Chicago Weather Averages

Chicago, Illinois experiences a wide range of temperatures, with blasts of cold weather in winter and hot days in summer. Meanwhile precipitation in the city remains fairly steady. Year round, one in three days have some rain or snow. The rain comes down more heavily though from May to August.

This page gives detailed information on the annual temperature, precipitation, sun, humidity, wind and storms averages for Chicago. The numbers here are historical averages based on temperature, rain and snow measurements gathered at Chicago Midway Airport and other climate data from Chicago O'Hare International Airport.

Temperature Weather iconTemperature

61 °F annual average high 16 °C
44 °F annual average low 7 °C

Chicago's coldest days of the year usually occur in the second half of January when the daily maximum temperature averages 32 degrees Fahrenheit (0 degrees Celsius) and the minimum averages 19 °F (-7 °C).

The year's hottest days are normally in mid July. The average temperature peaks then with daily highs of 86 °F (30 °C) and nighttime lows of 68 °F (20 °C).

145 days 70 °F max. or more (21 °C)
108 days 32 °F min. or less (0 °C)

Chicago averages 21 days a year when the thermometer reaches into the 90s °F (over 32 °C). The temperature can climb briefly above 100 °F (38 °C) although days that hot don't occur every year. Typically on 39 days annually the thermometer remains below freezing for the entire day.

The temperature drops to 10 °F (-12 °C) or below on 16 nights a year. In an average year, Chicago has 4 nights down to 0 °F (-18 °C) or even colder.

Rainy Weather iconPrecipitation

40.9 in total precipitation 1038 mm
127 days of rain or snowfall

May is usually the wettest month of the year in Chicago, while winter months are the driest.

Snowy Weather iconSnow

38.4 in total snowfall 98 cm
28 days with new snow

Most years, it snows in Chicago from November to April. The snowpack accumulates to at least 3 inches (8 cm) deep on an average of 26 days annually.

Sunny Weather iconSun

54 % sunshine
84 days clear skies

The sun's rays reach the ground in Chicago during 54 percent of daylight hours on average year round, for a total of 2407 hours annually. Typically on 84 days a year the sky is mainly clear, with at most 30 percent cloud cover.

Sunlight in Chicago averages 12 hours and 12 minutes a day. The shortest days of the year in mid December have 9 hours and 8 minutes of daylight. The year's longest days in mid June last 15:13 from sunrise to sunset.

Humid Weather iconHumidity

70 % average humidity

The annual average for relative humidity in Chicago ranges throughout the day from 80 percent at 6:00 am to 57 percent at 3:00 pm.

Local Time12 am3 am6 am9 am12 pm3 pm6 pm9 pm
Humidity % 77 79 80 69 60 57 63 72

Windy Weather iconWind

10.3 mph wind speed average 16.6 kph

April is usually the windiest month for Chicago, while the wind is calmest during August.

Stormy Weather iconStorms

10 days precipitation of 1 inch (25 mm) or more
4 days snowfall of 3 inches (8 cm) or more
38 days with thunderstorms a year

Storms that blanket Chicago in over 10 inches (25 cm) of snow during a single day appear about once a decade.

Thunderstorms usually pass over Chicago from March to November, although they can appear in any month.


The weather data here are long-term averages provided by the US National Centers for Environmental Information (NCEI). Temperature and precipitation are 1991-2020 normals while humidity and thunderstorms are 1961-1990 normals.

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