Chicago features a classic humid continental climate with four distinct seasons: hot, humid summers, cold and snowy winters, and mild, changeable spring and autumn. The city is known for its unpredictable weather, brisk winds from Lake Michigan, and dramatic temperature swings, making each season a unique experience for residents and visitors alike.
The best times to travel section shows how the months compare for a visit, so you can find the time of year that fits what you want to do.
Background colours of the months:
The colour shows the typical temperature: yellow (hot), green (mild) and blue (cold). How strong the colour is shows the travel season: full colour means high season, soft colour means shoulder season and soft-striped means off season.
Weather symbols:
Each month has one symbol showing what the weather is typically like, such as hot and sunny, freezing or a rainy or snowy season. Use them to quickly spot months that match the weather you want, or to avoid the ones that don't.
Crowdedness:
The people icon shows how busy the place usually is. The more people, the more crowded it gets.
Additional notes:
The grey info boxes point out special things worth knowing, like recurring weather issues or seasonal events.
Chicago’s climate is shaped by its inland location and proximity to Lake Michigan, resulting in pronounced seasonal contrasts. Summers (June–August) are warm to hot and humid, with average highs of 27–29°C in July, but temperatures can soar above 33°C during heatwaves. Thunderstorms are common in summer, and the lake often moderates temperatures, keeping shoreline areas cooler than inland neighbourhoods. Summer is also the sunniest season, with up to 10 hours of sunshine per day and frequent breezes, earning Chicago its 'Windy City' nickname.
Winters (December–February) are cold and often snowy, with average highs of -1°C to 1°C and lows frequently below freezing. Snowfall is common, with an annual average of 95–100 cm, and blizzards or 'lake effect' snow can occasionally blanket the city. Wind chills can make temperatures feel much colder, and extreme cold snaps can push lows below -18°C. Spring (March–May) and autumn (September–November) are transitional and highly variable, featuring mild days, cool nights, and rapid weather changes. Spring brings blooming parks and frequent rain, while autumn is known for vibrant foliage and crisp, sunny days. Rainfall is moderate and fairly evenly distributed, with the wettest months typically in late spring and early summer.
Daylight varies from about 9 hours in winter to 15 hours in summer. Winds are a constant feature, especially in spring, with average speeds of 13–19 km/h but often stronger on blustery days. The city’s 30+ beaches along Lake Michigan are popular in summer, though the lake remains chilly year-round. Chicago’s weather is famously unpredictable – locals recommend dressing in layers and always checking the forecast before heading out.
| Average climate data for Chicago, United States | |||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Month | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | Year |
| Average maximum temperature (°C) | -1 | -0 | 5 | 10 | 16 | 21 | 25 | 25 | 22 | 15 | 8 | 2 | 25 |
| Average minimum temperature (°C) | -6 | -5 | 0 | 5 | 10 | 16 | 20 | 20 | 16 | 9 | 3 | -2 | -6 |
| Average precipitation (mm) | 45 | 45 | 53 | 94 | 118 | 124 | 106 | 103 | 82 | 79 | 46 | 43 | 938 |
| Average rainfall days (days) | 7 | 5 | 12 | 17 | 18 | 17 | 19 | 17 | 15 | 14 | 10 | 9 | 160 |
| Average snowfall (mm) | 87 | 91 | 34 | 42 | 2 | 0 | 0 | 0 | 0 | 0 | 36 | 64 | 355 |
| Average snowfall days (days) | 11 | 10 | 6 | 2 | 0 | 0 | 0 | 0 | 0 | 0 | 4 | 7 | 41 |
| Average relative humidity (%) | 82 | 80 | 78 | 76 | 79 | 79 | 78 | 75 | 75 | 72 | 73 | 81 | 77 |
| Average wind speed (km/h) | 20 | 19 | 18 | 18 | 15 | 13 | 13 | 13 | 15 | 18 | 19 | 19 | 17 |
| Average water temperature (°C) | 4 | 3 | 3 | 5 | 7 | 14 | 22 | 23 | 20 | 15 | 10 | 6 | 11 |
| Average daily daylight hours (h) | 9 | 10 | 12 | 13 | 14 | 15 | 14 | 13 | 12 | 11 | 9 | 9 | 12 |
| Average daily sunshine hours (h) | 3 | 3 | 6 | 7 | 8 | 10 | 10 | 10 | 9 | 5 | 5 | 4 | 7 |
| Average cloud coverage (%) | 61 | 59 | 50 | 48 | 41 | 33 | 28 | 27 | 30 | 40 | 46 | 57 | 43 |
| Average UV index | 1 | 2 | 2 | 3 | 4 | 5 | 6 | 6 | 4 | 2 | 2 | 1 | 3 |
The best time to visit Chicago is late spring (May–June) and early autumn (September–early October), when temperatures are mild (15–24°C), humidity is lower, and the city’s parks and lakefront are vibrant. These seasons offer ideal weather for sightseeing, outdoor festivals, and exploring Chicago’s neighbourhoods before the extremes of summer heat or winter cold.
