SmogRank / Episodes / United States
Minnesota and South Dakota, United States, August 2023
For 2 days, from 29 to 30 August 2023, 14 cities in the United States had PM2.5 at least twice their usual for the time of year. The worst reading was Bismarck, North Dakota, United States: 64.5 µg/m³ on 29 August, about 5.5× its usual 11.7.
No cause named We have no fire or smoke records for these days, so we only say what the measurements show.
Cities reached 14 in 1 country
Days 2 29 to 30 August 2023
Worst day 29 August 12 cities counted
Furthest above usual 7.2× Aberdeen
Day by day
Play 29 August 12 cities at twice their usual or more
Omaha Bellevue Lincoln Ankeny Saint Paul Des Moines Rochester Waterloo Eau Claire Superior Duluth Iowa City Minneapolis Shakopee Burnsville Grand Island Blaine Apple Valley Saint Michael Brookings Saint Cloud Watertown Sioux Falls Bismarck West Fargo Aberdeen 26 Aug 27 28 29 30 31 1 Sep 2 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
Bismarck Bismarck, 26 August: 17.1 µg/m³, 1.5× usual Bismarck, 27 August: 10.8 µg/m³, 0.9× usual Bismarck, 28 August: 24.8 µg/m³, 2.1× usual Bismarck, 29 August: 64.5 µg/m³, 5.5× usual Bismarck, 30 August: 57.3 µg/m³, 4.9× usual Bismarck, 31 August: 20.6 µg/m³, 1.8× usual Bismarck, 1 September: 21.4 µg/m³, 1.8× usual Bismarck, 2 September: 20.5 µg/m³, 1.8× usual West Fargo West Fargo, 26 August: 7.5 µg/m³, 1.1× usual West Fargo, 27 August: 7.2 µg/m³, 1.0× usual West Fargo, 28 August: 15.3 µg/m³, 2.2× usual West Fargo, 29 August: 41.6 µg/m³, 5.9× usual West Fargo, 30 August: 34.9 µg/m³, 4.9× usual West Fargo, 31 August: 22.3 µg/m³, 3.1× usual West Fargo, 1 September: 18.7 µg/m³, 2.6× usual West Fargo, 2 September: 16.6 µg/m³, 2.3× usual Aberdeen Aberdeen, 26 August: 5.7 µg/m³, 1.1× usual Aberdeen, 27 August: 6.2 µg/m³, 1.2× usual Aberdeen, 28 August: 13.0 µg/m³, 2.5× usual Aberdeen, 29 August: 37.9 µg/m³, 7.2× usual Aberdeen, 30 August: 26.9 µg/m³, 5.1× usual Aberdeen, 31 August: 20.6 µg/m³, 3.9× usual Aberdeen, 1 September: 11.3 µg/m³, 2.1× usual Aberdeen, 2 September: 11.1 µg/m³, 2.1× usual Saint Cloud Saint Cloud, 26 August: 7.2 µg/m³, 1.0× usual Saint Cloud, 27 August: 12.4 µg/m³, 1.7× usual Saint Cloud, 28 August: 12.5 µg/m³, 1.7× usual Saint Cloud, 29 August: 34.7 µg/m³, 4.8× usual Saint Cloud, 30 August: 14.6 µg/m³, 2.0× usual Saint Cloud, 31 August: 14.6 µg/m³, 2.0× usual Saint Cloud, 1 September: 10.8 µg/m³, 1.5× usual Saint Cloud, 2 September: 13.8 µg/m³, 1.9× usual Watertown Watertown, 26 August: 6.2 µg/m³, 0.9× usual Watertown, 27 August: 7.2 µg/m³, 1.1× usual Watertown, 28 August: 12.2 µg/m³, 1.8× usual Watertown, 29 August: 32.7 µg/m³, 5.0× usual Watertown, 30 August: 29.9 µg/m³, 4.5× usual Watertown, 31 August: 21.9 µg/m³, 3.3× usual Watertown, 1 September: 15.9 µg/m³, 2.4× usual Watertown, 2 September: 16.0 