Saint Louis County (Eureka)
September
Weather in Saint Louis County, Missouri for September 2026
Your guide to Saint Louis County weather in September - trends and predictions
In general, the average temperature in Saint Louis County at the beginning of September is 26.6 °F. As the month progressed, temperatures tended to moderately fall, reaching an average of 25.7 °F by the end of September.
Saint Louis County experiences moderate rainfall in September, with an average of 6 rainy days and a total precipitation of 110.8 mm.
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Temperatures
Rain 🌧️
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24
Dry days
6
Rainy days
0
Snow days
27°/16°
Temperatures
13 km/h
Avg max wind
64 %
Avg humidity
Saint Louis County Weather September
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Temperatures trend during September in Saint Louis County
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September weather in Saint Louis County day by day
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| Date | Weather | Temperatures | Rain | UV | More |
|---|---|---|---|---|---|
| Sept. 1 |  Fog | 29° /18° | 0 mm | 7 | |
| Sept. 2 |  Sunny | 29° /17° | 0 mm | 7 | |
| Sept. 3 |  Overcast | 26° /15° | 0 mm | 6 | |
| Sept. 4 | Sunny | 27° /15° | 7.2 mm | 7 | |
| Sept. 5 |  Partly cloudy | 26° /15° | 0 mm | 7 | |
| Sept. 6 |  Patchy rain possible | 26° /15° | 14.1 mm | 6 | |
| Sept. 7 | Sunny | 23° /11° | 0 mm | 6 | |
| Sept. 8 | Sunny | 25° /9° | 0 mm | 7 | |
| Sept. 9 | Sunny | 26° /11° | 0 mm | 6 | |
| Sept. 10 | Sunny | 30° /14° | 0 mm | 8 | |
| Sept. 11 | Partly cloudy | 33° /18° | 0 mm | 8 | |
| Sept. 12 | Sunny | 31° /19° | 0 mm | 8 | |
| Sept. 13 | Patchy rain possible | 30° /20° | 2.2 mm | 7 | |
| Sept. 14 | Mist | 31° /20° | 0 mm | 7 | |
| Sept. 15 | Light rain shower | 29° /20° | 1.8 mm | 7 | |
| Sept. 16 | Partly cloudy | 32° /20° | 0 mm | 8 | |
| Sept. 17 |  Cloudy | 30° /19° | 0 mm | 7 | |
| Sept. 18 | Sunny | 32° /18° | 0 mm | 8 | |
| Sept. 19 | Sunny | 32° /19° | 1.9 mm | 8 | |
| Sept. 20 |  Moderate rain at times | 32° /21° | 15.5 mm | 7 | |
| Sept. 21 |  Thundery outbreaks possible | 26° /21° | 46.2 mm | 6 | |
| Sept. 22 | Moderate or heavy rain shower | 29° /18° | 17.8 mm | 7 | |
| Sept. 23 | Moderate or heavy rain shower | 22° /16° | 46.5 mm | 5 | |
| Sept. 24 | Moderate or heavy rain shower | 22° /18° | 170.5 mm | 5 | |
| Sept. 25 | Fog | 24° /14° | 0 mm | 5 | |
| Sept. 26 | Fog | 26° /13° | 0 mm | 6 | |
| Sept. 27 | Overcast | 26° /16° | 0 mm | 6 | |
| Sept. 28 | Overcast | 27° /16° | 0.9 mm | 7 | |
| Sept. 29 | Overcast | 27° /18° | 0 mm | 7 | |
| Sept. 30 | Mist | 28° /18° | 0 mm | 7 | |
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Important Notice
Our weather forecast for Saint Louis County 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 Saint Louis County forecast closer to your planned date for the most up-to-date weather information.
Change Month
Saint Louis County in September - FAQ
What are the expected maximum and minimum temperatures in Saint Louis County during September?
During September, expect a variety of temperatures with highs around 27° and lows near 16°, suitable for diverse activities and preferences.
How much rainfall should be expected in Saint Louis County during September?
Significant rainfall exceeding 110.8 mm is expected in Saint Louis County during September, occurring over more than 6 days. Preparing for wet conditions is recommended in your planning.
What are the typical wind conditions in Saint Louis County during September?
The average wind speed in Saint Louis County during September is 13 km/h, suggesting breezy to windy conditions, depending on your activities.
September rainfall patterns in Saint Louis County
Explore the daily rainfall trends and prepare for Saint Louis Countys September weather 💧
UV exposure in Saint Louis County during September
Stay informed about UV levels for safe outdoor activities throughout the month of September ☀️
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Where is Saint Louis County?Get accurate weather forecasts for Saint Louis County, located at latitude 38.503 and longitude -90.628. Stay updated with localized weather information tailored for Saint Louis County.
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