Chicago Has Worst Air Quality Among World's Major Cities On Thursday

ILLINOIS — Many in the Chicago area have noticed hazy, smoky skies on Thursday as an air quality alert due to unhealthy levels of wildfire smoke was in effect.

The Illinois Environmental Protection Agency has issued a "red forecast air pollution action day" for Thursday for the areas of: Rockford, Lake County, Chicago, north and west suburbs, south and west suburbs, Will County and Aurora-Elgin.

"Everyone should reduce prolonged activities or heavy exertion outdoors. Active children, older adults, and people with pulmonary or respiratory disease such as asthma should avoid prolonged activities or heavy exertion outdoors," the National Weather Service advised.

The air quality alert is due to particulates from wildfire smoke.

According to IQ Air's major city air quality ranking, Chicago had the worst air quality in the world as of 1 p.m. Thursday. The air quality index was 183, which falls in the "unhealthy" level.

At this level, IQ Air advises avoiding outdoor exercise, close your windows to avoid dirty outdoor air, wear a mask outdoors and run an air purifier.

The Canadian wildfire smoke is also affecting the air quality in other U.S. cities. As of 1 p.m. Thursday, Minneapolis was ranked no. 3 for the worst air quality, and Detroit was ranked no. 6.

With cooler temperatures after a heat wave ended in the Chicago area, here's a look at the forecast:

Thursday night: Isolated sprinkles after 10pm. Patchy smoke before 1am. Partly cloudy, with a low around 65. North northeast wind 5 to 15 mph, with gusts as high as 20 mph.

Friday: Isolated sprinkles before 1pm. Mostly sunny, with a high near 77. Northeast wind 5 to 10 mph, with gusts as high as 15 mph.

Friday night: Mostly clear, with a low around 61. North northeast wind 5 to 10 mph becoming light north in the evening.

Saturday: Mostly sunny, with a high near 79. North wind 5 to 10 mph becoming east northeast in the afternoon.

Saturday night: Partly cloudy, with a low around 62.

Sunday: Mostly sunny, with a high near 81.

Sunday night: Partly cloudy, with a low around 65.