µg/m³, 2.4× usual Saint Michael Saint Michael, 26 August: 6.9 µg/m³, 0.9× usual Saint Michael, 27 August: 12.5 µg/m³, 1.7× usual Saint Michael, 28 August: 9.9 µg/m³, 1.4× usual Saint Michael, 29 August: 31.0 µg/m³, 4.2× usual Saint Michael, 30 August: 12.1 µg/m³, 1.7× usual Saint Michael, 31 August: 11.0 µg/m³, 1.5× usual Saint Michael, 1 September: 10.2 µg/m³, 1.4× usual Saint Michael, 2 September: 12.8 µg/m³, 1.8× usual Burnsville Burnsville, 26 August: 7.1 µg/m³, 0.9× usual Burnsville, 27 August: 11.7 µg/m³, 1.5× usual Burnsville, 28 August: 11.5 µg/m³, 1.5× usual Burnsville, 29 August: 30.8 µg/m³, 3.9× usual Burnsville, 30 August: 11.6 µg/m³, 1.5× usual Burnsville, 31 August: 10.0 µg/m³, 1.3× usual Burnsville, 1 September: 10.6 µg/m³, 1.3× usual Burnsville, 2 September: 13.3 µg/m³, 1.7× usual Shakopee Shakopee, 26 August: 6.7 µg/m³, 0.8× usual Shakopee, 27 August: 11.3 µg/m³, 1.4× usual Shakopee, 28 August: 11.2 µg/m³, 1.4× usual Shakopee, 29 August: 30.6 µg/m³, 3.8× usual Shakopee, 30 August: 12.9 µg/m³, 1.6× usual Shakopee, 31 August: 10.0 µg/m³, 1.3× usual Shakopee, 1 September: 10.6 µg/m³, 1.3× usual Shakopee, 2 September: 13.3 µg/m³, 1.7× usual Apple Valley Apple Valley, 26 August: 6.8 µg/m³, 1.0× usual Apple Valley, 27 August: 10.9 µg/m³, 1.5× usual Apple Valley, 28 August: 9.8 µg/m³, 1.4× usual Apple Valley, 29 August: 28.8 µg/m³, 4.1× usual Apple Valley, 30 August: 11.9 µg/m³, 1.7× usual Apple Valley, 31 August: 9.3 µg/m³, 1.3× usual Apple Valley, 1 September: 9.5 µg/m³, 1.3× usual Apple Valley, 2 September: 11.7 µg/m³, 1.6× usual Minneapolis Minneapolis, 26 August: 5.2 µg/m³, 0.6× usual Minneapolis, 27 August: 11.4 µg/m³, 1.4× usual Minneapolis, 28 August: 10.5 µg/m³, 1.3× usual Minneapolis, 29 August: 28.8 µg/m³, 3.6× usual Minneapolis, 30 August: 9.9 µg/m³, 1.2× usual Minneapolis, 31 August: 9.4 µg/m³, 1.2× usual Minneapolis, 1 September: 9.9 µg/m³, 1.2× usual Minneapolis, 2 September: 12.3 µg/m³, 1.5× usual Brookings Brookings, 26 August: 5.2 µg/m³, 0.8× usual Brookings, 27 August: 4.8 µg/m³, 0.8× usual Brookings, 28 August: 11.3 µg/m³, 1.8× usual Brookings, 29 August: 27.0 µg/m³, 4.3× usual Brookings, 30 August: 28.1 µg/m³, 4.5× usual Brookings, 31 August: 19.0 µg/m³, 3.0× usual Brookings, 1 September: 14.6 µg/m³, 2.3× usual Brookings, 2 September: 12.8 µg/m³, 2.0× usual Blaine Blaine, 26 August: 5.2 µg/m³, 0.8× usual Blaine, 27 August: 11.5 µg/m³, 1.9× usual Blaine, 28 August: 9.5 µg/m³, 1.5× usual Blaine, 29 August: 25.7 µg/m³, 4.1× usual Blaine, 30 August: 8.9 µg/m³, 1.4× usual Blaine, 31 August: 8.6 µg/m³, 1.4× usual Blaine, 1 September: 9.6 µg/m³, 1.5× usual Blaine, 2 September: 11.6 µg/m³, 1.9× usual Sioux Falls Sioux Falls, 26 August: 3.8 µg/m³, 0.6× usual Sioux Falls, 27 August: 2.7 µg/m³, 0.5× usual Sioux Falls, 28 August: 5.6 µg/m³, 0.9× usual Sioux Falls, 29 