Next 24 hours

US AQI

45Now
41
37
379 PM
37
37
3712 AM
37
37
383 AM
39
39
396 AM
38
37
379 AM
37
37
4012 PM
43
45
463 PM
46
47

Air quality outlook

Worst hour each day

Today49Good
Thu 847Good
Fri 947Good
Sat 1092Moderate
Sun 1149Good

From our air-quality forecast models (GEOS-CF / GEFS aerosols). AQI uses the US EPA scale.

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About Chicago weather

Chicago is in Cook County, Illinois, United States at 41.85°, -87.65°. Right now it’s 69° and partly cloudy; today’s high is 76° with a 0% chance of rain.

Illinois has a humid continental climate with distinct seasons marked by cold, snowy winters and hot, humid summers. The state's flat terrain allows weather systems to move across without obstruction, leading to rapid temperature changes. Chicago's position on Lake Michigan creates a unique lake-effect weather pattern that can moderate summer heat and intensify winter snowfall.