Elgin, 22 July: 24.2 µg/m³Elgin, 23 July: 17.2 µg/m³Elgin, 24 July: 9.5 µg/m³Elgin, 25 July: 4.5 µg/m³CaryCary, 17 July: 3.5 µg/m³Cary, 18 July: 4.4 µg/m³Cary, 19 July: 6.0 µg/m³Cary, 20 July: 7.0 µg/m³Cary, 21 July: 34.9 µg/m³, 3.6× its usual 9.6Cary, 22 July: 21.3 µg/m³Cary, 23 July: 17.1 µg/m³Cary, 24 July: 9.8 µg/m³Cary, 25 July: 4.8 µg/m³BarabooBaraboo, 17 July: 2.7 µg/m³Baraboo, 18 July: 2.9 µg/m³Baraboo, 19 July: 3.9 µg/m³Baraboo, 20 July: 8.5 µg/m³Baraboo, 21 July: 34.2 µg/m³, 4.3× its usual 7.9Baraboo, 22 July: 13.8 µg/m³Baraboo, 23 July: 10.1 µg/m³Baraboo, 24 July: 3.9 µg/m³Baraboo, 25 July: 8.7 µg/m³AltoonaAltoona, 17 July: 2.6 µg/m³Altoona, 18 July: 3.6 µg/m³Altoona, 19 July: 5.0 µg/m³Altoona, 20 July: 12.6 µg/m³Altoona, 21 July: 33.4 µg/m³, 3.8× its usual 8.8Altoona, 22 July: 12.3 µg/m³Altoona, 23 July: 6.9 µg/m³Altoona, 24 July: 5.2 µg/m³Altoona, 25 July: 44.4 µg/m³Eau ClaireEau Claire, 17 July: 2.6 µg/m³Eau Claire, 18 July: 3.6 µg/m³Eau Claire, 19 July: 5.0 µg/m³Eau Claire, 20 July: 12.6 µg/m³Eau Claire, 21 July: 33.4 µg/m³, 3.8× its usual 8.9Eau 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/m³KalamazooKalamazoo, 17 July: 2.7 µg/m³Kalamazoo, 18 July: 4.1 µg/m³Kalamazoo, 19 July: 5.6 µg/m³Kalamazoo, 20 July: 5.5 µg/m³Kalamazoo, 21 July: 33.4 µg/m³, 2.8× its usual 11.8Kalamazoo, 22 July: 14.4 µg/m³Kalamazoo, 23 July: 11.7 µg/m³Kalamazoo, 24 July: 11.3 µg/m³Kalamazoo, 25 July: 5.3 µg/m³NorthbrookNorthbrook, 17 July: 1.9 µg/m³Northbrook, 18 July: 3.0 µg/m³Northbrook, 19 July: 5.1 µg/m³Northbrook, 20 July: 7.6 µg/m³Northbrook, 21 July: 32.1 µg/m³, 3.1× its usual 10.2Northbrook, 22 July: 18.4 µg/m³Northbrook, 23 July: 12.0 µg/m³Northbrook, 24 July: 5.5 µg/m³Northbrook, 25 July: 6.7 µg/m³MadisonMadison, 17 July: 3.0 µg/m³Madison, 18 July: 4.0 µg/m³Madison, 19 July: 4.6 µg/m³Madison, 20 July: 8.8 µg/m³Madison, 21 July: 31.1 µg/m³, 3.7× its usual 8.4Madison, 22 July: 15.7 µg/m³Madison, 23 July: 13.5 µg/m³Madison, 24 July: 3.8 µg/m³Madison, 25 July: 10.8 µg/m³Grand RapidsGrand Rapids, 17 July: 3.0 µg/m³Grand Rapids, 18 July: 4.1 µg/m³Grand Rapids, 19 July: 6.3 µg/m³Grand Rapids, 20 July: 12.2 µg/m³Grand Rapids, 21 July: 30.8 µg/m³, 3.0× its usual 10.4Grand Rapids, 22 July: 10.9 µg/m³Grand Rapids, 23 July: 12.6 µg/m³Grand Rapids, 24 July: 11.3 µg/m³Grand Rapids, 25 July: 6.6 µg/m³Winthrop HarborWinthrop Harbor, 17 July: 2.2 µg/m³Winthrop Harbor, 18 July: 3.4 µg/m³Winthrop Harbor, 19 July: 6.3 µg/m³Winthrop Harbor, 20 July: 9.2 µg/m³Winthrop Harbor, 21 July: 30.6 µg/m³, 3.9× its usual 7.8Winthrop Harbor, 22 July: 16.1 µg/m³Winthrop Harbor, 23 July: 14.1 µg/m³Winthrop Harbor, 24 July: 8.0 µg/m³Winthrop Harbor, 