Climate
St. Louis weather by month
Average highs, lows, rain and snow for every month, from 30 years of weather records.
Average temperatures
- Jan
- Feb
- Mar
- Apr
- May
- Jun
- Jul
- Aug
- Sep
- Oct
- Nov
- Dec
Best time to visit: April, September, October, when highs are mild and rain is lightest.
Month by month
| Month | High | Low | Rain | Wet days |
|---|---|---|---|---|
| January | 40°F | 24°F | 2.5 in | 8 |
| February | 46°F | 28°F | 2.0 in | 8 |
| March | 56°F | 36°F | 3.3 in | 11 |
| April | 68°F | 46°F | 4.5 in | 11 |
| May | 77°F | 57°F | 4.8 in | 14 |
| June | 86°F | 65°F | 4.4 in | 11 |
| July | 89°F | 69°F | 3.7 in | 10 |
| August | 88°F | 66°F | 3.7 in | 10 |
| September | 81°F | 57°F | 3.4 in | 9 |
| October | 69°F | 46°F | 3.1 in | 9 |
| November | 55°F | 36°F | 3.3 in | 9 |
| December | 44°F | 29°F | 2.3 in | 8 |
NOAA U.S. Climate Normals 1991–2020, Cahokia St Louis Ap, Il Us (4.4 mi away, 413 ft). Wet days: days with at least 0.01 in of precipitation.
Questions
What is the hottest month in St. Louis?
July, with an average high of 89°F and low of 69°F.
What is the coldest month in St. Louis?
January, with an average low of 24°F and high of 40°F.
When does it rain most in St. Louis?
May is the wettest month, averaging 4.8 in of precipitation; the year totals about 41.0 inches.
What is the best time to visit St. Louis?
For mild weather (highs between 65°F and 85°F) with the least rain, April, September, October.
Where do these numbers come from?
NOAA’s 1991–2020 U.S. Climate Normals for the Cahokia St Louis Ap weather station, 4.4 miles from downtown: 30-year averages, not a forecast.