SmogRank / Episodes / United States

North-eastern United States and Canada around Milwaukee, 6 January 2026

For 1 day, on 6 January 2026, 16 cities in the United States and Canada had PM2.5 at least twice their usual for the time of year. The worst reading was Royal Oak, Michigan, United States: 41.2 µg/m³ on 6 January, about 6.0× its usual 6.9.

No cause namedWe have no fire or smoke records for these days, so we only say what the measurements show.
Cities reached16in 2 countries
Days16 January 2026
Worst day6 January16 cities counted
Furthest above usual6.7×Wheaton

Day by day

6 January 16 cities at twice their usual or more
ElkhartSouth BendWyomingMichigan CityLansingPortageGaryKokomoEast ChicagoHammondCalumet CityDoltonChicagoEvanstonMuncieAndersonAnn ArborLafayetteOak LawnNorthbrookBridgeviewZionYpsilantiLimaFishersPerrysburgSouth MilwaukeeToledoOregonBay CityIndianapolisJolietNapervilleCaryTaylorSouthfieldLincoln ParkAuroraDearbornWaukeshaDetroitEastpointeDaytonSpringfieldChampaignGreen BayDublinRockfordAppletonPort HuronWestervilleSarniaColumbusGahannaChathamBloomingtonMadisonMiddletonDecaturMedinaPeoriaClevelandCleveland HeightsShaker HeightsAkronClintonSpringfieldPainesvilleCantonLondonSt. ThomasMolineDavenportWarrenYoungstownMuscatineHermitageKitchenerSteubenvilleWeirtonWeirton HeightsBrantfordRedfordFranklin ParkBrookfieldDes PlainesKalamazooFort WayneElmwood ParkHollandGrand RapidsJenisonMilwaukeeElginWindsorOconomowocRoyal OakWheaton
3 Jan456789
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

