Last updated: March 2, 2024
Under the Köppen–Geiger climate classification Chicago features a humid continental climate (Dfa). Temperatures typically range between -3 °C (27 °F) and 24 °C (75 °F) through the year, but rarely can drop to -30 °C (-22 °F) or can rise to as high as 33 °C (92 °F). The average annual precipitation amounts to about 1193 mm (47.0 inches) and receives 134 rainy days on the 1 mm (0.04 inches) threshold annually. Chicago enjoys an average of 2979 hours of sunshine throughout the year, and daylight varies from 9 hours 10 minutes to 15 hours 9 minutes per day.
The warmest months in Chicago are June, July and August, with daily mean temperatures ranging from 21 to 24 °C (70 - 75 °F) throughout the day. The coldest temperatures usually occur in January, February and December, when daily mean temperatures range from -3 to 1 °C (27 - 34 °F) throughout the day. On average each year, Chicago experiences 70 days above 25 °C (77.0 °F) and 98 days below 0 °C (32.0 °F).
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Maximum | 14°C (57°F) |
18°C (64°F) |
23°C (74°F) |
26°C (79°F) |
32°C (90°F) |
33°C (91°F) |
33°C (92°F) |
33°C (92°F) |
32°C (90°F) |
29°C (85°F) |
22°C (73°F) |
18°C (64°F) |
| Mean maximum | 10°C (50°F) |
13°C (56°F) |
18°C (65°F) |
24°C (75°F) |
28°C (83°F) |
30°C (87°F) |
32°C (90°F) |
32°C (89°F) |
31°C (88°F) |
28°C (82°F) |
17°C (62°F) |
15°C (59°F) |
| Average high | 0°C (33°F) |
2°C (36°F) |
8°C (46°F) |
13°C (55°F) |
19°C (66°F) |
25°C (77°F) |
27°C (81°F) |
27°C (80°F) |
24°C (76°F) |
17°C (62°F) |
8°C (46°F) |
4°C (40°F) |
| Daily mean | -3°C (27°F) |
-2°C (29°F) |
4°C (39°F) |
8°C (47°F) |
15°C (59°F) |
21°C (70°F) |
24°C (75°F) |
23°C (73°F) |
20°C (68°F) |
13°C (55°F) |
4°C (40°F) |
1°C (34°F) |
| Average low | -6°C (22°F) |
-6°C (22°F) |
0°C (32°F) |
4°C (40°F) |
11°C (52°F) |
17°C (62°F) |
20°C (68°F) |
19°C (66°F) |
16°C (61°F) |
9°C (49°F) |
1°C (34°F) |
-2°C (28°F) |
| Mean minimum | -20°C (-3°F) |
-19°C (-2°F) |
-9°C (15°F) |
-3°C (28°F) |
3°C (38°F) |
12°C (55°F) |
15°C (60°F) |
14°C (57°F) |
9°C (49°F) |
1°C (35°F) |
-8°C (19°F) |
-11°C (12°F) |
| Minimum | -29°C (-21°F) |
-30°C (-22°F) |
-18°C (-1°F) |
-6°C (22°F) |
-1°C (31°F) |
10°C (50°F) |
14°C (58°F) |
11°C (53°F) |
6°C (42°F) |
-1°C (31°F) |
-14°C (6°F) |
-19°C (-2°F) |
Compare temperature, precipitation, sunshine, UV index in Chicago, Illinois, United States with other places around the world.
Chicago usually has the most precipitation in May, June and October, with an average of 13 rainy days and 147 mm (5.8 inches) of precipitation per month. The driest months in Chicago are January, November and December. On average, 65 mm (2.6 inches) of precipitation falls during these months.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Average precipitation mm (inches) | 68 (2.7) | 70 (2.7) | 95 (3.7) | 125 (4.9) | 156 (6.1) | 144 (5.7) | 104 (4.1) | 84 (3.3) | 78 (3.1) | 142 (5.6) | 65 (2.6) | 63 (2.5) |
| Average precipitation days (≥ 1 mm) | 9 | 12 | 11 | 13 | 15 | 13 | 12 | 11 | 9 | 13 | 8 | 8 |
The sunniest months in Chicago are June, July and August, when the sun shines an average of 11 hours 14 minutes a day. Least sunny months in Chicago: January, February and December receive an average of 5 hours 8 minutes of sunshine daily.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Mean monthly sunshine hours | 115 | 175 | 232 | 251 | 289 | 332 | 361 | 339 | 287 | 228 | 189 | 176 |
| Mean daily daylight hours | 9h 31m | 10h 35m | 11h 58m | 13h 22m | 14h 33m | 15h 9m | 14h 49m | 13h 46m | 12h 25m | 11h 1m | 9h 48m | 9h 10m |
Chicago experiences the highest level of ultraviolet (UV) radiation in June, July and August, when the maximum UV index can reach values of 9 - 10, which corresponds to the Very High category of sun exposure. January, February and December are in the Low / Moderate exposure category. In these months, the maximum values of the UV index do not exceed 4. For more detailed information, check out our hourly Chicago UV Index data.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| UV Index (month maximum) | 3 | 4 | 6 | 8 | 9 | 10 | 10 | 9 | 8 | 6 | 4 | 2 |
Discover in-depth weather details for every month in Chicago. Click through the links below for comprehensive overviews of temperature trends, precipitation levels, sunshine hours, and solar UV radiation specifics. Whether planning a visit or simply curious about Chicago's climate nuances, these monthly breakdowns provide the information you need for an informed understanding of what to expect throughout the year.
Each link leads to a detailed account of the typical weather conditions for that month, providing both locals and tourists with vital information to plan their daily activities, wardrobe, and travel itineraries accordingly.