Air quality alert this weekend for all of Minnesota and Wisconsin

Another batch of Canadian wildfire smoke will drift across Minnesota this weekend.

Air quality Friday afternoon was in the very unhealthy (purple) range across the Red River Valley. Thicker smoke is spreading southeast across northern and central Minnesota behind the cold front.

It looks like we’ll see two waves of smoke dive across Minnesota this weekend.

The National Oceanic and Atmospheric Administration’s High-Resolution Rapid Refresh model smoke output shows the two waves moving across our region. The forecast model loop below runs between 4 p.m. Friday and 1 p.m. Sunday.

Here are the details on the air quality alert for Minnesota this weekend:

Air quality alert issued due to wildfire smoke until Monday, July 14, for all of Minnesota

Air quality is expected to reach the purple AQI category in northern Minnesota, which is very unhealthy for everyone.

The Minnesota Pollution Control Agency (MPCA) has issued an air quality alert for all of Minnesota. The alert runs until 9 a.m. on Monday, July 14. 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.

Heavy ground-level smoke from wildfires in central Canada moved into northwest Minnesota early Friday morning behind a cold front. This first band of smoke is currently impacting northern Minnesota as it moves east during the day Friday. Air quality will worsen across northeast Minnesota Friday evening as smoke arrives over the region. A second round of smoke will move into northwest Minnesota late Friday evening. This smoke will be more widespread as it moves southeast overnight, and by Saturday afternoon the entire state may be impacted. The heaviest smoke on Saturday will be across the northern half of the state. Air quality will begin to improve across western Minnesota Sunday morning as cleaner air moves in from the west. By Sunday evening, the smoke should be gone from most of the state. Another round of smoke is possible across far northern Minnesota Sunday night.

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

Saturday will produce the worst air quality this weekend, especially in northern Minnesota.

Air quality should begin to improve from west to east across Minnesota Sunday afternoon.

Here’s the detailed forecast discussion from the Minnesota Pollution Control Agency:

Updated Fri, Jul 11, 2025

KEY MESSAGES: AQA in effect statewide due to wildfire smoke until Monday morning. Heavy smoke impacts northern MN Friday. A second wave of widespread heavy smoke to impact the entire the state Saturday. Smoke will clear through the day Sunday, but additional smoke may arrive in northern MN Sunday evening.

DETAILED DISCUSSION: A statewide Air Quality Alert is in effect until 9 AM Monday. Very heavy wildfire smoke is impacting northern MN as it moves east behind a cold front on Friday. This band of smoke will reach northeast MN by the evening. Air quality will reach the Purple (Very Unhealthy) category for several hours for northwest MN Friday. Air quality may reach the Purple (Very Unhealthy) category for several hours across north central and northeast MN later in the day Friday. A second wave of heavy smoke is expected to arrive into the state Friday evening and by Saturday afternoon may cover the entire state. The worst air quality Saturday will be across northern MN, where Purple AQI is possible for at least several hours. Air quality may reach the Red (Unhealthy) category for central MN and the Orange (Unhealthy for Sensitive Groups) category for far southern MN. Cleaner air will move into the state from the west on Sunday and air quality should improve. Western MN will see air quality improve first and by the end of the day Sunday the smoke should have exited most of the state. Another round of smoke may move into northern MN Sunday evening. Therefore, we opted to keep the alert in effect until Monday morning.

Highs this weekend will run mostly in the 70s Saturday but will reach the 80s across much of Minnesota Sunday.