Wildfires in Canada cause record AQI in Detroit and Midwest

Hazardous smoke from hundreds of wildfires burning across Canada blanketed a vast region of North America on Thursday, July 16, 2026, triggering widespread air quality alerts and creating dangerous health conditions for millions of residents from the Midwest to the Northeast. Detroit recorded the worst air quality of any major city in the world, with an Air Quality Index reaching as high as 698, a level considered an emergency threat to public health.

The dense plumes, originating primarily from intense and uncontrolled fires in Ontario, Manitoba, Saskatchewan, and Quebec, turned skies a hazy orange and compounded public health risks as they coincided with a severe heat wave. Canadian authorities reported 858 active fires as of Thursday morning, with hundreds considered out of control. More than 100 fires are also burning in the United States, including at least 15 in northern Minnesota. A northerly wind pattern funneled the smoke south and east, placing Michigan directly in the path of the densest plume and spreading pollution across the Great Lakes and Northeast.

Air quality indices reached dangerous levels in numerous major cities. Chicago and Minneapolis also registered...