The Climate of Illinois describes the weather conditions, and extremes, noted within the state of Illinois, United States, over time. Because of its nearly 400-mile (640 km) length and mid-continental location, Illinois has a widely varying climate.

These maps describe the climate of Illinois using the official 1981-2010 normals from the National Climatic Data Center. Available maps include precipitation, temperature, snowfall, heating degree days, and cooling degree days, as well as number of days above or below selected thresholds of precipitation, temperature, and snowfall.

The Illinois State Climatologist provides maps of current climate conditions in Illinois including precipitation, mean temperature, maximum temperature, minimum temperature, and snowfall for selected time periods. These are typically updated around 11 am each day.

See the latest Illinois Doppler radar weather map including areas of rain, snow and ice. Our interactive map allows you to see the local & national weather.

The Illinois normals available on NCEI’s website and shown in the maps below based on data from 1991 through 2020. Available maps include precipitation, temperature, snowfall, heating degree days, and cooling degree days, as well as number of days above or below selected thresholds of precipitation, temperature, and snowfall.

Here are extensive climate statistics for individual sites in Illinois, including monthly normals and extremes. Stations were chosen based on length of record and completeness of data. Normal monthly temperature and precipitation data for all sites can be downloaded (Excel).

Illinois was both warmer and wetter than the 1991–2020 normal in 2024. The statewide average annual temperature was 55.5 degrees, 2.9 degrees above normal and 2nd warmest on record statewide ...

Climate and Average Weather Year Round in Illinois United States. We show the climate in Illinois by comparing the average weather in 3 representative places: Chicago, Springfield, and Carbondale. You can add or remove cities to customize …

Illinois Climate Network: Weather Data Station Data. Stations: Belleville Big Bend Bondville Brownstown Carbondale Champaign DeKalb Dixon Springs Fairfield Freeport Monmouth Olney Peoria ... Inversion Map: Illinois State Water Survey. 2204 Griffith Dr., MC-674 Champaign, IL 61820-7463 217-244-5459

Maps of current precipitation, mean temperature, maximum temperature, minimum temperature, and snowfall in Illinois. These maps typically update by 11 am each day. Additional maps for the Midwest are available from the Applied Climate Information System .