Wildfire smoke from large fires burning in Ontario, Canada and Minnesota has blanketed the Great Lakes region in some of the worst air quality conditions the Midwest has seen in years, with northeast Minnesota reaching the Hazardous (Maroon) AQI category — the top of the air quality scale — and the smoke plume pushing south through Michigan, Wisconsin and beyond through Thursday.
Northeast Minnesota: Hazardous AQI Through Friday
The Minnesota Pollution Control Agency issued its most severe air quality alert for northeast Minnesota through 11 AM CDT Friday, forecasting AQI in the Maroon or Hazardous category across the Arrowhead region. Communities affected include International Falls, Ely, Hibbing, Two Harbors, Silver Bay, Grand Marais, Walker, Grand Rapids, Brainerd, Duluth, Aitkin and Pine City.
“The onset of smoke will be rapid,” the MPCA warned, adding that hot temperatures combined with the air pollution will exacerbate health impacts. At the Hazardous level, everyone — not just sensitive groups — is more likely to be affected. The agency instructed sensitive individuals to remain indoors with activity levels low, and the general public to avoid all outdoor physical activities.
Michigan: Unhealthy to Hazardous Across the Upper Peninsula and Northern Lower Michigan
The Michigan EGLE (Department of Environment, Great Lakes, and Energy) issued Air Quality Alerts through Thursday for the entire Upper Peninsula and all of northern lower Michigan. Pollutants across the UP are expected to range from Unhealthy for Sensitive Groups in the south to Unhealthy in the north, with hourly concentrations at times reaching Very Unhealthy to Hazardous. Upper Peninsula communities under alert include the Keweenaw, Ontonagon, Marquette, Houghton, Baraga, Alger and Dickinson areas.
Northern lower Michigan — including Traverse City, Petoskey, Gaylord, Cheboygan, Alpena, Mackinac Island, Charlevoix and Manistee — faces Unhealthy conditions with hourly spikes to Very Unhealthy or Hazardous. Michigan residents should keep windows closed, run central air conditioning with MERV-13 or higher rated filters, and monitor conditions at Michigan.gov/MiAir.
Wisconsin: Statewide Smoke Through Thursday, Worst Near Lake Superior
The Wisconsin DNR issued Air Quality Advisories covering all 72 Wisconsin counties through noon Thursday, with the potential for extension. The smoke entered northwest Wisconsin between 8 PM and midnight Tuesday night and has been pushing south-southwest since, reaching the Eau Claire-Sheboygan line by noon Wednesday and tracking toward the La Crosse-Janesville line by midnight.
The heaviest impacts are in northwest Wisconsin along the Lake Superior shoreline — Superior, Washburn, Bayfield, Ashland and Hurley — where the DNR forecasts Hazardous (Maroon) NowCast AQI values possible. The DNR also flagged lake-enhanced smoke concentrations for communities near Lake Michigan. Central and eastern Wisconsin (Green Bay, Appleton, Wausau, Madison, Oshkosh, Sheboygan) face Orange to Purple AQI through Thursday.
Protecting Yourself During a Smoke Event
For Very Unhealthy or Hazardous AQI: sensitive groups should avoid all outdoor activity; everyone else should limit outdoor time and go indoors at the first sign of symptoms — wheezing, coughing, chest tightness, dizziness, or burning in the nose, throat and eyes. Keep windows closed, run air conditioning on recirculate with a high-quality filter, and avoid outdoor burning and wood-burning devices. Track real-time air quality at AirNow.gov and airquality.wi.gov.
