- WinterDec–Feb22°36°
- December25°38°
- January20°33°
- February22°36°
- SpringMar–May42°60°
- March32°48°
- April42°60°
- May52°71°
- SummerJun–Aug66°83°
- June63°81°
- July68°85°
- August66°83°
- AutumnSep–Nov47°63°
- September59°76°
- October47°63°
- November35°50°
Chicago, IL Weather by Month and Climate Averages
Chicago, IL gets 34.4 in of precipitation a year over about 121 rainy days. July is the warmest month (average high 85°F) and January the coldest (average low 20°F).
Chicago climate at a glance
Humid continental climate
Chicago, IL has hot summers and cold winters. Daytime highs range from about 33°F in January to 85°F in July. May is usually the wettest month. The most comfortable time to visit is typically September to October, when daytime highs sit near 70°F.
How much rain does Chicago get?
Chicago gets 34.4 in of precipitation in an average year, spread over about 121 days with measurable rain. That is more rainy days than 79% of the US.
May is the wettest month, with 4.1 in. February is the driest, with 1.5 in. May has the most rainy days, about 13.
The longest dry spell in the last five years lasted 22 days, to December 13, 2024.
See where Chicago ranks: rainiest cities in the US, US cities with the most rainy days, rainiest cities in Illinois.
Chicago weather by month
Chicago weather in January
In January, Chicago averages a high of 33°F and a low of 20°F. It gets 1.5 in of precipitation over about 8 rainy days. The sun is out about 22% of daylight hours. The January record high is 65°F (2008) and the record low is -22°F (2019).
Chicago weather in February
In February, Chicago averages a high of 36°F and a low of 22°F. It gets 1.5 in of precipitation over about 8 rainy days. The sun is out about 40% of daylight hours. The February record high is 74°F (2024) and the record low is -9°F (2007).
Chicago weather in March
In March, Chicago averages a high of 48°F and a low of 32°F. It gets 1.9 in of precipitation over about 10 rainy days. The sun is out about 34% of daylight hours. The March record high is 86°F (2012) and the record low is -4°F (2002).
Chicago weather in April
In April, Chicago averages a high of 60°F and a low of 42°F. It gets 3.6 in of precipitation over about 12 rainy days. The sun is out about 37% of daylight hours. The April record high is 89°F (2002) and the record low is 21°F (2018).
Chicago weather in May
In May, Chicago averages a high of 71°F and a low of 52°F. It gets 4.1 in of precipitation over about 13 rainy days. The sun is out about 38% of daylight hours. The May record high is 97°F (2012) and the record low is 31°F (2020).
Chicago weather in June
In June, Chicago averages a high of 81°F and a low of 63°F. It gets 4.0 in of precipitation over about 12 rainy days. The sun is out about 50% of daylight hours. The June record high is 101°F (2022) and the record low is 39°F (2003).
Chicago weather in July
In July, Chicago averages a high of 85°F and a low of 68°F. It gets 3.5 in of precipitation over about 10 rainy days. The sun is out about 48% of daylight hours. The July record high is 104°F (2012) and the record low is 54°F (1997).
Chicago weather in August
In August, Chicago averages a high of 83°F and a low of 66°F. It gets 4.0 in of precipitation over about 10 rainy days. The sun is out about 52% of daylight hours. The August record high is 100°F (2023) and the record low is 49°F (2009).
Chicago weather in September
In September, Chicago averages a high of 76°F and a low of 59°F. It gets 2.8 in of precipitation over about 9 rainy days. The sun is out about 53% of daylight hours. The September record high is 96°F (2013) and the record low is 42°F (2014). September is one of the most comfortable months to visit.
Chicago weather in October
In October, Chicago averages a high of 63°F and a low of 47°F. It gets 3.5 in of precipitation over about 11 rainy days. The sun is out about 48% of daylight hours. The October record high is 90°F (2025) and the record low is 26°F (2019). October is one of the most comfortable months to visit.
Chicago weather in November
In November, Chicago averages a high of 50°F and a low of 35°F. It gets 2.4 in of precipitation over about 9 rainy days. The sun is out about 43% of daylight hours. The November record high is 77°F (2016) and the record low is 9°F (2019).
Chicago weather in December
In December, Chicago averages a high of 38°F and a low of 25°F. It gets 1.8 in of precipitation over about 9 rainy days. The sun is out about 30% of daylight hours. The December record high is 72°F (2012) and the record low is -9°F (2022).
