Cook County has 119 places on myweatherrock (97 villages, 21 cities, 1 towns), each with its own live forecast, hourly timeline, ten day outlook and radar. The hottest day in the station records is 107°F at Chicago Midway Ap 3Sw on June 1, 1934. The coldest night is -28°F at Barrington 3Sw on January 31, 2019. The wettest day brought 10 inches of rain at Little Red School House on July 18, 1996. The biggest single-day snow measured 19.02 inches at Park Forest Water on February 2, 2011. Those are station measurements from NOAA's daily records, 1897 to 2026, not official state records. By area the largest place is Chicago, about 225 square miles.
About Cook County weather
The map on the Now tab shows every Cook County town's current temperature from our own server, one dot per town. Tap any dot, or type a town above, for that town's full forecast.
What the weather is usually like
Across the 119 Cook County towns with station normals, the warmest month is July, when the day usually reaches 84°F, and the coldest is January, when the night usually falls to 18°F. May is the wettest, with rain on about 12 days. July afternoons run from about 82°F in Barrington to 85°F in Alsip. January nights run from about 14°F in Barrington to 21°F in Chicago.
Means of the 1991 to 2020 station normals serving these towns, as published by NOAA; each town's page carries its own.
Where these numbers come from
Current conditions and forecast: NOAA forecast grids decoded on our own server, corrected against the nearest reporting station and our own radar. Open-Meteo is consulted only as a fallback when our server is silent.
Records: computed by myweatherrock from NOAA GHCN-Daily station records at the stations serving these towns. Measurements, not estimates.
Warnings and alerts: the National Weather Service, passed through unchanged.
Cook County weather records
Hottest day
107°F
Chicago Midway Ap 3Sw, June 1, 1934
Coldest night
-28°F
Barrington 3Sw, January 31, 2019
Wettest day
10 in
Little Red School House, July 18, 1996
Biggest snow
19.02 in
Park Forest Water, February 2, 2011
Measured at the NOAA stations serving these towns, daily records 1897 to 2026. Station extremes, not official state records.
Common questions about Cook County weather
What is the hottest temperature recorded at a Cook County station?
107°F at Chicago Midway Ap 3Sw on June 1, 1934, in the NOAA daily station records myweatherrock holds (1897 to 2026).
What is the coldest temperature recorded at a Cook County station?
-28°F at Barrington 3Sw on January 31, 2019.
What is the most rain a Cook County station has measured in one day?
10 inches at Little Red School House on July 18, 1996.
What is the biggest one-day snowfall at a Cook County station?
19.02 inches at Park Forest Water on February 2, 2011.
How many Cook County towns have a weather page here?
119: 97 villages, 21 cities, 1 towns. Each page carries current conditions, the hourly timeline, the ten day outlook, radar, and where a station sits close enough, measured records.
Where does the Cook County forecast come from?
NOAA forecast grids (the National Weather Service digital forecast, the National Blend of Models, HRRR and GFS) decoded on our own server, corrected against the nearest reporting station and our own radar. Open-Meteo is consulted only as a fallback when our server is silent.
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