More than 830 wildfires were burning on Wednesday in Canada, along with more than a dozen in northern Minnesota, near the border, growing with little or no containment and forcing mandatory evacuations.

Some of the largest wildfires are burning in west-central Ontario, and those fires are burning through thick forests, releasing an incredible amount of smoke. 

The wind is now directing that very heavy smoke into America, creating dangerous air quality for millions across the upper Midwest and Northeast on Wednesday and through the end of the week

Rain on Friday over the upper Midwest and on Saturday for the Northeast should help disperse smoke. 

Very heavy smoke is over Duluth, Minnesota, and Marquette, Michigan, on Wednesday morning, and extreme smoke is over northern Wisconsin.

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.

Conditions in New York City are not expected to be as intense as they were in June 2023.

Hazy skies are expected and air quality will likely become unhealthy.

Conditions could, however, be that bad — 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.

The smoke will be serious for millions and may reach a dangerous level for everyone — not just those with respiratory issues.

Air quality alerts are in place from Minnesota to New York City, including the entire states of Wisconsin and Michigan.