Worst air quality in the world for parts of Minnesota this week

The smoky summer of 2025 is back.

The air quality index reading of 221 in Grand Portage (map below) along Minnesota North Shore is higher than the 216 reading for Kinshasa in the Democratic Republic of the Congo Wednesday.

The Twin Cities are listed as the third most polluted major city in the world Thursday morning, according to iqair.com. (map above)

A widespread plume of Canadian wildfire smoke has sagged southward into Minnesota once again. This time the plume is thicker and producing unhealthy air quality for parts of Minnesota and will last most of this week.

This latest air quality alert covers all of Minnesota until 5 p.m. Saturday. This alert ties the longest air quality alert on record (Greenwood Fire 2021 in St. Louis County) according to meteorologist Matt Taraldsen with the MPCA.

Air quality is expected to reach the red AQI category in northern and central Minnesota, which is unhealthy for everyone. Air quality is expected to reach the orange AQI category in southern Minnesota, which is unhealthy for sensitive groups

The Minnesota Pollution Control Agency (MPCA) has issued an air quality alert for all of Minnesota. The alert takes effect 1 p.m. on Tuesday, July 29, and runs until 5 p.m. on Saturday, Aug. 2. The affected area includes the Twin Cities metro area, Brainerd, Alexandria, Albert Lea, Marshall, Worthington, Rochester, Hinckley, St. Cloud, Winona, Ortonville, Mankato, Bemidji, East Grand Forks, Moorhead, International Falls, Two Harbors, Hibbing, Ely, Duluth, Roseau, and the Tribal Nations of Upper Sioux, Mille Lacs, Prairie Island, Leech Lake, White Earth, Red Lake, Grand Portage, and Fond du Lac.

Northerly winds will continue transporting waves of heavy surface smoke from wildfires across Manitoba and Saskatchewan into Minnesota. Smoke will move south across all of Minnesota and linger through Saturday afternoon. The smoke will be reinforced by an area of high pressure that will create light winds and limit the dispersion of smoke. Therefore the air quality alert has been expanded to include all of Minnesota and extended until Saturday afternoon when the air quality is forecasted to improve. 

Fine particle levels are expected to reach the red air quality index (AQI) category, a level considered unhealthy for everyone, across west central, east central, central, south central, southeast, north central, northwest, southwest, and northeast Minnesota. This area includes the Twin Cities metro area, Brainerd, Alexandria, Hinckley, St. Cloud, Ortonville, Bemidji, East Grand Forks, Moorhead, International Falls, Two Harbors, Hibbing, Ely, Duluth, Roseau, and the Tribal Nations of Upper Sioux, Mille Lacs, Prairie Island, Leech Lake, White Earth, Red Lake, Grand Portage, and Fond du Lac. In the red area, sensitive groups should avoid prolonged or heavy exertion and limit time spent outdoors. Everyone should limit prolonged or heavy exertion and time spent outdoors. 

Fine particle levels are expected to reach the orange AQI category, a level considered unhealthy for sensitive groups, across southwest, southeast, and south central Minnesota. This area includes Albert Lea, Marshall, Worthington, Rochester, Winona, and Mankato. In the orange area, sensitive groups should limit prolonged or heavy exertion and time spent outdoors.

Tracking the smoke plume

NOAA’s HRRR smoke output shows how smoke of varying intensity will drift across Minnesota the next couple days. The forecast model loop below runs between 1 p.m. Wednesday and 7 a.m. Friday.

Southerly winds should help improve air quality from south to north starting Friday into Saturday. People should limit outdoor activity this week. It looks like the worst air quality will be through Thursday into Friday but may gradually improve for weekend events like the Great River Energy – Mesabi Trail Tour bike event Saturday.

Stay safe Minnesota.

Correction (July 31, 2025): An earlier version of this story misspelled Matt Taraldsen's name. The story has been updated.