New air quality alert issued for northeast Minnesota for Tuesday and Wednesday

We’re breathing easier across most of Minnesota on this first Monday in August.

But we’re still living on the edge of a smoky smudge from Canadian wildfires to the north. A smudge of wildfire smoke to the east is clipping eastern Minnesota through Monday night. Air quality is unhealthy in southeast Minnesota including Rochester as of this post Monday afternoon.

Some smoke will clip the Twin Cities and eastern Minnesota Monday night into Tuesday morning. Tuesday and Wednesday smoke will focus in northeast Minnesota. NOAA’s HRRR near surface smoke output shows the smoky trends for northeast Minnesota.

Here’s the air quality alert detail from MPCA.

The Minnesota Pollution Control Agency (MPCA) has issued an air quality alert for northeast Minnesota. The alert takes effect 1 a.m. on Tuesday, Aug. 5, and runs until noon on Wednesday, Aug. 6. The affected area includes Two Harbors, Hibbing, Ely, Duluth, and the Tribal Nations of Grand Portage and Fond du Lac.

Areas of heavy surface smoke across Wisconsin and Michigan will rotate northwestward around a large area of high pressure. Northeastern Minnesota has the highest likelihood for an extended period of fine particle pollution in the orange AQI category, from early Tuesday morning into Wednesday. However, shorter periods of poor air quality are possible from southeastern Minnesota through north central Minnesota as well.

Fine particle levels are expected to reach the orange air quality index (AQI) category, a level considered unhealthy for sensitive groups, across northeast Minnesota. This area includes Two Harbors, Hibbing, Ely, Duluth, and the Tribal Nations of Grand Portage and Fond du Lac. In the orange area, sensitive groups should limit prolonged or heavy exertion and time spent outdoors.

What this alert means

Air moves long distances and carries pollutants. During air quality alerts due to wildfires, the air is mixed with harmful smoke. Wildfire smoke spreads or lingers depending on the size of the fires, the wind, and the weather.

The air quality index (AQI) is color-coded. Air quality alerts are issued when the AQI is forecast to reach an unhealthy level, which includes forecasts in the orange, red, purple, and maroon categories. For a full description of each air quality category, visit airnow.gov.

Here’s the forecast discussion detail from MPCA.

Updated Mon, Aug 4, 2025

KEY MESSAGES: 1.) Predominantly moderate levels of wildfire smoke remains across the state today.

2) An air quality alert has been issued for northeastern Minnesota from Tuesday into Wednesday.

3.) Another round of heavy surface smoke may impact Minnesota this weekend.

DETAILED DISCUSSION: Lingering smoke will remain over much of Minnesota today, with highest concentrations of fine particle pollution across eastern Minnesota. While there may be periods of Orange AQI-level concentrations, the forecast is for Yellow (moderate) AQI (which is based on a 24 hour average) statewide today. The likelihood for Orange AQI is highest on Tuesday into Wednesday across northeastern Minnesota, where heavy surface smoke will be most persistent. Increased humidity and cloud cover should keep ozone mainly Green (good) in the coming days. Looking further ahead, a cold front will move through the state this weekend, and heavy wildfire smoke may follow. Uncertainty exists due to the potential for substantial rain across some of the Canadian wildfires this week. Stay tuned for updates.

The air quality for the rest of Minnesota looks better through most of this week thanks to southerly winds.

Stay tuned.