Smoke from wildfires burning in Ontario has caused air quality to reach “dangerous” levels across Canada, and the northeastern and midwestern United States. And it could get worse before conditions improve.<\/p>\n
Published Jul 15, 2026 11:50 AM EDT\t\t\t\t\t<\/p>\n
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Updated Jul 17, 2026 9:49 AM EDT\n\t\t<\/p>\n
\n\t\tSmoke from wildfires burning in Canada has enshrouded the sky, sparking air quality concerns in the Midwest and Northeast regions of the U.S. on July 15.\n\t<\/p>\n
\n\tMassive plumes of smoke are descending across parts of Canada and the United States, creating dangerous air quality and scenes reminiscent of the historic wildfire smoke outbreak from three summers ago.\n<\/p>\n
\n\t“In 2023, a major fire outbreak in Quebec caused days of unhealthy air quality in the northeastern U.S.,” AccuWeather Vice President of Forecast Operations Dan DePodwin said. “This event could cause similar levels of poor air quality in spots.”\n<\/p>\n
\n\tAir quality alerts have been issued for millions of people, including across all of Delaware, Maryland, Michigan, New Jersey, Ohio, Pennsylvania, and Wisconsin.\n<\/p>\n
\n\tOver 800 wildfires<\/a> are currently burning across Canada, including dozens that are out of control across western Ontario, the source of most of the smoke. “Many of these fires may have been started by lightning,” AccuWeather Senior Meteorologist Brett Anderson said.\n<\/p>\n \n\tDangerous air quality (purple) was widespread across the Great Lakes on Friday, July 17, 2026, due to wildfire smoke. (AccuWeather)\n<\/p>\n \n\tConditions started to deteriorate across the region on Wednesday, becoming more widespread on Thursday. People across the mid-Atlantic, including New York City, could smell smoke when stepping outside on Thursday afternoon.\n<\/p>\n \n\tOn Friday morning, “dangerous” air quality was commonplace from northern Minnesota through Delaware. Chicago<\/a> was one of the worst cities for air quality with an AQI of 342. The AQI was also over the “dangerous” threshold of 250 in Washington, D.C.<\/a>, Pittsburgh<\/a>, Cleveland<\/a> and Detroit<\/a>.\n<\/p>\n