Pennington County (Rapid City)
September
Weather in Pennington County, South Dakota for September 2025
Your guide to Pennington County weather in September - trends and predictions
Until now, September 2025 in Pennington County is cooler than usual, with temperatures averaging 26.5 °F, this is -2.3 °F below the typical seasonal average.
The forecast for the next days in Pennington County predicts a temperature of 22.8 °F, which is cooler than the historical average.
In general, the average temperature in Pennington County at the beginning of September is 27.4 °F. As the month progressed, temperatures tended to noticeably cool down, reaching an average of 25.1 °F by the end of September.
With an average of 4 rainy days, Pennington County experiences minimal rainfall in September.
New! Chat with our AI weatherman - it’s amazing and free.
Temperatures
Rain 🌧️
More
26
Dry days
4
Rainy days
0
Snow days
29°/15°
Temperatures
26 km/h
Avg max wind
34 %
Avg humidity
Pennington County Weather September
Move between months or click on a day
Temperatures trend during September in Pennington County
See the weather trend as well as the moving average line
September weather in Pennington County day by day
Click on a date for more information
| Date | Weather | Temperatures | Rain | UV | More |
|---|---|---|---|---|---|
| Sept. 1 |  Sunny | 29° /15° | 0 mm | 7 | |
| Sept. 2 | Sunny | 33° /18° | 0 mm | 9 | |
| Sept. 3 |  Overcast | 29° /17° | 0 mm | 7 | |
| Sept. 4 |  Heavy rain at times | 27° /16° | 0.6 mm | 7 | |
| Sept. 5 |  Partly cloudy | 23° /11° | 0 mm | 7 | |
| Sept. 6 | Sunny | 23° /9° | 0 mm | 6 | |
| Sept. 7 | Sunny | 28° /11° | 0 mm | 7 | |
| Sept. 8 | Sunny | 31° /17° | 0 mm | 7 | |
| Sept. 9 |  Cloudy | 32° /18° | 2.2 mm | 7 | |
| Sept. 10 | Partly cloudy | 32° /17° | 0 mm | 8 | |
| Sept. 11 | Partly cloudy | 32° /17° | 0 mm | 8 | |
| Sept. 12 |  Moderate or heavy rain shower | 31° /18° | 1.8 mm | 7 | |
| Sept. 13 | Moderate rain at times | 24° /15° | 6.4 mm | 6 | |
| Sept. 14 | Overcast | 24° /13° | 17.8 mm | 5 | |
| Sept. 15 | Partly cloudy | 30° /15° | 0 mm | 1.3 | |
| Sept. 16 | Cloudy | 22° /15° | 0 mm | 1.1 | |
| Sept. 17 |  Heavy rain | 17° /13° | 102.9 mm | 0.5 | |
| Sept. 18 | Heavy rain | 21° /13° | 86.6 mm | 1 | |
| Sept. 19 |  Patchy rain possible | 18° /12° | 2.4 mm | 0 | |
| Sept. 20 | Sunny | 24° /11° | 0 mm | 5 | |
| Sept. 21 | Partly cloudy | 25° /15° | 0.1 mm | 5 | |
| Sept. 22 | Sunny | 23° /14° | 0 mm | 5 | |
| Sept. 23 | Sunny | 22° /10° | 0 mm | 5 | |
| Sept. 24 | Sunny | 27° /12° | 0 mm | 5 | |
| Sept. 25 | Sunny | 32° /16° | 0 mm | 6 | |
| Sept. 26 | Patchy rain possible | 22° /14° | 0.6 mm | 4 | |
| Sept. 27 | Patchy rain possible | 15° /9° | 3.5 mm | 3 | |
| Sept. 28 | Sunny | 21° /7° | 0 mm | 4 | |
| Sept. 29 | Sunny | 35° /22° | 0 mm | 9 | |
| Sept. 30 | Sunny | 24° /10° | 0 mm | 6 | |
| Next | |||||
Important Notice
Our weather forecast for Pennington 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 Pennington County forecast closer to your planned date for the most up-to-date weather information.
Change Month
Pennington County in September - FAQ
What are the expected maximum and minimum temperatures in Pennington County during September?
During September, expect a variety of temperatures with highs around 29° and lows near 15°, suitable for diverse activities and preferences.
How much rainfall should be expected in Pennington County during September?
Expect minimal rainfall in Pennington County during September, with a total of 16.2 mm over approximately 4 days. This minimal precipitation is unlikely to significantly impact plans.
What are the typical wind conditions in Pennington County during September?
The average wind speed in Pennington County during September is 26 km/h, suggesting breezy to windy conditions, depending on your activities.
September rainfall patterns in Pennington County
Explore the daily rainfall trends and prepare for Pennington Countys September weather 💧
UV exposure in Pennington County during September
Stay informed about UV levels for safe outdoor activities throughout the month of September ☀️
Top locations in Pennington County
Select a location for an accurate weather forecast
More Locations Quick links
More Pennington County weather pages
You are here
Where is Pennington County?Get accurate weather forecasts for Pennington County, located at latitude 44.081 and longitude -103.231. Stay updated with localized weather information tailored for Pennington County.
Found a mistake?
We appreciate your attention to details. Tell us here.