Heavy smoke from hundreds of wildfires burning primarily in Canada, as well as northern Minnesota, has blanketed a large portion of the United States, stretching from the Great Lakes region to parts of the East Coast. This has led to significant health warnings and reduced visibility across the affected areas.

Detroit recorded the worst air quality of any city worldwide on Thursday, July 16th, 2026, with a pollutant index of 600—double the level considered "hazardous" by the US Environmental Protection Agency, according to monitoring company IQAir.

Ten states reported locations with "unhealthy" air quality readings, spanning from Minnesota down to Maryland. Officials have urged residents to stay indoors when possible, wear masks, and avoid exposure to the acrid air.

New York City Mayor Zohran Mamdani stated on Thursday, July 16th, 2026, "Today is expected to be the worst day of this event," and advised that "every New Yorker should take precautions." Health concerns are widespread, with reports of scratchy throats and unpleasant odors in the air. One resident noted, "It stinks. It's not a good sign when you wake up in the morning and you can smell the air."

Emily Fischer, an atmospheric chemist and professor at Colorado State University, described the situation as "basically a river of smoke pouring into the Midwest right now."

Residents across the affected states are cautioned that at these "unhealthy" levels, everyone—not just those with pre-existing conditions—may experience adverse health effects.

Sources