Canada wildfire smoke is drifting from the Midwest to the East Coast

Dense smoke from wildfires burning in Canada continued to migrate eastward Wednesday, swinging around a low-pressure area now moving offshore on the East Coast. In its wake, a channel of thick surface smoke draped across the Great Lakes and Ohio Valley, and increasingly over the Mid-Atlantic.

Detroit, Chicago, Minneapolis and Washington were among the cities with the worst air quality in the world Wednesday, according to IQAir. Unhealthy Code Red and Purple conditions stretched from eastern Iowa across Chicago and the lower Great Lakes region, then toward the Appalachian Mountains, according to AirNow.