In the USA there is an air quality warning about smoke development from Canadian wildfires

Smoke from wildfires in western Canada is returning to the United States, and air quality warnings will be issued for upper Midwest communities beginning over the weekend.

Hundreds of wildfires continue to burn north of the U.S.-Canada border, but weather system positions over the next few days will help usher in a new plume of smoke that could hit Montana, the Dakotas and Minnesota and reach as far south as Nebraska and Iowa .

The Minnesota Pollution Control Agency said it expects the air quality index to reach at least 100, making the air unhealthy on Friday and Saturday.

The AQI ranges from 0 to 500, with lower values ​​indicating cleaner air and any value above 300 being dangerous.

The agency warns people with asthma and heart disease, both young and old, that they could experience hypersensitivity during the recent bout of smoking.

Forecast models show the smoke will thicken over the Plains and upper Midwest through Friday before drifting east and potentially impacting air quality around the Great Lakes on Saturday and Sunday.

Smoke from wildfires engulfed major cities along the Interstate-95 corridor in June, making for hazy skies and limited visibility.

Air quality levels reached dangerous levels in Philadelphia, New York and other communities downwind of the Quebec fires.

Large outdoor events, including several Major League Baseball games, have been postponed due to the risk, health officials said, from prolonged exposure.

An unusually dry start to the year and a significant heatwave have fueled more than 3,400 fires across Canada, according to a government dashboard.

Across the country, wildfires have destroyed nearly 22 million acres of land, about the size of Indiana.

Firefighters from around a dozen countries are working to contain the blazes in the country’s worst fire season on record.

An increase in thunderstorms has provided drought relief in some provinces, but the Canadian Interagency Forest Fire Center said lightning has started hundreds of new fires.

The FOX Forecast Center said a heavy layer of smoke is not expected in the Northeast for the next few days due to prevailing weather conditions.