Illinois weather by month
Average temperatures and rainfall across Illinois, based on 30 years of climate data.
Monthly climate (Chicago)
| Month | High / Low | Rainfall | Wet days |
|---|---|---|---|
| Jan | 31° / 19° | 2.4 in | 9.1 |
| Feb | 34° / 22° | 2.1 in | 7.5 |
| Mar | 44° / 30° | 2.8 in | 10.3 |
| Apr | 56° / 41° | 4.5 in | 12.4 |
| May | 67° / 52° | 4.3 in | 12.4 |
| Jun | 77° / 63° | 4.0 in | 12.1 |
| Jul | 82° / 67° | 3.6 in | 11.6 |
| Aug | 80° / 66° | 3.8 in | 10.9 |
| Sep | 73° / 58° | 3.0 in | 8.8 |
| Oct | 61° / 47° | 3.3 in | 9.5 |
| Nov | 47° / 35° | 2.8 in | 9 |
| Dec | 36° / 26° | 2.4 in | 8.7 |
Cities in Illinois
- 1Chicago25°–75°2.7MSep
- 2Aurora25°–73°201kSep
- 3Rockford23°–73°148kSep
- 4Joliet25°–75°148kSep
- 5Naperville25°–73°147kSep
- 6Peoria27°–75°115kSep
- 7Springfield28°–77°114kSep
- 8North Peoria27°–75°113kSep
- 9Elgin23°–73°112kSep
- 10Waukegan27°–73°88kAug
- 11West Town25°–75°86kSep
- 12Champaign28°–75°86kSep
- 13Near North Side25°–75°86kSep
- 14Cicero25°–75°84kSep
- 15Belmont Cragin25°–75°79kSep
- 16Bloomington27°–75°78kSep
- 17Arlington Heights25°–75°76kSep
- 18Evanston25°–75°76kSep
- 19Schaumburg25°–75°75kSep
- 20Bolingbrook25°–75°74kSep
- 21South Lawndale25°–75°74kSep
- 22Logan Square25°–75°74kSep
- 23Decatur28°–75°73kSep
- 24West Ridge25°–75°72kSep
- 25Palatine25°–75°69kSep
- 26Lincoln Park25°–75°67kSep
- 27Portage Park25°–75°65kSep
- 28Skokie25°–75°65kSep
- 29Des Plaines25°–75°59kSep
- 30Orland Park25°–75°59kSep
- 31Tinley Park25°–75°57kSep
- 32Oak Lawn25°–75°57kSep
- 33Irving Park25°–75°57kSep
- 34Berwyn25°–75°56kSep
- 35Chicago Lawn25°–75°56kSep
- 36Uptown25°–75°55kSep
- 37Edgewater25°–75°55kSep
- 38Mount Prospect25°–75°55kSep
- 39Rogers Park25°–75°54kSep
- 40Normal27°–75°54kSep
- 41Wheaton25°–75°54kSep
- 42Oak Park25°–75°52kSep
- 43Hoffman Estates25°–75°52kSep
- 44Albany Park25°–75°52kSep
- 45South Shore27°–75°51kSep
- 46Downers Grove25°–75°50kSep
- 47Glenview25°–75°47kSep
- 48Elmhurst25°–75°46kSep
- 49Auburn Gresham25°–75°46kSep
- 50Brighton Park25°–75°44kSep
- 51Lombard25°–75°44kSep
- 52DeKalb23°–73°43kSep
- 53Ashburn25°–75°43kSep
- 54Moline23°–75°43kSep
- 55Plainfield25°–73°43kSep
- 56Urbana28°–75°42kSep
- 57Belleville32°–79°42kSep
- 58Bartlett23°–73°42kSep
- 59Buffalo Grove25°–73°41kSep
- 60Gage Park25°–75°41kSep
- 61New City25°–75°41kSep
- 62Quincy28°–77°41kSep
- 63Lincoln Square25°–75°41kSep
- 64Streamwood23°–73°41kSep
- 65Crystal Lake23°–73°40kSep
- 66Carol Stream23°–73°40kSep
- 67Avondale25°–75°40kSep
- 68Romeoville25°–75°40kSep
- 69Rock Island23°–75°39kSep
- 70Carpentersville23°–73°39kSep
- 71Hanover Park23°–73°38kSep
- 72Wheeling25°–73°38kSep
- 73Park Ridge25°–75°38kSep
- 74Addison25°–75°37kSep
- 75Calumet City27°–75°37kSep
- 76North Lawndale25°–75°35kSep
- 77North Center25°–75°35kSep
- 78Lower West Side25°–75°34kSep
- 79Glendale Heights25°–75°34kSep
- 80Oswego25°–73°34kSep
- 81Bridgeport25°–75°34kSep
- 82Northbrook27°–73°34kAug
- 83Chicago Loop25°–75°33kSep
- 84Woodridge25°–75°33kSep
- 85Elk Grove Village25°–75°33kSep
- 86Pekin27°–75°33kSep
- 87St. Charles23°–73°33kSep
- 88West Lawn25°–75°33kSep
- 89Greater Grand Crossing27°–75°32kSep
- 90West Englewood25°–75°32kSep
- 91Danville28°–75°32kSep
- 92Mundelein25°–73°32kSep
- 93Chatham27°–75°31kSep
- 94Galesburg25°–75°31kSep
- 95Gurnee25°–73°31kSep
- 96Algonquin23°–73°31kSep
