St. Louis, MO Climate & Monthly Averages
The climate of St. Louis
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.
Climate quick facts
- 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%
Temperatures through 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.
Rain, sun and snow
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).
How St. Louis compares
- 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.
Ranked against every city in our dataset, each measured on the same ten-year window.
Monthly climate table
| Month | High | Low | Rain days | Precipitation | Sunshine | Humidity |
|---|---|---|---|---|---|---|
| January | 41° | 25° | 9 | 3.2 in | 5.7 h/day | 69% |
| February | 46° | 27° | 8 | 2.7 in | 7.1 h/day | 66% |
| March | 57° | 38° | 13 | 5.5 in | 7.5 h/day | 67% |
| April | 66° | 46° | 11 | 5.0 in | 9.0 h/day | 65% |
| May | 76° | 58° | 14 | 5.4 in | 10.2 h/day | 71% |
| June | 86° | 67° | 11 | 4.5 in | 11.6 h/day | 68% |
| July | 88° | 71° | 13 | 6.9 in | 11.8 h/day | 73% |
| August | 85° | 69° | 13 | 5.4 in | 11.0 h/day | 74% |
| September | 82° | 63° | 8 | 4.7 in | 10.2 h/day | 69% |
| October | 69° | 51° | 9 | 3.6 in | 8.1 h/day | 67% |
| November | 55° | 38° | 9 | 3.3 in | 7.0 h/day | 69% |
| December | 47° | 31° | 8 | 3.2 in | 6.0 h/day | 71% |
St. Louis month by month
St. Louis weather in January
January brings highs around 41°F (5°C), lows near 25°F (-4°C), about 9 wet days and roughly 2 snowy days - typically the coldest month of the year in St. Louis.
St. Louis weather in February
February brings highs around 46°F (8°C), lows near 27°F (-3°C), about 8 wet days and roughly 3 snowy days - typically the driest month of the year in St. Louis.
St. Louis weather in March
March brings highs around 57°F (14°C), lows near 38°F (3°C), about 13 wet days.
St. Louis weather in April
April brings highs around 66°F (19°C), lows near 46°F (8°C), about 11 wet days.
St. Louis weather in May
May brings highs around 76°F (24°C), lows near 58°F (14°C), about 14 wet days.
St. Louis weather in June
June brings highs around 86°F (30°C), lows near 67°F (20°C), about 11 wet days.
St. Louis weather in July
July brings highs around 88°F (31°C), lows near 71°F (22°C), about 13 wet days - typically the hottest month and the wettest month and the sunniest month of the year in St. Louis.
St. Louis weather in August
August brings highs around 85°F (30°C), lows near 69°F (20°C), about 13 wet days.
St. Louis weather in September
September brings highs around 82°F (28°C), lows near 63°F (17°C), about 8 wet days.
St. Louis weather in October
October brings highs around 69°F (20°C), lows near 51°F (11°C), about 9 wet days.
St. Louis weather in November
November brings highs around 55°F (13°C), lows near 38°F (4°C), about 9 wet days.
St. Louis weather in December
December brings highs around 47°F (8°C), lows near 31°F (0°C), about 8 wet days and roughly 1 snowy days.
Seasons 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.
Climate questions, answered
How many rainy days does St. Louis get in a year?
How many hot months does St. Louis have?
How warm is St. Louis on average?
Is St. Louis cold in winter?
How much sun does St. Louis get?
What should I pack for 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.
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.
St. Louis temperature records (2015-2024)
Derived from ERA5 reanalysis data, 2015–2024. Official station records may differ.