Illinois Weather Averages
Select a link for the average weather, by month or year, in cities throughout Illinois. The links take you to data for normal temperatures, precipitation, snowfall, sunshine and humidity.
Farther down the page you'll find links to in-depth weather information for Chicago, Rockford and other places in the state.
In-depth Weather Information
- Chicago Weather Averages
- Chicago Temperatures by Month
- Chicago Snowfall Totals and Snow Accumulation Averages
- Hot, Humid Weather in Illinois
Climate information about temperature, precipitation, snow, sun, humidity, wind and storms in Chicago.
Detailed temperature information for Chicago, Illinois with statistics on average monthly highs and lows plus number of days with hot or cold weather.
When, how much and how often Chicago has snow — with monthly and yearly averages on total days and inches of snowfall, snow accumulation, heavy snowstorms and first snowfall.
How often heat combines with humidity at cities in Illinois to create uncomfortably muggy weather.