Canadian wildfire smoke to affect air quality, visibility in parts of US: What to know

(WGN/NEXSTAR) – Smoke from wildfires burning in Canada is expected to cast a haze over the skies — and diminish air quality — in parts of the U.S. over the coming days.

There are roughly 160 wildfires currently burning across Canada, the majority of which are out of control, according to the Canadian Interagency Forest Fire Center (CIFFC). The high-intensity fires, scattered throughout the country from the Northwest Territories through Ontario, have prompted the evacuation of thousands of residents.

The CIFFC also said the country’s National Preparedness Level has been raised to a 5 — its highest level — meaning wide mobilization of firefighters and requests for help from outside of Canada.

The wildfires are also sending smoke down into the U.S., affecting the air quality in much of the country by the end of the weekend.

A forecast from the National Weather Service says visible surface smoke will begin creeping into the Midwest and Plains regions Friday before expanding to the East Coast and as far down as Texas and Georgia by Sunday. How bad it gets, however, depends on location.

A reduction in air quality, as well as reduced visibility, is expected in the Chicagoland area through the weekend, Nexstar’s WGN reported. Air quality alerts and advisories had also been issued for parts of Michigan, Minnesota, and state-wide in Wisconsin.

“Over the next few days, hazy skies and elevated levels of fine particle pollution (PM2.5) will likely result in poor air quality conditions in much of the state,” the Wisconsin DNR predicted Thursday.

Forecasts for other parts of the country can be found at AirNow.gov, a resource spearheaded by the Environmental Protection Agency.

Canada’s Manitoba province, meanwhile, has declared a state of emergency over the wildfires, which have put more than 17,000 residents under evacuation orders. The military has also been called in to help fight the blazes, which have cropped up faster in 2025 than in previous years.

Researchers say the increase in wildfire activity is driven by climate change. Such fires have also contributed to about 15,000 deaths from exposure to smoke particulates in the U.S. between 2006 and 2020.

These particles can lodge deep into lungs and trigger coughing and itchy eyes with short-term exposure. But longer term they can make existing health problems worse and lead to a range of chronic and deadly health issues. Children, pregnant people, the elderly and outdoor workers are among the most vulnerable.

“We’re seeing a lot more of these wildfire smoke events,” said Nicholas Nassikas, a physician and professor of medicine at Harvard Medical School who co-authored a recent study on the subject. “What does it really mean in a changing environment for things like mortality, which is kind of the worst possible health outcome?”

 The Associated Press contributed to this report.