- 97Chicago Heights25°–75°30kSep
- 98Niles25°–75°30kSep
- 99Highland Park27°–73°30kAug
- 100North Chicago27°–73°29kAug
- 101Upper Alton30°–79°29kSep
- 102Burbank25°–75°29kSep
- 103Granite City32°–79°29kSep
- 104Lake in the Hills23°–73°29kSep
- 105O'Fallon32°–79°29kSep
- 106Lansing27°–75°28kSep
- 107Glen Ellyn25°–75°28kSep
- 108South Chicago27°–75°28kSep
- 109Oak Forest25°–75°28kSep
- 110Round Lake Beach25°–73°28kSep
- 111West Chicago23°–73°27kSep
- 112Wilmette25°–75°27kSep
- 113East Saint Louis32°–79°27kSep
- 114Alton30°–79°27kSep
- 115Hyde Park27°–75°27kSep
- 116Kankakee27°–75°27kSep
- 117McHenry23°–73°27kSep
- 118Batavia25°–73°26kSep
- 119Carbondale36°–79°26kSep
- 120Vernon Hills25°–73°26kSep
- 121Englewood25°–75°26kSep
- 122Huntley23°–73°26kSep
- 123New Lenox25°–75°26kSep
- 124Melrose Park25°–75°25kSep
- 125Harvey25°–75°25kSep
- 126Woodstock23°–73°25kSep
- 127Lockport25°–75°25kSep
- 128Belvidere23°–73°25kSep
- 129Edwardsville32°–79°25kSep
- 130Westmont25°–75°25kSep
- 131Elmwood Park25°–75°25kSep
- 132Collinsville32°–79°25kSep
- 133Freeport21°–73°24kSep
- 134Homer Glen25°–75°24kSep
- 135Rolling Meadows25°–75°24kSep
- 136Woodlawn27°–75°24kSep
- 137Zion25°–73°24kJul
- 138Maywood25°–75°24kSep
- 139Blue Island25°–75°24kSep
- 140Loves Park23°–73°23kSep
- 141Morton Grove25°–75°23kSep
- 142Dolton27°–75°23kSep
- 143East Peoria27°–75°23kSep
- 144Roselle25°–75°23kSep
- 145Lisle25°–75°23kSep
- 146Machesney Park23°–73°23kSep
- 147Morgan Park25°–75°23kSep
- 148Wasco23°–73°23kSep
- 149Near South Side27°–75°22kSep
- 150Grand Boulevard27°–75°22kSep
- 151South Elgin23°–73°22kSep
- 152Darien25°–75°22kSep
- 153Bloomingdale25°–75°22kSep
- 154South Holland27°–75°22kSep
- 155Villa Park25°–75°22kSep
- 156Park Forest25°–75°22kSep
- 157Geneva23°–73°22kSep
- 158East Moline23°–75°21kSep
- 159Charleston30°–77°21kSep
- 160Crest Hill25°–75°21kSep
- 161Grayslake25°–73°21kSep
- 162East Garfield Park25°–75°21kSep
- 163Libertyville25°–73°20kSep
- 164Douglas27°–75°20kSep
- 165Lake Zurich25°–73°20kSep
- 166Mokena25°–75°20kSep
- 167Evergreen Park25°–75°20kSep
- 168Montgomery25°–73°19kSep
- 169Lake Forest27°–73°19kAug
- 170Homewood25°–75°19kSep
- 171Alsip25°–75°19kSep
- 172Bellwood25°–75°19kSep
- 173West Elsdon25°–75°19kSep
- 174Matteson25°–75°19kSep
- 175Jacksonville28°–77°19kSep
- 176Deerfield27°–73°19kAug
- 177Brookfield25°–75°19kSep
- 178Mount Greenwood25°–75°19kSep
- 179Frankfort25°–75°19kSep
- 180Bourbonnais25°–75°19kSep
- 181Goodings Grove25°–75°19kSep
- 182Macomb27°–75°19kSep
- 183Round Lake25°–73°18kSep
- 184Yorkville25°–73°18kSep
- 185Bensenville25°–75°18kSep
- 186Ottawa25°–75°18kSep
- 187Franklin Park25°–75°18kSep
- 188Mattoon30°–77°18kSep
- 189Cary23°–73°18kSep
- 190Marion36°–79°18kSep
- 191Godfrey30°–79°18kSep
- 192West Garfield Park25°–75°18kSep
- 193Sycamore23°–73°18kSep
- 194Hinsdale25°–75°18kSep
- 195Kenwood27°–75°18kSep
- 196Palos Hills25°–75°18kSep
- 197North Aurora25°–73°17kSep
- 198Fairview Heights32°–79°17kSep
- 199Country Club Hills25°–75°17kSep
- 200Lemont25°–75°17kSep
- 201Shorewood25°–75°17kSep
- 202Westchester25°–75°17kSep
- 203Washington27°–75°17kSep
- 204Bridgeview25°–75°16kSep
- 205Prospect Heights25°–75°16kSep
- 206Morton27°–75°16kSep
- 207La Grange25°–75°16kSep
- 208Bradley27°–75°16kSep
- 209McKinley Park25°–75°16kSep
- 210Dixon23°–73°15kSep
- 211Mount Vernon34°–79°15kSep
- 212Sterling23°–75°15kSep