Royal OakRoyal Oak, 3 January: 5.5 µg/m³Royal Oak, 4 January: 11.1 µg/m³Royal Oak, 5 January: 39.7 µg/m³Royal Oak, 6 January: 41.2 µg/m³, 6.0× its usual 6.9Royal Oak, 7 January: 29.3 µg/m³Royal Oak, 8 January: 25.4 µg/m³Royal Oak, 9 January: 5.6 µg/m³WheatonWheaton, 3 January: 9.4 µg/m³Wheaton, 4 January: 12.1 µg/m³Wheaton, 5 January: 26.8 µg/m³Wheaton, 6 January: 39.6 µg/m³, 6.7× its usual 5.9Wheaton, 7 January: 23.4 µg/m³Wheaton, 8 January: 19.4 µg/m³Wheaton, 9 January: 9.3 µg/m³OconomowocOconomowoc, 3 January: 3.1 µg/m³Oconomowoc, 4 January: 7.4 µg/m³Oconomowoc, 5 January: 26.2 µg/m³Oconomowoc, 6 January: 39.4 µg/m³, 5.0× its usual 7.9Oconomowoc, 7 January: 16.6 µg/m³Oconomowoc, 8 January: 19.0 µg/m³Oconomowoc, 9 January: 5.9 µg/m³WindsorWindsor, 3 January: 9.5 µg/m³Windsor, 4 January: 11.2 µg/m³Windsor, 5 January: 29.8 µg/m³Windsor, 6 January: 34.7 µg/m³, 3.9× its usual 9.0Windsor, 7 January: 25.8 µg/m³Windsor, 8 January: 18.2 µg/m³Windsor, 9 January: 6.8 µg/m³RedfordRedford, 3 January: no readingRedford, 4 January: no readingRedford, 5 January: no readingRedford, 6 January: 28.3 µg/m³, 2.1× its usual 13.4Redford, 7 January: 22.1 µg/m³Redford, 8 January: 19.0 µg/m³Redford, 9 January: 14.2 µg/m³Grand RapidsGrand Rapids, 3 January: 5.9 µg/m³Grand Rapids, 4 January: 5.6 µg/m³Grand Rapids, 5 January: 18.9 µg/m³Grand Rapids, 6 January: 27.8 µg/m³, 3.6× its usual 7.7Grand Rapids, 7 January: 18.8 µg/m³Grand Rapids, 8 January: 12.9 µg/m³Grand Rapids, 9 January: 3.8 µg/m³KalamazooKalamazoo, 3 January: 6.7 µg/m³Kalamazoo, 4 January: 5.9 µg/m³Kalamazoo, 5 January: 19.9 µg/m³Kalamazoo, 6 January: 27.3 µg/m³, 3.3× its usual 8.3Kalamazoo, 7 January: 18.6 µg/m³Kalamazoo, 8 January: 14.6 µg/m³Kalamazoo, 9 January: 4.6 µg/m³Franklin ParkFranklin Park, 3 January: 7.2 µg/m³Franklin Park, 4 January: 8.7 µg/m³Franklin Park, 5 January: 20.0 µg/m³Franklin Park, 6 January: 26.8 µg/m³, 3.0× its usual 8.9Franklin Park, 7 January: 14.7 µg/m³Franklin Park, 8 January: 11.8 µg/m³Franklin Park, 9 January: 6.3 µg/m³MilwaukeeMilwaukee, 3 January: 6.8 µg/m³Milwaukee, 4 January: 8.4 µg/m³Milwaukee, 5 January: 17.4 µg/m³Milwaukee, 6 January: 26.6 µg/m³, 3.8× its usual 7.0Milwaukee, 7 January: 13.0 µg/m³Milwaukee, 8 January: 14.0 µg/m³Milwaukee, 9 January: 4.3 µg/m³Elmwood ParkElmwood Park, 3 January: 6.9 µg/m³Elmwood Park, 4 January: 9.1 µg/m³Elmwood Park, 5 January: 19.1 µg/m³Elmwood Park, 6 January: 26.2 µg/m³, 3.5× its usual 7.5Elmwood Park, 7 January: 14.5 µg/m³Elmwood Park, 8 January: 11.9 µg/m³Elmwood Park, 9 January: 5.8 µg/m³Fort WayneFort Wayne, 3 January: 13.5 µg/m³Fort Wayne, 4 January: 16.7 µg/m³Fort Wayne, 5 January: 19.3 µg/m³Fort Wayne, 6 January: 26.1 µg/m³, 3.5× its usual 7.5Fort Wayne, 7 January: 17.5 µg/m³Fort Wayne, 8 January: 14.3 µg/m³Fort Wayne, 9 January: 5.0 µg/m³Des PlainesDes Plaines, 3 January: 7.2 µg/m³Des Plaines, 4 January: 9.3 µg/m³Des Plaines, 5 January: 18.0 µg/m³Des Plaines, 6 January: 26.0 µg/m³, 3.3× its usual 7.8Des Plaines, 7 January: 14.3 µg/m³Des Plaines, 8 January: 11.9 µg/m³Des Plaines, 9 January: 6.4 µg/m³JenisonJenison, 3 January: 6.4 µg/m³Jenison, 4 January: 5.7 µg/m³Jenison, 5 January: 17.1 µg/m³Jenison, 6 January: 25.8 µg/m³, 3.8× its usual 6.8Jenison, 7 January: 16.5 µg/m³Jenison, 8 January: 11.2 µg/m³Jenison, 9 January: 3.3 µg/m³ElginElgin, 3 January: 6.8 µg/m³Elgin, 4 January: 7.9 µg/m³Elgin, 5 January: 18.4 µg/m³Elgin, 6 January: 25.6 µg/m³, 3.9× its usual 6.6Elgin, 7 January: 12.3 µg/m³Elgin, 8 January: 10.5 µg/m³Elgin, 9 January: 6.3 µg/m³HollandHolland, 3 January: 6.1 µg/m³Holland, 4 January: 7.8 µg/m³Holland, 5 January: 16.9 µg/m³Holland, 6 January: 25.5 µg/m³, 3.6× its usual 7.0Holland, 7 January: 16.8 µg/m³Holland, 8 January: 11.5 µg/m³Holland, 9 January: 6.4 µg/m³BrookfieldBrookfield, 3 January: 7.7 µg/m³Brookfield, 4 January: 8.7 µg/m³Brookfield, 5 January: 19.3 µg/m³Brookfield, 6 January: 25.5 µg/m³, 3.3× its usual 7.8Brookfield, 7 January: 15.2 µg/m³Brookfield, 8 January: 12.3 µg/m³Brookfield, 9 January: 5.9 µg/m³3 Jan456789
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
WheatonIllinois, United States1 39.66 January5.96.7×
Royal OakMichigan, United States1 41.26 January6.96.0×
OconomowocWisconsin, United States1 39.46 January7.95.0×
WindsorOntario, Canada1 34.76 January9.03.9×
ElginIllinois, United States1 25.66 January6.63.9×
MilwaukeeWisconsin, United States1 26.66 January7.03.8×
JenisonMichigan, United States1 25.86 January6.83.8×
Grand RapidsMichigan, United States1 27.86 January7.73.6×
HollandMichigan, United States1 25.56 January7.03.6×
Elmwood ParkIllinois, United States1 26.26 January7.53.5×
Fort WayneIndiana, United States1 26.16 January7.53.5×
KalamazooMichigan, United States1 27.36 January8.33.3×
Des PlainesIllinois, United States1 26.06 January7.83.3×
BrookfieldIllinois, United States1 25.56 January7.83.3×
Franklin ParkIllinois, United States1 26.86 January8.93.0×
RedfordMichigan, United States1 28.36 January13.42.1×

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 and Canada

Number 67 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 around Milwaukee, 6 January 2026: 16 cities with PM2.5 at twice their usual or more, 6 January 2026, smogrank.com/episodes/2026-01-06-north-eastern-united-states-and-canada-milwaukee (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.