25 July: 10.5 µg/m³ZionZion, 17 July: 2.2 µg/m³Zion, 18 July: 3.4 µg/m³Zion, 19 July: 6.3 µg/m³Zion, 20 July: 9.2 µg/m³Zion, 21 July: 30.6 µg/m³, 3.9× its usual 7.8Zion, 22 July: 16.1 µg/m³Zion, 23 July: 14.1 µg/m³Zion, 24 July: 8.0 µg/m³Zion, 25 July: 10.5 µg/m³HudsonvilleHudsonville, 17 July: 2.4 µg/m³Hudsonville, 18 July: 4.3 µg/m³Hudsonville, 19 July: 5.9 µg/m³Hudsonville, 20 July: 8.1 µg/m³Hudsonville, 21 July: 30.0 µg/m³, 2.9× its usual 10.2Hudsonville, 22 July: 10.5 µg/m³Hudsonville, 23 July: 11.9 µg/m³Hudsonville, 24 July: 10.0 µg/m³Hudsonville, 25 July: 5.3 µg/m³JenisonJenison, 17 July: 2.4 µg/m³Jenison, 18 July: 4.3 µg/m³Jenison, 19 July: 5.9 µg/m³Jenison, 20 July: 8.1 µg/m³Jenison, 21 July: 30.0 µg/m³, 2.9× its usual 10.2Jenison, 22 July: 10.5 µg/m³Jenison, 23 July: 11.9 µg/m³Jenison, 24 July: 10.0 µg/m³Jenison, 25 July: 5.3 µg/m³BridgeviewBridgeview, 17 July: 4.3 µg/m³Bridgeview, 18 July: 9.0 µg/m³Bridgeview, 19 July: 6.0 µg/m³Bridgeview, 20 July: 8.2 µg/m³Bridgeview, 21 July: 30.0 µg/m³, 2.2× its usual 13.4Bridgeview, 22 July: 28.2 µg/m³, 2.1× its usual 13.4Bridgeview, 23 July: 17.9 µg/m³Bridgeview, 24 July: 11.0 µg/m³Bridgeview, 25 July: 8.4 µg/m³HollandHolland, 17 July: 3.6 µg/m³Holland, 18 July: 5.8 µg/m³Holland, 19 July: 7.9 µg/m³Holland, 20 July: 8.6 µg/m³Holland, 21 July: 29.8 µg/m³, 3.0× its usual 10.1Holland, 22 July: 14.5 µg/m³Holland, 23 July: 14.3 µg/m³Holland, 24 July: 14.6 µg/m³Holland, 25 July: 8.3 µg/m³ChicagoChicago, 17 July: 3.3 µg/m³Chicago, 18 July: 6.4 µg/m³Chicago, 19 July: 6.4 µg/m³Chicago, 20 July: 8.1 µg/m³Chicago, 21 July: 29.4 µg/m³, 2.9× its usual 10.1Chicago, 22 July: 27.4 µg/m³, 2.7× its usual 10.1Chicago, 23 July: 17.6 µg/m³Chicago, 24 July: 10.6 µg/m³Chicago, 25 July: 6.3 µg/m³TomahTomah, 17 July: 2.6 µg/m³Tomah, 18 July: 3.9 µg/m³Tomah, 19 July: 5.7 µg/m³Tomah, 20 July: 12.5 µg/m³Tomah, 21 July: 29.3 µg/m³, 2.8× its usual 10.5Tomah, 22 July: 12.6 µg/m³Tomah, 23 July: 8.0 µg/m³Tomah, 24 July: no readingTomah, 25 July: no readingBrookfieldBrookfield, 17 July: 3.5 µg/m³Brookfield, 18 July: 7.1 µg/m³Brookfield, 19 July: 5.3 µg/m³Brookfield, 20 July: 6.4 µg/m³Brookfield, 21 July: 28.7 µg/m³, 2.9× its usual 9.9Brookfield, 22 July: 28.1 µg/m³, 2.9× its usual 9.8Brookfield, 23 July: 16.8 µg/m³Brookfield, 24 July: 10.8 µg/m³Brookfield, 25 July: 6.5 µg/m³NapervilleNaperville, 17 July: 4.5 µg/m³Naperville, 18 July: 3.8 µg/m³Naperville, 19 July: 5.6 µg/m³Naperville, 20 July: 6.4 µg/m³Naperville, 21 July: 27.9 µg/m³, 2.4× its usual 11.5Naperville, 22 July: 26.7 µg/m³, 2.3× its usual 11.4Naperville, 23 July: 17.3 µg/m³Naperville, 24 July: 8.9 µg/m³Naperville, 25 July: 6.5 µg/m³WyomingWyoming, 