The least favourable time to visit is during winter (December–February), when temperatures often remain below freezing, snow and wind chills are common, and daylight hours are short. While the city’s holiday lights and indoor attractions are appealing, outdoor activities can be uncomfortable due to the cold and unpredictable weather.
Chicago experiences a humid continental climate with hot, humid summers, cold, snowy winters, and mild spring and autumn. The city is known for its dramatic seasonal changes and brisk winds from Lake Michigan.
Summer highs typically reach 27–29°C in July and August, but heatwaves can push temperatures above 33°C. Humidity is high, and thunderstorms are common, especially in late spring and summer.
Yes, Chicago receives about 95–100 cm of snow each winter. Snowfall is common from December to March, and blizzards or 'lake effect' snow can bring heavy accumulations and travel disruptions.
Rainfall is moderate and fairly evenly spread, but the wettest months are typically May to August. Thunderstorms are frequent in summer, while spring and autumn see more steady rain.
Yes, Chicago is known as the 'Windy City.' Winds are especially strong in spring and along the lakefront, with average speeds of 13–19 km/h but often higher during storms or cold fronts.
Pack layers for rapid weather changes. In summer, bring light clothing, sun protection, and a rain jacket. For winter, warm layers, insulated boots, gloves, and windproof outerwear are essential. Waterproof shoes are useful year-round.
Chicago has over 30 sandy beaches along Lake Michigan, popular in summer. However, lake water remains cool, averaging 16–21°C in summer. Swimming is best from late June to August, but check local advisories before entering the water.
The warmest month, with the highest average maximum temperature, is August (25.3 °C). The month with the lowest average maximum temperature is January (-1.3 °C). Overall, the average maximum temperature over the whole year is 12.5 °C.
The month with the highest average minimum temperature is July (20 °C). The coldest month, with the lowest average minimum temperature, is January (-6.3 °C). Overall, the average minimum temperature over the whole year is 7.1 °C.
The month with the highest average water temperature is August (23.3 °C). The month with the lowest average water temperature is February (2.7 °C). Overall, the average water temperature over the whole year is 11 °C.
The wettest month, with the highest amount of precipitation, is June (124 mm). The driest month, with the least amount of precipitation, is December (42.5 mm). Over the whole year there are 938.3 mm of rainfall on average.
The month with the most days of rain is July (18.6 days). The month with the fewest days of rain is February (5.4 days). Over the whole year there are 160.1 days of rain on average.
The month with the most snowfall is February (90.5 mm). The months with the least snowfall are June, July, August, September and October (0 mm). Over the whole year there are 354.8 mm of snowfall on average.
The month with the most days of snowfall is January (10.6 days). The month with the fewest days of snowfall is August (0 days). Over the whole year there are 40.7 days of snowfall on average.
The month with the highest average relative humidity is January (82.1 %). The month with the lowest average relative humidity is October (72.2 %). The overall average relative humidity over the whole year is 77.4 %.
The windiest month, with the highest average wind speed, is January (19.9 km/h). The calmest month, with the lowest average wind speed, is July (12.5 km/h). The overall average wind speed over the whole year is 16.6 km/h.
The month with the cloudiest skies, so the highest cloud coverage, is January (61.5 %). The month with the clearest skies, so the lowest cloud coverage, is August (26.7 %). Over the whole year there is an average cloud coverage of 43.4 %.
The month with the longest days, so the most daylight, is June (Average daylight: 15 h). The month with the shortest days, so the least daylight, is December (Average daylight: 9 h). Over the whole year there are 11.8 h of daylight per day on average.
The month with the most sunshine per day is July (Average sunshine: 10.1 h). The month with the least sunshine per day is January (Average sunshine: 3 h). Over the whole year there are 6.7 h of sunlight per day on average.
The months with the highest average UV index are July and August (UV index: 6). The months with the lowest average UV index are January and December (UV index: 1). Over the whole year the average UV index is 3.2.
