SmogRank / Episodes / United States

Minnesota, United States, August 2024

For 2 days, from 18 to 19 August 2024, 11 cities in the United States had PM2.5 at least twice their usual for the time of year. The worst reading was Saint Cloud, Minnesota, United States: 30.0 µg/m³ on 18 August, about 3.5× 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 reached11in 1 country
Days218 to 19 August 2024
Worst day18 August9 cities counted
Furthest above usual3.6×West Fargo

Day by day

18 August 9 cities at twice their usual or more
Apple ValleyMankatoRochesterBrookingsWatertownSioux FallsAberdeenAppletonShakopeeMinneapolisBurnsvilleSaint PaulEau ClaireWest FargoSaint MichaelBlaineSaint CloudDuluthSuperior
15 Aug16171819202122
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

West FargoWest Fargo, 15 August: 1.9 µg/m³, 0.2× usualWest Fargo, 16 August: 6.8 µg/m³, 0.9× usualWest Fargo, 17 August: 29.6 µg/m³, 3.7× usualWest Fargo, 18 August: 22.8 µg/m³, 2.9× usualWest Fargo, 19 August: 25.1 µg/m³, 3.2× usualWest Fargo, 20 August: 23.3 µg/m³, 2.9× usualWest Fargo, 21 August: 17.4 µg/m³, 2.2× usualWest Fargo, 22 August: 11.4 µg/m³, 1.4× usualSaint CloudSaint Cloud, 15 August: 4.5 µg/m³, 0.5× usualSaint Cloud, 16 August: 2.7 µg/m³, 0.3× usualSaint Cloud, 17 August: 10.6 µg/m³, 1.2× usualSaint Cloud, 18 August: 30.0 µg/m³, 3.5× usualSaint Cloud, 19 August: 27.8 µg/m³, 3.3× usualSaint Cloud, 20 August: 23.3 µg/m³, 2.7× usualSaint Cloud, 21 August: 16.6 µg/m³, 2.0× usualSaint Cloud, 22 August: 7.5 µg/m³, 0.9× usualSuperiorSuperior, 15 August: 10.5 µg/m³, 1.3× usualSuperior, 16 August: 4.5 µg/m³, 0.5× usualSuperior, 17 August: 11.6 µg/m³, 1.4× usualSuperior, 18 August: 29.8 µg/m³, 3.6× usualSuperior, 19 August: 17.9 µg/m³, 2.2× usualSuperior, 20 August: 4.4 µg/m³, 0.5× usualSuperior, 21 August: 6.4 µg/m³, 0.8× usualSuperior, 22 August: 7.2 µg/m³, 0.9× usualBurnsvilleBurnsville, 15 August: 4.8 µg/m³, 0.5× usualBurnsville, 16 August: 5.2 µg/m³, 0.5× usualBurnsville, 17 August: 6.8 µg/m³, 0.7× usualBurnsville, 18 August: 28.6 µg/m³, 2.9× usualBurnsville, 19 August: 25.7 µg/m³, 2.6× usualBurnsville, 20 August: 21.7 µg/m³, 2.2× usualBurnsville, 21 August: 12.9 µg/m³, 1.3× usualBurnsville, 22 August: 7.9 µg/m³, 0.8× usualDuluthDuluth, 15 August: 9.1 µg/m³, 1.2× usualDuluth, 16 August: 4.1 µg/m³, 0.5× usualDuluth, 17 August: 12.2 µg/m³, 1.5× usualDuluth, 18 August: 27.9 µg/m³, 3.5× usualDuluth, 19 August: 17.0 µg/m³, 2.2× usualDuluth, 20 August: 4.0 µg/m³, 0.5× usualDuluth, 21 August: 6.8 µg/m³, 0.9× usualDuluth, 22 August: 7.2 µg/m³, 0.9× usualSaint PaulSaint Paul, 15 August: 4.5 µg/m³, 0.5× usualSaint Paul, 16 August: 5.1 µg/m³, 0.6× usualSaint Paul, 17 August: 7.3 µg/m³, 0.8× usualSaint Paul, 18 August: 27.9 µg/m³, 3.0× usualSaint Paul, 19 August: 25.3 µg/m³, 2.8× usualSaint Paul, 20 August: 18.3 µg/m³, 2.0× usualSaint Paul, 21 August: 10.1 µg/m³, 1.1× usualSaint Paul, 22 