17 July: 6.3 µg/m³Wyoming, 18 July: 7.6 µg/m³Wyoming, 19 July: 9.3 µg/m³Wyoming, 20 July: 11.7 µg/m³Wyoming, 21 July: 27.5 µg/m³, 2.1× its usual 13.1Wyoming, 22 July: 12.5 µg/m³Wyoming, 23 July: 14.8 µg/m³Wyoming, 24 July: 16.1 µg/m³Wyoming, 25 July: 10.2 µg/m³MilwaukeeMilwaukee, 17 July: 3.2 µg/m³Milwaukee, 18 July: 4.9 µg/m³Milwaukee, 19 July: 7.1 µg/m³Milwaukee, 20 July: 15.5 µg/m³Milwaukee, 21 July: 26.9 µg/m³, 2.6× its usual 10.2Milwaukee, 22 July: 20.2 µg/m³Milwaukee, 23 July: 16.2 µg/m³Milwaukee, 24 July: 6.9 µg/m³Milwaukee, 25 July: 20.7 µg/m³GreendaleGreendale, 17 July: 2.7 µg/m³Greendale, 18 July: 4.1 µg/m³Greendale, 19 July: 5.6 µg/m³Greendale, 20 July: 10.4 µg/m³Greendale, 21 July: 26.5 µg/m³, 3.2× its usual 8.4Greendale, 22 July: 18.1 µg/m³Greendale, 23 July: 14.9 µg/m³Greendale, 24 July: 6.6 µg/m³Greendale, 25 July: 17.6 µg/m³South MilwaukeeSouth Milwaukee, 17 July: 2.7 µg/m³South Milwaukee, 18 July: 4.1 µg/m³South Milwaukee, 19 July: 5.6 µg/m³South Milwaukee, 20 July: 10.4 µg/m³South Milwaukee, 21 July: 26.5 µg/m³, 3.1× its usual 8.5South Milwaukee, 22 July: 18.1 µg/m³South Milwaukee, 23 July: 14.9 µg/m³South Milwaukee, 24 July: 6.6 µg/m³South Milwaukee, 25 July: 17.6 µg/m³Saint PaulSaint Paul, 17 July: 2.8 µg/m³Saint Paul, 18 July: 4.3 µg/m³Saint Paul, 19 July: 6.3 µg/m³Saint Paul, 20 July: 7.8 µg/m³Saint Paul, 21 July: 26.2 µg/m³, 2.6× its usual 10.1Saint 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/m³MinneapolisMinneapolis, 17 July: 3.9 µg/m³Minneapolis, 18 July: 6.0 µg/m³Minneapolis, 19 July: 7.0 µg/m³Minneapolis, 20 July: 8.1 µg/m³Minneapolis, 21 July: 25.6 µg/m³, 2.5× its usual 10.1Minneapolis, 22 July: 13.1 µg/m³Minneapolis, 23 July: 7.4 µg/m³Minneapolis, 24 July: 15.8 µg/m³Minneapolis, 25 July: 49.3 µg/m³BlaineBlaine, 17 July: 3.2 µg/m³Blaine, 18 July: 4.7 µg/m³Blaine, 19 July: 5.3 µg/m³Blaine, 20 July: 9.4 µg/m³Blaine, 21 July: 25.5 µg/m³, 3.0× its usual 8.4Blaine, 22 July: 10.4 µg/m³Blaine, 23 July: 6.1 µg/m³Blaine, 24 July: 16.6 µg/m³Blaine, 25 July: 47.3 µg/m³AuroraAurora, 17 July: 3.9 µg/m³Aurora, 18 July: 3.9 µg/m³Aurora, 19 July: 5.0 µg/m³Aurora, 20 July: 5.0 µg/m³Aurora, 21 July: 25.3 µg/m³, 2.3× its usual 10.8Aurora, 22 July: 26.2 µg/m³, 2.4× its usual 10.8Aurora, 23 July: 16.2 µg/m³Aurora, 24 July: 8.4 µg/m³Aurora, 25 July: 5.4 µg/m³WarrenvilleWarrenville, 17 July: 3.9 µg/m³Warrenville, 18 July: 3.9 µg/m³Warrenville, 19 July: 5.0 µg/m³Warrenville, 20 July: 5.0 µg/m³Warrenville, 21 July: 25.3 µg/m³, 2.3× its usual 10.8Warrenville, 22 July: 26.2 µg/m³, 2.4× its usual 10.8Warrenville, 23 July: 16.2 µg/m³Warrenville, 24 July: 8.4 µg/m³Warrenville, 25 July: 5.4 µg/m³RochesterRochester, 