Illinois Weather
Observed at Chicago (the largest city by population in Illinois, used as a state-wide proxy). For per-city forecasts, see the city grid below.
Climate at a glance
Illinois covers two distinct climate zones across 1,456 cities and towns. Predominantly humid subtropical (59% of cities), with warm-summer humid continental pockets (41%).
The state spans roughly 5.5° of latitude (37.0° N to 42.5° N), from Cairo in the south to Apple River in the north. Chicago is the largest city by population.
| Zone | Cities | % |
|---|---|---|
| humid subtropical | 856 | 58.8% |
| warm-summer humid continental | 600 | 41.2% |
Microseason · September 21–25 · Predominantly Southeast Subtropical
Thunder quiets the land
Read this microseason across nine climate regions → · See all 72 microseasons
Microseason content for Illinois is drawn from the Southeast Subtropical corpus (59% of the state's cities sit in this region).
Live wind & temperature across Illinois
Cities in Illinois
| City | July normal | Population |
|---|---|---|
| Chicago | 76°F | 8,609,571 |
| Rockford | 74°F | 271,411 |
| Round Lake Beach | 75°F | 264,501 |
| Peoria | 76°F | 255,063 |
| Aurora | 76°F | 179,898 |
| Springfield | 78°F | 157,178 |
| Champaign | 75°F | 153,687 |
| Naperville | 76°F | 150,692 |
| Joliet | 76°F | 150,445 |
| Bloomington | 75°F | 135,296 |
| Palatine | 72°F | 66,293 |
| Willow Springs | 77°F | 5,868 |
| Lake Summerset | 72°F | 2,364 |
| Elizabeth | 72°F | 775 |
| Rankin | 75°F | 601 |
Our dataset lists 1,456 places in Illinois; the 15 above have a page. For a smaller town, the nearest city above is the closest match.