Sunshine, humidity and wind in Chicago
September is the sunniest month in Chicago, with sunshine about 53% of daylight hours. January is the cloudiest, at 22%. Over the year the sun shines about 41% of daylight hours. Chicago is cloudier than 84% of the US.
Humidity peaks in January at 77% and is lowest in April at 63%.
Wind averages 10 mph over the year, and April is the windiest month at 11 mph.
Chicago has about 21 days a year above 90°F. Chicago is cooler than 60% of the US.
Thunderstorms occur on about 35 days a year.
See where Chicago ranks: sunniest cities in the US, cloudiest cities in the US, hottest cities in the US.
First and last freeze in Chicago
The first fall freeze in Chicago typically comes around November 1, and the last spring freeze around April 10. That leaves a frost-free growing season of about 205 days.
Chicago weather records
The hottest temperature on record at the Chicago station is 104°F, on July 30, 1999. The coldest is -22°F, on January 30, 2019.
The wettest day on record brought 5.2 in of rain, on October 14, 2017.
33 all-time records have been set at the station since 1997.
The best time to visit Chicago
The most comfortable time to visit is typically September to October, when daytime highs sit near 70°F.
Winter (December–February) is cold, with average highs around 36°F and lows near 22°F.
Spring (March–May) is mild, with average highs around 60°F and lows near 42°F.
Summer (June–August) is hot, with average highs around 83°F and lows near 66°F. It can feel humid.
Autumn (September–November) is mild, with average highs around 63°F and lows near 47°F.
Monthly climate
| Month | Precip | Rain days | Wind | Humidity | Sunshine | Sea temp | Record high | Record low |
|---|---|---|---|---|---|---|---|---|
| January | 1.5 in | 8 | 11 mph | 77% | 22% | 36° | 65° | -22° |
| February | 1.5 in | 8 | 11 mph | 68% | 40% | 33° | 74° | -9° |
| March | 1.9 in | 10 | 11 mph | 66% | 34% | 33° | 86° | -4° |
| April | 3.6 in | 12 | 11 mph | 63% | 37% | 38° | 89° | 21° |
| May | 4.1 in | 13 | 10 mph | 65% | 38% | 47° | 97° | 31° |
| June | 4.0 in | 12 | 9 mph | 65% | 50% | 60° | 101° | 39° |
| July | 3.5 in | 10 | 8 mph | 73% | 48% | 69° | 104° | 54° |
| August | 4.0 in | 10 | 8 mph | 72% | 52% | 71° | 100° | 49° |
| September | 2.8 in | 9 | 9 mph | 69% | 53% | 68° | 96° | 42° |
| October | 3.5 in | 11 | 10 mph | 66% | 48% | 59° | 90° | 26° |
| November | 2.4 in | 9 | 10 mph | 67% | 43% | 49° | 77° | 9° |
| December | 1.8 in | 9 | 10 mph | 72% | 30% | 41° | 72° | -9° |
From ERA5 reanalysis. Sunshine is estimated from cloud cover.
Chicago climate questions
How much rain does Chicago get?
Chicago gets 34.4 in of precipitation in an average year, over about 121 rainy days.
What is the wettest month in Chicago?
May is the wettest month in Chicago, with 4.1 in. February is the driest, with 1.5 in.
How many rainy days does Chicago have a year?
Chicago has about 121 days with measurable rain in an average year. May has the most, about 13.
What is the hottest month in Chicago?
July is the warmest month in Chicago, with an average high of 85°F.
What is the coldest month in Chicago?
January is the coldest month in Chicago, with an average low of 20°F.
What is the record high temperature in Chicago?
The record high at the Chicago station is 104°F, set on July 30, 1999. The record low is -22°F, on January 30, 2019.
What is the sunniest month in Chicago?
September is the sunniest month in Chicago, with sunshine about 53% of daylight hours. January is the cloudiest.
When is the first frost in Chicago?
The first fall freeze in Chicago typically comes around November 1. The last spring freeze is around April 10.
What is the best time to visit Chicago?
The most comfortable time to visit is typically September to October, when daytime highs sit near 70°F.
Source: NOAA GHCN-Daily station CHICAGO MIDWAY AP (11 km away).
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Climate for places near Chicago, IL
Normals from NOAA GHCN-Daily station CHICAGO MIDWAY AP.