17 July: 2.9 µg/m³Rochester, 18 July: 6.4 µg/m³Rochester, 19 July: 7.1 µg/m³Rochester, 20 July: 6.3 µg/m³Rochester, 21 July: 25.0 µg/m³, 2.4× its usual 10.6Rochester, 22 July: 9.9 µg/m³Rochester, 23 July: 7.0 µg/m³Rochester, 24 July: 3.8 µg/m³Rochester, 25 July: 14.1 µg/m³IndianapolisIndianapolis, 17 July: 5.3 µg/m³Indianapolis, 18 July: 5.5 µg/m³Indianapolis, 19 July: 6.7 µg/m³Indianapolis, 20 July: 6.5 µg/m³Indianapolis, 21 July: 9.7 µg/m³Indianapolis, 22 July: 27.9 µg/m³, 2.5× its usual 11.2Indianapolis, 23 July: 17.6 µg/m³Indianapolis, 24 July: 14.7 µg/m³Indianapolis, 25 July: 12.1 µg/m³JolietJoliet, 17 July: 4.4 µg/m³Joliet, 18 July: 4.8 µg/m³Joliet, 19 July: 5.2 µg/m³Joliet, 20 July: 5.5 µg/m³Joliet, 21 July: 20.5 µg/m³Joliet, 22 July: 27.5 µg/m³, 2.5× its usual 11.0Joliet, 23 July: 17.2 µg/m³Joliet, 24 July: 9.5 µg/m³Joliet, 25 July: 5.1 µg/m³DoltonDolton, 17 July: 2.9 µg/m³Dolton, 18 July: 7.9 µg/m³Dolton, 19 July: 7.0 µg/m³Dolton, 20 July: 6.6 µg/m³Dolton, 21 July: 22.1 µg/m³Dolton, 22 July: 26.9 µg/m³, 2.1× its usual 12.9Dolton, 23 July: 17.5 µg/m³Dolton, 24 July: 12.0 µg/m³Dolton, 25 July: 6.2 µg/m³MiddletownMiddletown, 17 July: 5.7 µg/m³Middletown, 18 July: no readingMiddletown, 19 July: no readingMiddletown, 20 July: no readingMiddletown, 21 July: 16.1 µg/m³Middletown, 22 July: 26.2 µg/m³, 2.2× its usual 11.9Middletown, 23 July: no readingMiddletown, 24 July: no readingMiddletown, 25 July: no readingOak LawnOak Lawn, 17 July: 3.3 µg/m³Oak Lawn, 18 July: 6.1 µg/m³Oak Lawn, 19 July: 5.4 µg/m³Oak Lawn, 20 July: 6.4 µg/m³Oak Lawn, 21 July: 24.3 µg/m³Oak Lawn, 22 July: 25.7 µg/m³, 2.5× its usual 10.3Oak Lawn, 23 July: 16.0 µg/m³Oak Lawn, 24 July: 9.4 µg/m³Oak Lawn, 25 July: 5.3 µg/m³PortsmouthPortsmouth, 17 July: 7.7 µg/m³Portsmouth, 18 July: 6.9 µg/m³Portsmouth, 19 July: 7.1 µg/m³Portsmouth, 20 July: 7.4 µg/m³Portsmouth, 21 July: 10.9 µg/m³Portsmouth, 22 July: 25.0 µg/m³, 2.5× its usual 9.9Portsmouth, 23 July: 18.0 µg/m³Portsmouth, 24 July: 15.1 µg/m³Portsmouth, 25 July: 14.5 µg/m³WheelersburgWheelersburg, 17 July: 7.7 µg/m³Wheelersburg, 18 July: 6.9 µg/m³Wheelersburg, 19 July: 7.1 µg/m³Wheelersburg, 20 July: 7.4 µg/m³Wheelersburg, 21 July: 10.9 µg/m³Wheelersburg, 22 July: 25.0 µg/m³, 2.5× its usual 10.0Wheelersburg, 23 July: 18.0 µg/m³Wheelersburg, 24 July: 15.1 µg/m³Wheelersburg, 25 July: 14.5 µg/m³17 Jul1819202122232425
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
BrainerdMinnesota, United States2 40.820 July8.34.9×
CloquetMinnesota, United States1 38.020 July7.74.9×
DuluthMinnesota, United States1 44.720 July9.74.6×
VirginiaMinnesota, United States1 45.020 July10.14.5×
BarabooWisconsin, United States1 34.221 July7.94.3×
