Several blazes continued to rage across Canada on Saturday, sending smoke drifting over multiple U.S. states in the Midwest and prompting warnings about unhealthy air for at least the third consecutive day.

Air quality alerts were in effect in Iowa, Minnesota, Wisconsin, and Michigan, as well as eastern Nebraska and parts of Indiana and Illinois. Conditions were especially dire in Minneapolis, Minnesota, with the Switzerland-based air quality monitoring database IQAir reporting that the U.S. city had some of the worst air pollution in the world since Friday.

The Air Quality Index (AQI)—a system used to indicate pollution levels in the air—is expected to reach the red or “unhealthy” category across a large swath of Minnesota, likely persisting through Saturday. “We’ve sort of been dealing with this, day in and day out, where you walk outside and you can taste the smoke, you can smell it,” said Joe Strus, a meteorologist with the National Weather Service in the Minneapolis–Saint Paul area.

Forecasters warned that smoky skies would linger across the Midwest for much of Saturday, though conditions may start to improve before the smoke spreads farther south into Tennessee and Missouri. Poor air quality poses particular risks for people with lung and heart conditions, as well as for children, the elderly, and pregnant women.

This is not the first time Canadian wildfires have triggered air quality alerts in the U.S. and beyond. In 2023, a record-breaking early wildfire season sent smoke drifting across the Atlantic into northern Europe.

On Saturday, the Canadian Interagency Forest Fire Centre reported “out-of-control” blazes in the provinces of British Columbia, Alberta, Saskatchewan, Manitoba, and Ontario, as well as in Yukon and the Northwest Territories. The centre stated that 717 fires were active across the country.

Environment Canada also reported “extremely high” levels of air pollution in Saskatchewan, Manitoba, Ontario, and the Northwest Territories, according to a report by The Canadian Press news agency. Areas in British Columbia, Alberta, and Quebec were also under air-quality watch, though health risks there were reportedly lower. Environment Canada said reduced visibility and poor air quality would persist into Sunday. (CNN)