Climate averages 1991–2020
St. Louis weather
in October.
A mild, moderately wet month: the 6th warmest and the 7th driest of the year.
Long-term climate patterns, not a forecast for a particular trip.
October is a mild month in St. Louis: daytime highs average 19.9°C and nights cool to about 10.3°C. By daytime temperature it is the 6th warmest of the 12 months.
Expect about 87 mm of rain on roughly 8 days, which makes October a moderately wet month (the 7th driest of the 12 months). Daylight, from sunrise to sunset, lasts about 11 h 14 min on an average October day.
The nearest other city in this atlas is O'Fallon (48 km away). In October its highs average 19.5°C, about as warm as St. Louis, with 84 mm of rain.
Among the 498 cities listed in the United States, St. Louis ranks joint 282nd of 498 for the warmest October highs and joint 327th of 498 for the driest October (rainfall, lowest first). The mean October high of those 498 cities is 21.4°C; St. Louis is 1.5°C cooler than that mean.
From October to November, average highs fall by 7.6°C to 12.3°C, and monthly rainfall rises from 87 mm to 93 mm.
The annual picture
October 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 | 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, selected | 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
October in nearby cities
- O'Fallon in OctoberUnited States · 48 kmHigh 19.5°C · Low 10.4°C · 84 mm rain
- Springfield (Illinois), United States in OctoberUnited States · 139 kmHigh 18.4°C · Low 9.2°C · 83 mm rain
- Decatur in OctoberUnited States · 172 kmHigh 18.2°C · Low 9.1°C · 88 mm rain
- Columbia (Missouri), United States in OctoberUnited States · 189 kmHigh 19.2°C · Low 10.1°C · 83 mm rain
- Bloomington (Illinois), United States in OctoberUnited States · 231 kmHigh 17.4°C · Low 8.5°C · 85 mm rain
- Peoria (Illinois), United States in OctoberUnited States · 236 kmHigh 17.5°C · Low 8.9°C · 79 mm rain
- Champaign in OctoberUnited States · 236 kmHigh 17.9°C · Low 8.7°C · 84 mm rain
- Evansville in OctoberUnited States · 242 kmHigh 20.2°C · Low 11.2°C · 90 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.