St Louis MO Average Temperatures 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

St Louis Temperatures: Averages by Month

Days of Hot Weather in St Louis

How Often St Louis Has Cold Temperatures

References

More on Weather in Missouri