More than 830 wildfires were burning in Canada on Wednesday, and winds are directing heavy smoke into the upper Midwest and Northeast, creating dangerous air quality for millions.
More than a dozen wildfires in northern Minnesota near the border are growing with little or no containment and forcing mandatory evacuations, and some of the largest blazes are burning in west-central Ontario through thick forests that are releasing an incredible amount of smoke.
Very heavy smoke is over Duluth, Minnesota, and Marquette, Michigan, on Wednesday morning, and extreme smoke is over northern Wisconsin.
Air quality alerts are in place from Minnesota to New York City, including the entire states of Wisconsin and Michigan.
Some heavy smoke will move over New York State and New England by mid-morning, potentially reaching New York City to Boston by 2 p.m. ET; by sunset on Wednesday, very heavy smoke may reach from Buffalo to New York City and Philadelphia, streaming through Green Bay, Milwaukee, Grand Rapids, Detroit and Toronto.
Minnesota officials issued an air quality alert from Tuesday through Friday for areas including the Twin Cities metro area.
Rain on Friday over the upper Midwest and on Saturday for the Northeast should help disperse smoke.
Conditions could be Mars-like and smelling like a campfire and some of the worst air quality in the world on Thursday from Duluth to Green Bay and Marquette through much of northern Michigan.
Cleveland, Columbus, Baltimore and D.C. will likely see heavy smoke on Thursday.
Conditions in New York City are not expected to be as intense as they were in June 2023.