August: 7.3 µg/m³, 0.8× usualMinneapolisMinneapolis, 15 August: 4.6 µg/m³, 0.5× usualMinneapolis, 16 August: 4.9 µg/m³, 0.5× usualMinneapolis, 17 August: 6.7 µg/m³, 0.7× usualMinneapolis, 18 August: 27.3 µg/m³, 2.9× usualMinneapolis, 19 August: 25.2 µg/m³, 2.7× usualMinneapolis, 20 August: 19.7 µg/m³, 2.1× usualMinneapolis, 21 August: 11.8 µg/m³, 1.2× usualMinneapolis, 22 August: 7.3 µg/m³, 0.8× usualBlaineBlaine, 15 August: 4.1 µg/m³, 0.5× usualBlaine, 16 August: 3.8 µg/m³, 0.5× usualBlaine, 17 August: 6.6 µg/m³, 0.8× usualBlaine, 18 August: 26.2 µg/m³, 3.2× usualBlaine, 19 August: 24.5 µg/m³, 3.0× usualBlaine, 20 August: 17.4 µg/m³, 2.1× usualBlaine, 21 August: 11.5 µg/m³, 1.4× usualBlaine, 22 August: 7.3 µg/m³, 0.9× usualSaint MichaelSaint Michael, 15 August: 4.1 µg/m³, 0.5× usualSaint Michael, 16 August: 3.7 µg/m³, 0.4× usualSaint Michael, 17 August: 8.0 µg/m³, 0.9× usualSaint Michael, 18 August: 26.2 µg/m³, 3.1× usualSaint Michael, 19 August: 27.2 µg/m³, 3.2× usualSaint Michael, 20 August: 22.1 µg/m³, 2.6× usualSaint Michael, 21 August: 14.9 µg/m³, 1.8× usualSaint Michael, 22 August: 7.1 µg/m³, 0.8× usualShakopeeShakopee, 15 August: 4.7 µg/m³, 0.5× usualShakopee, 16 August: 4.7 µg/m³, 0.5× usualShakopee, 17 August: 8.2 µg/m³, 0.9× usualShakopee, 18 August: 25.9 µg/m³, 2.7× usualShakopee, 19 August: 27.0 µg/m³, 2.8× usualShakopee, 20 August: 21.0 µg/m³, 2.2× usualShakopee, 21 August: 14.0 µg/m³, 1.5× usualShakopee, 22 August: 7.2 µg/m³, 0.8× usualEau ClaireEau Claire, 15 August: 5.2 µg/m³, 0.7× usualEau Claire, 16 August: 4.1 µg/m³, 0.5× usualEau Claire, 17 August: 4.4 µg/m³, 0.6× usualEau Claire, 18 August: 21.3 µg/m³, 2.7× usualEau Claire, 19 August: 25.0 µg/m³, 3.2× usualEau Claire, 20 August: 8.2 µg/m³, 1.1× usualEau Claire, 21 August: 5.5 µg/m³, 0.7× usualEau Claire, 22 August: 5.9 µg/m³, 0.8× usual15 Aug16171819202122
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
West FargoNorth Dakota, United States1 29.617 August7.93.7×
SuperiorWisconsin, United States1 29.818 August8.23.6×
DuluthMinnesota, United States1 27.918 August7.93.5×
Saint CloudMinnesota, United States2 30.018 August8.53.5×
BlaineMinnesota, United States1 26.218 August8.13.2×
Eau ClaireWisconsin, United States1 25.019 August7.83.2×
Saint MichaelMinnesota, United States2 27.219 August8.53.2×
Saint PaulMinnesota, United States2 27.918 August9.23.0×
BurnsvilleMinnesota, United States2 28.618 August9.92.9×
MinneapolisMinnesota, United States2 27.318 August9.52.9×
ShakopeeMinnesota, United States2 27.019 August9.62.8×

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 92 of 131 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 131.

Use this page

SmogRank, Minnesota, United States, August 2024: 11 cities with PM2.5 at twice their usual or more, 18 to 19 August 2024, smogrank.com/episodes/2024-08-minnesota-united-states (accessed 3 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.