Chicago Temperatures: Averages by Month





The numbers here tell you how hot and cold the weather usually is in Chicago, Illinois during each month of the year.

The average high and low temperatures are listed below by month and annually for Chicago, in both degrees Fahrenheit and Celsius.

Maximums and minimums are only part of the temperature picture. To fill in the rest, there's information on how many days a month get above or below a given temperature.

To find out how often it rises over 70, 80 or 90 °F each month in Chicago, scroll down farther. There are also monthly and yearly counts of days with freezing weather.

The first set of high and low temperatures are averages for 2010 to 2019. Everything else here is based on 1981 to 2010 weather.

10-year temperature averages for Chicago, 2010 to 2019
High °F Low °F   High °C Low °C
31 17 January -1 -9
35 19 February 1 -7
47 30 March 8 -1
59 39 April 15 4
71 51 May 22 10
80 61 June 27 16
85 66 July 29 19
83 65 August 28 18
76 58 September 24 14
63 45 October 17 7
48 32 November 9 0
37 24 December 3 -4
59 42 Year 15 6
30-year temperature averages for Chicago, 1981 to 2010
High °F Low °F   High °C Low °C
31 17 January -1 -9
35 20 February 2 -7
47 29 March 8 -2
59 39 April 15 4
70 48 May 21 9
80 58 June 27 15
84 64 July 29 18
82 63 August 28 17
75 54 September 24 12
62 43 October 17 6
48 32 November 9 0
35 21 December 2 -6
59 41 Year 15 5

Days of Hot Weather in Chicago

Temperatures don't normally reach 100 °F in Chicago. But it does get into the 90s on an average 14 days a year.

The days are above 50 degrees from June to September and nearly every day in May and October. But Chicago only gets that warm for a few days in winter.

Days per month in Chicago of at least 70, 80 or 90 °F
  70 °F
21 °C
80 °F
27 °C
90 °F
32 °C
January 0 0 0
February 0 0 0
March 2 0 0
April 6 2 0
May 15 6 1
June 26 16 3
July 30 23 6
August 30 19 4
September 21 9 1
October 7 2 0
November 1 0 0
December 0 0 0
Year 137 76 14

Freezing Temperatures in Chicago

Freezing temperatures can occur anytime from November to April in Chicago. Typically, for seven days each year the thermometer drops to zero degrees Fahrenheit (-18 °C) or colder.

The daytime temperature doesn't rise above freezing for 43 days annually, on average. November to March is when weather this cold can last all day.

Days in Chicago with temperature that drops to 10, 20, or 32 °F or lower
  10 °F
-12 °C
20 °F
-8 °C
32 °F
0 °C
January 9 17 28
February 6 13 24
March 1 5 20
April 0 0 6
May 0 0 0
June 0 0 0
July 0 0 0
August 0 0 0
September 0 0 0
October 0 0 4
November 0 3 14
December 6 13 26
Year 22 51 122
References

Jay Lawrimore, Ron Ray, Scott Applequist, Bryant Korzeniewski, Matthew Menne. 2016. Global Summary of the Month and Year, Version 1.0. NOAA National Centers for Environmental Information.

NOAA National Centers for Environmental Information. 1981-2010 U.S. Climate Normals. (Data Access. FTP.)

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