More than 800 wildfires are burning across Canada, with smoke triggering air quality alerts in multiple US states. The US Air Quality Index has classified conditions as "hazardous" in parts of Michigan, Minnesota, and the Upper Midwest.
Wildfire smoke spreads across US
Air quality alerts now extend from the Upper Midwest to the Great Lakes region and the Northeast, according to a Thursday update from the National Oceanic and Atmospheric Administration (NOAA). The Canadian Interagency Forest Fire Centre reports 857 active fires, including 23 new blazes on Thursday.
The majority of these wildfires remain out of control, per the Canadian Wildland Fire Information System. A cluster of fires in western Ontario is sending thick smoke into Thunder Bay and Toronto, with lighter concentrations drifting over the Great Lakes and New York, causing hazy skies and red-tinted sunrises and sunsets.
Forecast and impact on US cities
Thunderstorms are expected in Ontario over the coming days, but officials warn the rain may not significantly reduce the fires. Northwesterly winds will continue pushing smoke into northern US states through the weekend, raising concerns about air quality during Sunday’s World Cup final in New Jersey. A wind shift by Monday may redirect smoke toward Quebec, improving conditions further south.
Detroit currently has the world’s worst air quality, according to Swiss tracker IQAir, followed by Minneapolis and Toronto. On Wednesday, a freight train in Ontario was surrounded by flames, prompting an emergency rescue. Canadian National Rail confirmed all trapped workers near Armstrong were safely evacuated, and operations in the region remain suspended.
