Climate averages 1991–2020
St. Louis weather
in July.
A hot, moderately wet month: the warmest and the 6th driest of the year.
Long-term climate patterns, not a forecast for a particular trip.
July is a hot month in St. Louis: daytime highs average 31.0°C and nights cool to about 21.6°C. By daytime temperature it is the warmest month of the year.
Expect about 86 mm of rain on roughly 10 days, which makes July a moderately wet month (the 6th driest of the 12 months). Daylight, from sunrise to sunset, lasts about 14 h 35 min on an average July day.
The nearest other city in this atlas is O'Fallon (48 km away). In July its highs average 30.8°C, about as warm as St. Louis, with 82 mm of rain.
Among the 498 cities listed in the United States, St. Louis ranks joint 194th of 498 for the warmest July highs and joint 281st of 498 for the driest July (rainfall, lowest first). The mean July high of those 498 cities is 30.3°C; St. Louis is 0.7°C warmer than that mean.
From July to August, average highs fall by 0.6°C to 30.4°C, and monthly rainfall falls from 86 mm to 74 mm.
The annual picture
July in context
Monthly rainfall
Average total · mmAverages from hourly ERA5 reanalysis data. Actual weather varies from year to year. How these numbers are calculated
Every month, side by side
St. Louis climate table
| Month | Average highHigh / low | Average low | Rainfall mm/month | Rain days ≥1 mm/day | Daylight hours/dayDaylight h/day |
|---|---|---|---|---|---|
| January | 4.3°C-4.3°C | -4.3°C | 70 | 8.2 | 9.810 h |
| February | 7.2°C-2.5°C | -2.5°C | 63 | 7.8 | 10.711 h |
| March | 13.0°C2.6°C | 2.6°C | 94 | 10.5 | 11.912 h |
| April | 19.1°C8.4°C | 8.4°C | 117 | 11.2 | 13.213 h |
| May | 24.3°C14.3°C | 14.3°C | 128 | 13.4 | 14.314 h |
| June | 29.1°C19.3°C | 19.3°C | 106 | 11.0 | 14.815 h |
| July, selected | 31.0°C21.6°C | 21.6°C | 86 | 9.9 | 14.615 h |
| August | 30.4°C20.9°C | 20.9°C | 74 | 9.1 | 13.714 h |
| September | 26.4°C16.6°C | 16.6°C | 83 | 7.6 | 12.512 h |
| October | 19.9°C10.3°C | 10.3°C | 87 | 8.4 | 11.211 h |
| November | 12.3°C3.6°C | 3.6°C | 93 | 8.6 | 10.110 h |
| December | 6.3°C-1.7°C | -1.7°C | 65 | 8.2 | 9.510 h |
Rainfall is the average of the 30 separate monthly totals. A rain day is a local calendar day with at least 1 mm of precipitation. Daylight is the calculated sunrise-to-sunset length, not measured sunshine.
Compare places
July in nearby cities
- O'Fallon in JulyUnited States · 48 kmHigh 30.8°C · Low 21.6°C · 82 mm rain
- Springfield (Illinois), United States in JulyUnited States · 139 kmHigh 29.1°C · Low 20.2°C · 91 mm rain
- Decatur in JulyUnited States · 172 kmHigh 28.8°C · Low 19.9°C · 91 mm rain
- Columbia (Missouri), United States in JulyUnited States · 189 kmHigh 31.1°C · Low 21.6°C · 93 mm rain
- Bloomington (Illinois), United States in JulyUnited States · 231 kmHigh 28.2°C · Low 19.3°C · 98 mm rain
- Peoria (Illinois), United States in JulyUnited States · 236 kmHigh 28.8°C · Low 20.1°C · 96 mm rain
- Champaign in JulyUnited States · 236 kmHigh 28.3°C · Low 19.3°C · 92 mm rain
- Evansville in JulyUnited States · 242 kmHigh 30.8°C · Low 22.0°C · 86 mm rain
Read the numbers correctly
Climate, not a promise.
These patterns help compare months. They cannot tell you the weather on a specific day of your trip.
Sources, method and limitsHow these numbers are made (what the highs, lows and rain days mean, the sources and the model cell used for St. Louis) is explained once on the St. Louis year overview and on the Sources, method and limits page.