Chicago, IL Climate & Monthly Averages
The climate of Chicago
The Chicago year is defined by how long its winter lasts: 4 months average sub-freezing nights, bottoming out in January at 20°F (-6°C). Summer is the short exception, with July reaching 80°F (27°C).
Climate quick facts
- Hottest month: July - highs near 80°F (27°C)
- Coldest month: January - highs near 32°F (0°C)
- Decade extremes (2015-2024): 99°F (37°C) high · -26°F (-32°C) low
- Wettest month: July (12 rainy days) · Sunniest: July (11.8 h sun/day)
- Climate type: humid continental
- Annual swing: 26°C between the average warmest and coolest month · day to night: 8°C
- Snow: about 18 days a year
- Months with freezing average lows: 4
- Average humidity: 74%
Temperatures through the year
Precipitation concentrates in July - 6.0 inches (152 mm) on 12 days - and thins out by February. January bottoms out at 32°F (0°C) in daylight, 20°F (-6°C) after dark. At its warmest, in July, Chicago runs to 80°F (27°C) in the afternoon and back to 67°F (19°C) by dawn. Across the gridded 2015-2024 daily record, the highest daily maximum for this location was 99°F (37°C) and the lowest daily minimum -26°F (-32°C). Between the average July and the average January lie 26°C, a wider spread than roughly 88% of the cities we track.
Rain, sun and snow
Sunshine averages 8.5 hours a day over the year, peaking in July at 11.8 hours. Overnight lows average at or below freezing for 4 months, December through March.
How Chicago compares
- Chicago sits close to the middle of our dataset on most measures: 51°F (10°C) as an annual average, 46.3 inches (1177 mm) of precipitation and 8.5 hours of sun a day.
Ranked against every city in our dataset, each measured on the same ten-year window.
Monthly climate table
| Month | High | Low | Rain days | Precipitation | Sunshine | Daylight | Wet-day chance | Humidity |
|---|---|---|---|---|---|---|---|---|
| January | 32° | 20° | 10 | 2.6 in | 4.9 h/day | 9.5 h | 34% | 76% |
| February | 36° | 20° | 9 | 2.4 in | 6.8 h/day | 10.5 h | 32% | 73% |
| March | 45° | 31° | 11 | 3.5 in | 7.9 h/day | 11.8 h | 36% | 74% |
| April | 54° | 39° | 14 | 4.2 in | 8.8 h/day | 13.3 h | 47% | 73% |
| May | 66° | 50° | 13 | 5.3 in | 10.1 h/day | 14.5 h | 41% | 76% |
| June | 77° | 61° | 12 | 4.5 in | 11.6 h/day | 15.2 h | 40% | 73% |
| July | 80° | 67° | 12 | 6.0 in | 11.8 h/day | 14.9 h | 39% | 77% |
| August | 80° | 66° | 12 | 4.2 in | 11.5 h/day | 13.8 h | 38% | 76% |
| September | 75° | 62° | 10 | 3.8 in | 9.6 h/day | 12.4 h | 33% | 74% |
| October | 62° | 49° | 12 | 4.8 in | 7.5 h/day | 11.0 h | 38% | 72% |
| November | 48° | 36° | 8 | 2.5 in | 6.0 h/day | 9.8 h | 26% | 73% |
| December | 39° | 28° | 9 | 2.6 in | 5.0 h/day | 9.1 h | 28% | 75% |
Chicago month by month
Average high and low for each month, with the bar showing where it sits in Chicago's year (left is the coldest night, right is the warmest afternoon).
January
- Rain
- 10 days
- Sunshine
- 4.9 h
- Daylight
- 9.5 h
- Snow
- 6 days
February
- Rain
- 9 days
- Sunshine
- 6.8 h
- Daylight
- 10.5 h
- Snow
- 4 days
March
- Rain
- 11 days
- Sunshine
- 7.9 h
- Daylight
- 11.8 h
- Snow
- 2 days
April
- Rain
- 14 days
- Sunshine
- 8.8 h
- Daylight
- 13.3 h
- Snow
- 2 days
May
- Rain
- 13 days
- Sunshine
- 10.1 h
- Daylight
- 14.5 h
June
- Rain
- 12 days
- Sunshine
- 11.6 h
- Daylight
- 15.2 h
July
- Rain
- 12 days
- Sunshine
- 11.8 h
- Daylight
- 14.9 h
August
- Rain
- 12 days
- Sunshine
- 11.5 h
- Daylight
- 13.8 h
September
- Rain
- 10 days
- Sunshine
- 9.6 h
- Daylight
- 12.4 h
October
- Rain
- 12 days
- Sunshine
- 7.5 h
- Daylight
- 11.0 h
November
- Rain
- 8 days
- Sunshine
- 6.0 h
- Daylight
- 9.8 h
- Snow
- 1 day
December
- Rain
- 9 days
- Sunshine
- 5.0 h
- Daylight
- 9.1 h
- Snow
- 3 days
Warmer places to go, by month: January · February · March · April · May · June · July · August · September · October · November · December
Seasons in Chicago
Spring (March through May)
Spring is mild here - highs near 55°F (13°C), nights near 40°F (5°C), and rain falls on around 38 of the 90 days, plus about 4 snowy days.
Summer (June through August)
Summer in Chicago settles into easy warmth, with daytime highs averaging 79°F (26°C) and nights around 65°F (18°C); rain falls on around 36 of the 90 days. Daylight is generous - around 11.6 hours of sun a day.
Fall (September through November)
Fall runs cool rather than cold here - highs near 62°F (16°C), nights near 49°F (9°C), and expect showers on roughly 30 days across the season.
Winter (December through February)
Through winter, Chicago is bitterly cold: 36°F (2°C) by day, 23°F (-5°C) after dark, and expect showers on roughly 28 days across the season, plus about 13 snowy days. Wind sharpens cold like this considerably; pair the forecast winds with the wind speed converter to judge exposed conditions.
Climate questions, answered
How hot does Chicago get in summer?
What should I pack for Chicago?
Does it freeze in Chicago?
How warm is Chicago on average?
How cold does Chicago get in winter?
How many rainy days does Chicago get in a year?
Best time to visit Chicago
The best time to visit Chicago is generally May to October, when these are the warmest and brightest weeks of the year. Daytime temperatures in that window sit near 73°F (23°C), with rain on about 12 days a month. For the same question asked the other way round, see where else is warm in May.
Pack for Chicago with a heavy insulated coat, hat and gloves for winter and a compact umbrella or rain shell. Even in July, lows of 67°F (19°C) make an extra layer worth the space.
Chicago temperature records (2015-2024)
Derived from ERA5 reanalysis data, 2015–2024. Official station records may differ. Need the precipitation in other units? The mm-to-inches rainfall converter handles it.