Smoke from wildfires burning in Minnesota is expected to drift across the Great Lakes and into the Northeast, potentially causing dangerous air pollution in cities including Detroit, Milwaukee, Cleveland, Philadelphia and New York City. Currently, the smoke is relatively high up in the atmosphere. For context, in the color-coded Air Quality Index, red indicates “unhealthy,” while brown indicates “hazardous.”
Exactly how high the pollution levels will be and how long poor conditions may last is still somewhat uncertain. “Forecasting wildfire smoke is HARD, and model forecasts are often way off—either high or low,” wrote meteorologist Jeff Masters in a Bluesky post. “The models are in their infancy, and have to get the meteorology, fire behavior and atmospheric chemistry right.” Smoke could also make for hazy orange skies because the particles tend to scatter blue light but allow orange and red wavelengths to pass through.
The fires in Minnesota are unusual for this time of year, which is generally a wet period—fire season typically comes in spring or fall. But drought and exceptionally hot weather have left vegetation parched, which has made it primed to burn with any spark. Some such sparks came from lightning that passed through the Boundary Waters Canoe Area Wilderness and Superior National Forest last week. Steady winds have fanned the flames. Parts of those parks have been closed to visitors, and Minnesota’s governor Tim Walz has declared an emergency to allow the National Guard and other resources to assist with the fires.
The smoke from the fires could pose an air pollution problem periodically over the next 10 days, Masters notes. The best way to protect yourself from smoke is to limit time spent outdoors, wear an N95 mask when you do have to be outside and when air pollution is high, keep doors and windows closed and well sealed and run air purifiers inside.
Wildfire smoke from Minnesota and Canada will blanket Wisconsin this week, with air quality potentially reaching “very unhealthy” levels, particularly in the northern part of the state. The Wisconsin Department of Natural Resources issued an advisory July 14 saying the smoke is expected to enter northern Wisconsin on Tuesday evening and continue pushing south through July 16, at which point it could have covered the entire state. The U.S. Forest Service has closed the popular Boundary Waters Canoe Area and is evacuating campers. The smoke advisory is set to end in Wisconsin on July 16 at noon but “will likely be extended for at least some portion of the state” beyond that time, according to the DNR. It comes alongside another heat wave in which “feels like” temperatures could surpass 100 degrees across huge swaths of the state.
Across the state, levels could range from “unhealthy for sensitive groups” to “very unhealthy” this week. When the air quality index is at very unhealthy levels, everyone should limit outdoor physical activity and people with heart or lung issues should avoid all physical activity outdoors.
