Chicago faces an air quality alert due to Canadian wildfire smoke and high ozone levels, with risks for sensitive groups.

As the city's surface warms, it heats the air above it, causing that air to rise. This rising motion can pull in smoke-laden air from the north, bringing it down to the surface.

CHICAGO (WLS) -- An air quality alert was issued for the greater Chicago area on Tuesday. The alert was issued by the EPA at about 11:56 a.m. It will be in effect until midnight. Lake, Porter, Newton ...

As Canadian wildfire smoke lingers in the skies, the Chicago area will soon be under an air quality alert, but the smoke ...

While an air quality alert continues for parts of the Midwest due to smoke from Canadian wildfires, northeastern Illinois was ...

Air quality alerts were in effect in Iowa, Minnesota, Wisconsin and Michigan, as well as eastern Nebraska and parts of ...

Smoke from Canadian wildfires continues to affect air quality across the Midwest, though Monday’s conditions were an ...

Health officials from Minnesota to Maine have issued alerts warning of poor air quality from wildfires burning in Canada.