SuperiorWisconsin, United States1 41.220 July10.44.0×
Des PlainesIllinois, United States2 39.621 July10.04.0×
Detroit LakesMinnesota, United States1 33.620 July8.63.9×
Winthrop HarborIllinois, United States1 30.621 July7.83.9×
ZionIllinois, United States1 30.621 July7.83.9×
AltoonaWisconsin, United States1 33.421 July8.83.8×
Eau ClaireWisconsin, United States1 33.421 July8.93.8×
RockfordIllinois, United States1 38.921 July10.63.7×
MadisonWisconsin, United States1 31.121 July8.43.7×
CaryIllinois, United States1 34.921 July9.63.6×
Franklin ParkIllinois, United States2 38.621 July11.83.3×
GreendaleWisconsin, United States1 26.521 July8.43.2×
NorthbrookIllinois, United States1 32.121 July10.23.1×
South MilwaukeeWisconsin, United States1 26.521 July8.53.1×
LincolnwoodIllinois, United States2 35.221 July11.83.0×
Grand RapidsMichigan, United States1 30.821 July10.43.0×
HollandMichigan, United States1 29.821 July10.13.0×
BlaineMinnesota, United States1 25.521 July8.43.0×
HudsonvilleMichigan, United States1 30.021 July10.22.9×
JenisonMichigan, United States1 30.021 July10.22.9×
ChicagoIllinois, United States2 29.421 July10.12.9×
BrookfieldIllinois, United States2 28.721 July9.92.9×
KalamazooMichigan, United States1 33.421 July11.82.8×
TomahWisconsin, United States1 29.321 July10.52.8×
ElginIllinois, United States1 35.021 July13.12.7×
MilwaukeeWisconsin, United States1 26.921 July10.22.6×
Saint PaulMinnesota, United States1 26.221 July10.12.6×
IndianapolisIndiana, United States1 27.922 July11.22.5×
JolietIllinois, United States1 27.522 July11.02.5×
Oak LawnIllinois, United States1 25.722 July10.32.5×
MinneapolisMinnesota, United States1 25.621 July10.12.5×
PortsmouthOhio, United States1 25.022 July9.92.5×
WheelersburgOhio, United States1 25.022 July10.02.5×
NapervilleIllinois, United States2 27.921 July11.52.4×
AuroraIllinois, United States2 26.222 July10.82.4×
WarrenvilleIllinois, United States2 26.222 July10.82.4×
RochesterMinnesota, United States1 25.021 July10.62.4×
Elmwood ParkIllinois, United States1 41.921 July18.32.3×
BridgeviewIllinois, United States2 30.021 July13.42.2×
MiddletownOhio, United States1 26.222 July11.92.2×
WyomingMichigan, United States1 27.521 July13.12.1×
DoltonIllinois, United States1 26.922 July12.92.1×

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

Number 30 of 151 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 151.

Use this page

SmogRank, Northern United States, July 2025: 47 cities with PM2.5 at twice their usual or more, 20 to 22 July 2025, smogrank.com/episodes/2025-07-northern-united-states (accessed 5 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.