St. Louis
September
Weather in St. Louis for September 2025
Your guide to St. Louis weather in September - trends and predictions
In general, the average temperature in St. Louis at the beginning of September is 30 °F. As the month progressed, temperatures tended to noticeably cool down, reaching an average of 27.3 °F by the end of September.
The climate of St. Louis in September is notably wet, with an average of 15 rainy days, and a total of 82.9 mm of precipitation.
New! Chat with our AI weatherman - it’s amazing and free.
Temperatures
Rain 🌧️
More
15
Dry days
15
Rainy days
0
Snow days
29°/16°
Temperatures
16 km/h
Avg max wind
59 %
Avg humidity
St. Louis in September average weather
Move between months or click on a day
| Mon. | Tue. | Wed. | Thu. | Fri. | Sat. | Sun. |
|---|---|---|---|---|---|---|
| 1  31° | 2 30° | 3  30° | 4  30° | 5  29° | 6  31° | 7 29° |
| 8 28° | 9 29° | 10 30° | 11 31° | 12 29° | 13 29° | 14 29° |
| 15 29° | 16 31° | 17  29° | 18 31° | 19 32° | 20 32° | 21 28° |
| 22 27° | 23 23° | 24 28° | 25 27° | 26 28° | 27 27° | 28 27° |
| 29  27° | 30 27° |
You can click on date
Access St. Louis weather forecasts with a simple click. Select any date for comprehensive insights on temperature, rainfall, and wind conditions.
Temperatures trend during September in St. Louis
See the weather trend as well as the moving average line
September weather day by day
Click on a date for more information
| Date | Weather | Temperatures | Rain | UV | More |
|---|---|---|---|---|---|
| Sept. 1 | Sunny | 31° /16° | 0.9 mm | 7 | |
| Sept. 2 | Sunny | 30° /16° | 0.1 mm | 7 | |
| Sept. 3 | Partly cloudy | 30° /17° | 3.6 mm | 7 | |
| Sept. 4 | Moderate or heavy rain shower | 30° /18° | 8.7 mm | 7 | |
| Sept. 5 | Overcast | 29° /19° | 1.2 mm | 7 | |
| Sept. 6 | Patchy rain possible | 31° /19° | 0.7 mm | 7 | |
| Sept. 7 | Sunny | 29° /16° | 0.2 mm | 7 | |
| Sept. 8 | Sunny | 28° /14° | 0.1 mm | 7 | |
| Sept. 9 | Sunny | 29° /13° | 0 mm | 7 | |
| Sept. 10 | Sunny | 30° /15° | 0.3 mm | 7 | |
| Sept. 11 | Sunny | 31° /17° | 4 mm | 7 | |
| Sept. 12 | Sunny | 29° /17° | 6.1 mm | 7 | |
| Sept. 13 | Sunny | 29° /15° | 1.4 mm | 7 | |
| Sept. 14 | Sunny | 29° /15° | 1.6 mm | 7 | |
| Sept. 15 | Overcast | 29° /16° | 0.7 mm | 7 | |
| Sept. 16 | Partly cloudy | 31° /17° | 0.1 mm | 8 | |
| Sept. 17 | Heavy rain at times | 29° /17° | 0.4 mm | 7 | |
| Sept. 18 | Sunny | 31° /17° | 0 mm | 7 | |
| Sept. 19 | Sunny | 32° /18° | 0.1 mm | 8 | |
| Sept. 20 | Patchy rain possible | 32° /19° | 1.9 mm | 7 | |
| Sept. 21 | Moderate or heavy rain shower | 28° /18° | 16.6 mm | 6 | |
| Sept. 22 | Sunny | 27° /16° | 19.3 mm | 7 | |
| Sept. 23 | Sunny | 23° /14° | 7.8 mm | 5 | |
| Sept. 24 | Sunny | 28° /15° | 4.2 mm | 6 | |
| Sept. 25 | Sunny | 27° /15° | 0.5 mm | 6 | |
| Sept. 26 | Sunny | 28° /14° | 0 mm | 7 | |
| Sept. 27 | Sunny | 27° /16° | 0.9 mm | 6 | |
| Sept. 28 | Sunny | 27° /15° | 1.3 mm | 7 | |
| Sept. 29 | Cloudy | 27° /15° | 0 mm | 7 | |
| Sept. 30 | Sunny | 27° /16° | 0.2 mm | 6 | |
| Next | |||||
Important Notice
Our weather forecast for St. Louis in September is based on the analysis of historical data rather than real-time forecast models. While this provides a general overview, weather conditions can change. We recommend that you check the St. Louis forecast closer to your planned date for the most up-to-date weather information.
St. Louis in September - FAQ
What are the expected maximum and minimum temperatures in St. Louis during September?
During September, expect a variety of temperatures with highs around 29° and lows near 16°, suitable for diverse activities and preferences.
How much rainfall should be expected in St. Louis during September?
Moderate rainfall is anticipated in St. Louis during September, with a total of 82.9 mm spread over approximately 15 days. Considering plans for rainy days is advisable.
What are the typical wind conditions in St. Louis during September?
The average wind speed in St. Louis during September is 16 km/h, suggesting breezy to windy conditions, depending on your activities.
September rainfall patterns in St. Louis
Explore the daily rainfall trends and prepare for St. Louiss September weather 💧
UV exposure in St. Louis during September
Stay informed about UV levels for safe outdoor activities throughout the month of September ☀️
Quick links
You are here
Where is St. Louis?Get accurate weather forecasts for St. Louis, located at latitude 38.627 and longitude -90.198. Stay updated with localized weather information tailored for St. Louis.
Related locations
Select a location for accurate weather forecast
More Locations Found a mistake?
We appreciate your attention to details. Tell us here.