August: 21.8 µg/m³, 3.6× usual Sioux Falls, 30 August: 30.8 µg/m³, 5.1× usual Sioux Falls, 31 August: 15.2 µg/m³, 2.5× usual Sioux Falls, 1 September: 8.0 µg/m³, 1.3× usual Sioux Falls, 2 September: 7.3 µg/m³, 1.2× usual Grand Island Grand Island, 26 August: 8.8 µg/m³, 1.3× usual Grand Island, 27 August: 7.4 µg/m³, 1.1× usual Grand Island, 28 August: 7.0 µg/m³, 1.0× usual Grand Island, 29 August: 13.0 µg/m³, 1.9× usual Grand Island, 30 August: 26.5 µg/m³, 4.0× usual Grand Island, 31 August: 14.1 µg/m³, 2.1× usual Grand Island, 1 September: 14.2 µg/m³, 2.1× usual Grand Island, 2 September: 11.9 µg/m³, 1.8× usual 26 Aug 27 28 29 30 31 1 Sep 2 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. Good 0–50
Moderate 51–100
Sensitive groups 101–150
Unhealthy 151–200
Very unhealthy 201–300
Hazardous 301+
Every city it reached
City Days Highest Usual Above usual
Aberdeen South Dakota, United States 2 29 August 5.3 7.2× West Fargo North Dakota, United States 2 29 August 7.1 5.9× Bismarck North Dakota, United States 2 29 August 11.7 5.5× Sioux Falls South Dakota, United States 1 30 August 6.0 5.1× Watertown South Dakota, United States 2 29 August 6.6 5.0× Saint Cloud Minnesota, United States 1 29 August 7.2 4.8× Brookings South Dakota, United States 2 30 August 6.3 4.5× Saint Michael Minnesota, United States 1 29 August 7.3 4.2× Blaine Minnesota, United States 1 29 August 6.2 4.1× Apple Valley Minnesota, United States 1 29 August 7.1 4.1× Grand Island Nebraska, United States 1 30 August 6.7 4.0× Burnsville Minnesota, United States 1 29 August 7.9 3.9× Shakopee Minnesota, United States 1 29 August 8.0 3.8× Minneapolis Minnesota, United States 1 29 August 8.1 3.6×
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 27 of 41 episodes in the United States since our records began, by cities reached.
North-eastern United States and Canada, June and July 2023 279 North-eastern United States and Canada, May and June 2023 260 North-eastern United States and Canada, July 2023 241 North-eastern United States and Canada, June 2023 161 North-western United States and Canada, August 2023 110 North-eastern United States and Canada, July 2023 75 Western United States, September 2023 61 South-eastern United States, October 2023 47 North-eastern United States, July 2023 46 North-western United States and Canada, May 2023 42 Western United States, December 2023 32 Northern United States, January 2023 32 Minnesota and South Dakota, United States, August 2023 14 Bars: cities reached; colour: the level of the episode's highest daily reading. All 41 .
Use this page SmogRank, Minnesota and South Dakota, United States, August 2023: 14 cities with PM2.5 at twice their usual or more, 29 to 30 August 2023, smogrank.com/episodes/2023-08-minnesota-and-south-dakota-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.
