Thousands of Americans told to keep windows shut

An air quality alert was in effect for northwest and north-central Minnesota on Friday, with officials warning that wildfire smoke could prompt unhealthy levels of air pollution.

Why It Matters

Experts caution that unhealthy air quality heightens health risks for vulnerable populations, such as older adults, young children, and those with respiratory illnesses.

Six members of Congress have written Canada’s embassy to complain that smoke from Canadian wildfires is drifting south and making it difficult for Americans to enjoy summer.

“We write to you today on behalf of our constituents who have had to deal with suffocating Canadian wildfire smoke filling the air to begin the summer,” they told Ambassador Kirsten Hillman.

What To Know

According to the alert, published by the National Weather Service (NWS), thick smoke at ground level from wildfires in central Canada was expected to drift into northwest Minnesota early Friday morning.

The first wave of smoke would swiftly pass through northern Minnesota during the day and reach the northeast region by Friday evening, it forecast.

A second, broader smoke plume was expected to arrive in northwest Minnesota later Friday evening. This next wave was likely to cover a larger area and could affect much of the northern half of the state on Saturday, the alert said.

Officials said the air quality alert might need to be extended to account for this second event. Cleaner air was forecast to arrive from the west on Sunday, leading to improved air quality by Sunday afternoon.

“Reduce or eliminate activities that contribute to air pollution, such as outdoor burning, and use of residential wood burning devices,” the alert advised. “Reduce vehicle trips and vehicle idling as much as possible. Keep windows closed overnight to prevent smoke from getting indoors.”

Air pollution is measured using the Air Quality Index (AQI), which runs on a scale from 0 to 300 and above.

• 0–50 (Green): Good. Air quality is satisfactory.
• 51–100 (Yellow): Moderate. Air quality is acceptable, with potential concerns for sensitive individuals.
• 101–150 (Orange): Unhealthy for Sensitive Groups. Air quality may affect people with heart or lung disease, older adults, children and pregnant individuals.
• 151–200 (Red): Unhealthy. Everyone may begin to experience health effects, and sensitive groups may see more serious effects.
• 201–300 (Purple): Very Unhealthy. The risk of health effects is increased for everyone.
• 301 and above (Maroon): Hazardous. The air quality requires a health warning of emergency conditions, and everyone is more likely to be affected.

What People Are Saying

The Minnesota Pollution Control Agency said on X, Thursday: “An air quality alert has been issued due to wildfire smoke for Friday, July 11, for northwest and north central Minnesota. Air quality is expected to reach the purple AQI category in northwest Minnesota, which is very unhealthy for everyone.”

Jonathan Grigg, professor of pediatric respiratory and environmental medicine at Queen Mary, University of London, previously told Newsweek that there are “very clear links” between inhaling particles and earlier death from both respiratory and cardiovascular diseases.

He added: “There are vulnerable groups and classically they are children because they’ve got an extra issue to do with their lungs developing, whereas our lungs are not developing as adults.”

Tom Emmer, serving as Majority Whip in the House of Representatives an five fellow Republican lawmakers wrote in a letter, published Monday, to Canada’s embassy: “We would like to know how your government plans on mitigating wildfire and the smoke that makes its way south.”

They added: “Our constituents have been limited in their ability to go outside and safely breathe due to the dangerous air quality the wildfire smoke has created.

What Happens Next

At the time of writing, the air quality alert for Minnesota was in place until 6 p.m. CDT on Friday.