St. Louis, MO Climate & Monthly Averages
St. Louis has a humid subtropical climate. July is the hottest month, averaging 88° by day; January is the coldest at 41°.
St. Louis's climate is a story of contrasts
St. Louis runs one of the wider annual swings in our dataset: 26°C separates the average July from the average January. Afternoons reach 88°F (31°C) at the peak of summer and 41°F (5°C) at the depth of winter, with 126 days of measurable precipitation through the year.
July
88° by day 71° at nightJanuary
41° by day 25° at nightThe two ends of the year
The wettest month is July (6.9 inches (174 mm) across 13 days) and the driest February. At its warmest, in July, St. Louis runs to 88°F (31°C) in the afternoon and back to 71°F (22°C) by dawn. January is the coolest month, with highs of 41°F (5°C) and lows near 25°F (-4°C). Snow falls on roughly 8 days a year, mostly November through March.
Overnight lows average at or below freezing for 3 months, December through February. Between the average July and the average January lie 26°C, a wider spread than roughly 86% of the cities we track. July is the brightest month at 11.8 hours of sun a day, against an annual average of 8.8. Across the gridded 2015-2024 daily record, the highest daily maximum for this location was 104°F (40°C) and the lowest daily minimum -7°F (-22°C).
More climate facts for St. Louis
- Hottest month: July - highs near 88°F (31°C)
- Coldest month: January - highs near 41°F (5°C)
- Decade extremes (2015-2024): 104°F (40°C) high · -7°F (-22°C) low
- Wettest month: July (13 rainy days) · Sunniest: July (11.8 h sun/day)
- Climate type: humid subtropical
- Annual swing: 26°C between the average warmest and coolest month · day to night: 10°C
- Snow: about 8 days a year
- Months averaging 30°C or hotter: 2
- Average humidity: 69%
Four distinct parts of the year in St. Louis
Spring (March through May)
Spring in St. Louis is mild, with daytime highs averaging 66°F (19°C) and nights around 47°F (8°C); rain falls on around 39 of the 90 days.
Summer (June through August)
Summer is hot here - highs near 86°F (30°C), nights near 69°F (20°C), and rain falls on around 37 of the 90 days. Daylight is generous - around 11.5 hours of sun a day. With the moisture factored in, afternoons feel hotter than the reading suggests - the humidity and dew point converter shows why.
Fall (September through November)
Through fall, St. Louis brings comfortable warmth: 69°F (20°C) by day, 51°F (10°C) after dark, and expect showers on roughly 26 days across the season.
Winter (December through February)
Winter in St. Louis stays firmly cold, with daytime highs averaging 45°F (7°C) and nights around 28°F (-2°C); expect showers on roughly 25 days across the season, plus about 6 snowy days.
St. Louis temperature extremes in the 2015–2024 dataset
Derived from ERA5 reanalysis data, 2015–2024. Official station records may differ. Need another precipitation unit? Use the rainfall converter.
Choosing a season in St. Louis
Best time to visit St. Louis
Aim for September to November and April if you get the choice: warm days, manageable rainfall and plenty of daylight line up, and highs average 68°F (20°C) against roughly 9 wet days a month. For the same question asked the other way round, see where else is warm in September.
What to pack
Pack for St. Louis with light clothing for the warm months, a heavy insulated coat, hat and gloves for winter and a compact umbrella or rain shell. Even in July, lows of 71°F (22°C) make an extra layer worth the space.
Monthly highs, lows and seasonal change
| Month | High | Low | Rain days | Precipitation | Sunshine | Daylight | Wet-day chance | Humidity |
|---|---|---|---|---|---|---|---|---|
| January | 41° | 25° | 9 | 3.2 in | 5.7 h/day | 9.7 h | 28% | 69% |
| February | 46° | 27° | 8 | 2.7 in | 7.1 h/day | 10.7 h | 30% | 66% |
| March | 57° | 38° | 13 | 5.5 in | 7.5 h/day | 11.8 h | 41% | 67% |
| April | 66° | 46° | 11 | 5.0 in | 9.0 h/day | 13.2 h | 38% | 65% |
| May | 76° | 58° | 14 | 5.4 in | 10.2 h/day | 14.3 h | 46% | 71% |
| June | 86° | 67° | 11 | 4.5 in | 11.6 h/day | 14.8 h | 36% | 68% |
| July | 88° | 71° | 13 | 6.9 in | 11.8 h/day | 14.6 h | 43% | 73% |
| August | 85° | 69° | 13 | 5.4 in | 11.0 h/day | 13.7 h | 41% | 74% |
| September | 82° | 63° | 8 | 4.7 in | 10.2 h/day | 12.4 h | 27% | 69% |
| October | 69° | 51° | 9 | 3.6 in | 8.1 h/day | 11.1 h | 28% | 67% |
| November | 55° | 38° | 9 | 3.3 in | 7.0 h/day | 10.0 h | 30% | 69% |
| December | 47° | 31° | 8 | 3.2 in | 6.0 h/day | 9.5 h | 25% | 71% |
St. Louis from the coldest month to the hottest
Each card shows the average high and low. The bar places that month between St. Louis's coldest night and warmest afternoon.
January
- Rain
- 9 days
- Sunshine
- 5.7 h
- Daylight
- 9.7 h
- Snow
- 2 days
February
- Rain
- 8 days
- Sunshine
- 7.1 h
- Daylight
- 10.7 h
- Snow
- 3 days
March
- Rain
- 13 days
- Sunshine
- 7.5 h
- Daylight
- 11.8 h
April
- Rain
- 11 days
- Sunshine
- 9.0 h
- Daylight
- 13.2 h
May
- Rain
- 14 days
- Sunshine
- 10.2 h
- Daylight
- 14.3 h
June
- Rain
- 11 days
- Sunshine
- 11.6 h
- Daylight
- 14.8 h
July
- Rain
- 13 days
- Sunshine
- 11.8 h
- Daylight
- 14.6 h
August
- Rain
- 13 days
- Sunshine
- 11.0 h
- Daylight
- 13.7 h
September
- Rain
- 8 days
- Sunshine
- 10.2 h
- Daylight
- 12.4 h
October
- Rain
- 9 days
- Sunshine
- 8.1 h
- Daylight
- 11.1 h
November
- Rain
- 9 days
- Sunshine
- 7.0 h
- Daylight
- 10.0 h
December
- Rain
- 8 days
- Sunshine
- 6.0 h
- Daylight
- 9.5 h
- Snow
- 1 day
Looking for warmer alternatives? Browse warm places by month, or compare St. Louis's coolest part of the year: January, February, December.
Where St. Louis sits among other climates
- St. Louis sits close to the middle of our dataset on most measures: 57°F (14°C) as an annual average, 53.4 inches (1357 mm) of precipitation and 8.8 hours of sun a day.
These comparisons use the same ten-year window for every city in the dataset.