Climateby Month

Chicago, IL climate by month

NOAA 1991-2020 normals · 588 ft elevation

Summers in Chicago are warm and often humid; winters are cold and snowy. Highs peak at 85°F in July and fall to 33°F in January. Wet days are spread through the year, from about 8 to 12 a month. Normal snowfall is about 39 in a year. The most comfortable time to visit is May and September.

Warmest month
85°F
July normal high
Coldest month
20°F
January normal low
Wet days a year
127
40.9 in of precipitation
Snow a year
38.8 in
normal snowfall

How warm is Chicago?

Normal highs range from 33°F in January to 85°F in July.

20°40°60°80°100° January: normal high 33°F (1°C), low 20°F (-7°C) 33° 20° February: normal high 37°F (3°C), low 23°F (-5°C) March: normal high 48°F (9°C), low 32°F (0°C) April: normal high 60°F (16°C), low 42°F (6°C) May: normal high 72°F (22°C), low 52°F (11°C) June: normal high 81°F (27°C), low 63°F (17°C) July: normal high 85°F (29°C), low 68°F (20°C) 85° 68° August: normal high 83°F (28°C), low 67°F (19°C) September: normal high 77°F (25°C), low 59°F (15°C) October: normal high 64°F (18°C), low 47°F (8°C) November: normal high 50°F (10°C), low 35°F (2°C) December: normal high 38°F (3°C), low 25°F (-4°C) JFMAMJJASOND

Bars run from the normal low to the normal high for each month.

How rainy is Chicago?

May has the most wet days (about 12); the year brings about 41 in of precipitation.

January: 12 wet days February: 9 wet days March: 11 wet days April: 12 wet days May: 12 wet days 12 June: 11 wet days July: 10 wet days August: 9 wet days September: 8 wet days 8 October: 11 wet days November: 10 wet days December: 11 wet days JFMAMJJASOND

Wet day: at least 0.01 in of rain or melted snow, counted from daily records 1991-2020.

How much does it snow?

Normal snowfall is 38.8 in a year, most of it in January.

January: 12.5 in of snow 12.5 February: 10.1 in of snow March: 5.7 in of snow April: 1.0 in of snow May: 0.0 in of snow 0.0 June: 0.0 in of snow July: 0.0 in of snow August: 0.0 in of snow September: 0.0 in of snow October: 0.1 in of snow November: 1.5 in of snow December: 7.9 in of snow JFMAMJJASOND

How humid is Chicago?

Muggy days peak in July, at about 12 days.

January: 0 muggy days 0 February: 0 muggy days March: 0 muggy days April: 0 muggy days May: 1 muggy days June: 6 muggy days July: 12 muggy days 12 August: 11 muggy days September: 3 muggy days October: 0 muggy days November: 0 muggy days December: 0 muggy days JFMAMJJASOND

Muggy day: daily mean dew point of 65°F or higher, from hourly observations 1991-2020 at Chicago Midway Intl Arpt, 7.1 mi SW of the city center.

How much daylight?

Daylight ranges from about 9.2 hours in December to 15.2 hours in June.

January: 9.5 hours of daylight February: 10.6 hours of daylight March: 12.0 hours of daylight April: 13.4 hours of daylight May: 14.6 hours of daylight June: 15.2 hours of daylight 15.2 July: 14.9 hours of daylight August: 13.8 hours of daylight September: 12.5 hours of daylight October: 11.1 hours of daylight November: 9.8 hours of daylight December: 9.2 hours of daylight 9.2 JFMAMJJASOND
See all numbers
Monthly climate normals and day counts for Chicago, 1991-2020
MonthHighLowPrecip.Wet daysSnowMuggy daysDaylight
January 33°F20°F 2.3 in12 12.5 in 0 9.5 h
February 37°F23°F 2.1 in9 10.1 in 0 10.6 h
March 48°F32°F 2.7 in11 5.7 in 0 12.0 h
April 60°F42°F 4.2 in12 1.0 in 0 13.4 h
May 72°F52°F 4.8 in12 0.0 in 1 14.6 h
June 81°F63°F 4.5 in11 0.0 in 6 15.2 h
July 85°F68°F 4.0 in10 0.0 in 12 14.9 h
August 83°F67°F 4.1 in9 0.0 in 11 13.8 h
September 77°F59°F 3.3 in8 0.0 in 3 12.5 h
October 64°F47°F 3.9 in11 0.1 in 0 11.1 h
November 50°F35°F 2.7 in10 1.5 in 0 9.8 h
December 38°F25°F 2.3 in11 7.9 in 0 9.2 h

High and low: NOAA 1991-2020 normal daily high and low. Wet days: at least 0.01 in of rain or melted snow. Muggy days: daily mean dew point 65°F or higher.

Best months to visit Chicago

By our comfort score, the best months are May and September.

Comfort score by month (0-100) and its parts, in days per month
MonthScoreComfortableNotable rainHot or cold
Jan 260624
Feb 320519
Mar 453610
Apr 60981
May 701481
Jun 641085
Jul 57668
Aug 58775
Sep 671562
Oct 591170
Nov 41367
Dec 290520

Score = 40 × share of comfortable days + 25 × share of days without notable rain + 20 × share of days neither hot (90°F+) nor cold (high 40°F or below) + 15 × daylight. How the score works.

Frost dates in Chicago

The last spring frost typically comes around Apr 11, and the first fall frost around Oct 31, leaving 201 frost-free days in a typical year.

Frost and freeze dates for Chicago
Typical date1 year in 10
Last spring frost (32°F)Apr 11after Apr 27
First fall frost (32°F)Oct 31before Oct 20
Last hard freeze (28°F)Apr 1after Apr 14
First hard freeze (28°F)Nov 11before Oct 31
Frost-free season201 daysunder 181 days

"Typical" is the date with a 50% chance of a later spring frost (or earlier fall frost). Planting after the "1 year in 10" spring date gives a 90% chance of no further frost. The Old Farmer's Almanac publishes 30% dates, which fall between our typical and 1-in-10 dates.

Station: Chicago Midway Airport (USW00014819), NOAA 1991-2020 freeze probabilities. Frost dates for every city in Illinois.

Hottest and coldest readings, 1991-2020

The highest reading was 106°F (July 13, 1995); the lowest was -22°F (January 30, 2019).

From the temperature station's daily records with NOAA quality flags removed. Not an all-time record.

Near Chicago

Similar climates elsewhere

Where the numbers come from

  • Temperature, rain, snowfall and snow depth: Chicago Midway Airport 3SW (USC00111577), 10 mi SW of the city center, 620 ft . NOAA normals and daily records, 1991-2020.
  • Frost dates and humidity and wind by hour: Chicago Midway Airport (USW00014819), 6.9 mi SW of the city center, 612 ft . NOAA normals and daily records, 1991-2020.
  • Daily humidity and wind: Chicago Midway Intl Arpt (725340-14819), 7.1 mi SW of the city center, 610 ft . Hourly observations, 1991-2020.
  • Not available for this location: cloud cover (no station close enough or similar enough in elevation).

Distances from the city center (USGS). Methodology · Report an error