St Louis Temperatures: Averages by Month

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

The average high and low temperatures are listed below monthly and annually for the city, 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 St Louis, scroll down farther. There are also monthly and yearly counts of days with cold weather.

The first set of high and low temperatures are averages for 2010 to 2019. Everything else here is based on 1991 to 2020 weather.

10-year temperature averages for St Louis, 2010 to 2019
High °F Low °F   High °C Low °C
41 24 January 5 -5
45 27 February 7 -3
57 38 March 14 3
69 48 April 21 9
79 60 May 26 15
88 69 June 31 21
91 73 July 33 23
89 70 August 32 21
83 63 September 28 17
70 50 October 21 10
56 37 November 13 3
46 30 December 8 -1
68 49 Year 20 9
30-year temperature averages for St Louis, 1991 to 2020
High °F Low °F   High °C Low °C
40 24 January 5 -5
46 28 February 8 -2
57 37 March 14 3
68 47 April 20 8
77 58 May 25 14
86 67 June 30 20
90 71 July 32 22
88 69 August 31 21
81 61 September 27 16
69 49 October 21 10
56 37 November 13 3
45 29 December 7 -2
67 48 Year 19 9

Days of Hot Weather in St Louis

On its hottest days, St Louis has temperatures in the 100s Fahrenheit (over 37 °C). Three days a year on average get that sweltering. One-hundred degree weather can show up anytime during the summer months.

Temperatures in the 90s F commonly occur here throughout summer. Highs of 90 degrees or more are possible from April to October.

Days per month in St Louis 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 2 0 0
March 6 1 0
April 14 5 0
May 24 14 2
June 29 25 11
July 31 29 16
August 31 29 13
September 27 17 5
October 16 6 0
November 4 0 0
December 1 0 0
Year 184 126 47

How Often St Louis Has Cold Temperatures

The coldest night of the year at St Louis typically drops down to 0 °F (-18 °C) or lower. But just one nights a winter on average gets that brisk.

The city normally has 19 days a year when it never warms up to above freezing. Frosty days can happen from November to March, but are most common in January.

Days per month on average in St Louis when the minimum temperature drops to 10, 20, or 32 °F or below
  10 °F
-12 °C
20 °F
-8 °C
32 °F
0 °C
January 4 11 24
February 1 7 19
March 0 2 10
April 0 0 1
May 0 0 0
June 0 0 0
July 0 0 0
August 0 0 0
September 0 0 0
October 0 0 1
November 0 1 9
December 1 6 20
Year 7 26 85
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 (NCEI). Climate Normals.

Missouri Temperatures
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