Illinois Weather Records
Weather averages and records for the U.S. state of Illinois based on data made available by the NOAA.
Illinois Statewide Averages
Average temperatures and precipitation over the entire territory of the state, from 1991–2020.
Hottest Temperature All-Time
The highest recorded temperature in Illinois history was 117 °F, which was reached in East Saint Louis on July 14, 1954.
Coldest Temperature All-Time
The lowest temperature in Illinois history was -38 °F, which was recorded in Mt. Caroll on Jan 31, 2019.
Yearly weather averages for various places in Illinois, from 1991–2020.