Weather in Rapid City, South Dakota for September 2026
Until now, September 2026 in Rapid City has been nearly identical to the historical average, with a temperature of 26.5 °F (showing only a slight deviation of 0.3 °F).
The forecast for the next days in Rapid City predicts temperatures to be around 24 °F, close to the historical average.
In general, the average temperature in Rapid City at the beginning of September is 29.6 °F. As the month progressed, temperatures tended to significantly cool down, reaching an average of 24.4 °F by the end of September.
Rapid City experiences moderate rainfall in September, with an average of 7 rainy days and a total precipitation of 116.4 mm.
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Rapid City Weather September
Temperatures trend during September in Rapid City
September weather in Rapid City day by day
| Date | Weather | Temperatures | Rain | UV | More |
|---|---|---|---|---|---|
| Sept. 1 |  Sunny | 28° /15° | 1.3 mm | 5 | |
| Sept. 2 | Sunny | 33° /16° | 0 mm | 8 | |
| Sept. 3 |  Overcast | 32° /18° | 0 mm | 7 | |
| Sept. 4 |  Heavy rain at times | 30° /16° | 0.5 mm | 6 | |
| Sept. 5 | Sunny | 27° /14° | 0.1 mm | 7 | |
| Sept. 6 | Sunny | 27° /12° | 0 mm | 6 | |
| Sept. 7 | Sunny | 30° /13° | 3.2 mm | 6 | |
| Sept. 8 | Sunny | 30° /16° | 0 mm | 7 | |
| Sept. 9 |  Cloudy | 31° /16° | 1.4 mm | 7 | |
| Sept. 10 | Sunny | 33° /16° | 0 mm | 8 | |
| Sept. 11 |  Partly cloudy | 31° /17° | 0 mm | 7 | |
| Sept. 12 |  Moderate or heavy rain shower | 28° /15° | 1.3 mm | 6 | |
| Sept. 13 | Moderate rain at times | 24° /13° | 5.1 mm | 6 | |
| Sept. 14 | Overcast | 25° /13° | 12.1 mm | 5 | |
| Sept. 15 | Partly cloudy | 27° /12° | 0 mm | 7 | |
| Sept. 16 | Partly cloudy | 28° /14° | 0 mm | 5 | |
| Sept. 17 | Moderate or heavy rain shower | 22° /14° | 31.4 mm | 4 | |
| Sept. 18 | Sunny | 23° /13° | 30.6 mm | 5 | |
| Sept. 19 | Sunny | 22° /13° | 1.6 mm | 4 | |
| Sept. 20 | Sunny | 23° /12° | 7.3 mm | 5 | |
| Sept. 21 | Sunny | 20° /11° | 2.1 mm | 4 | |
| Sept. 22 | Sunny | 22° /11° | 0.3 mm | 6 | |
| Sept. 23 | Overcast | 23° /11° | 0.2 mm | 4 | |
| Sept. 24 | Sunny | 25° /13° | 0 mm | 6 | |
| Sept. 25 | Sunny | 27° /13° | 0 mm | 6 | |
| Sept. 26 | Sunny | 24° /14° | 0 mm | 5.1 | |
| Sept. 27 | Partly cloudy | 21° /12° | 2.7 mm | 4.5 | |
| Sept. 28 | Overcast | 27° /16° | 0.2 mm | 4.7 | |
| Sept. 29 | Overcast | 23° /14° | 0 mm | 4.8 | |
| Sept. 30 | Sunny | 24° /15° | 0 mm | 5.2 | |
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Rapid City in September - FAQ
What are the expected maximum and minimum temperatures in Rapid City during September?
How much rainfall should be expected in Rapid City during September?
What are the typical wind conditions in Rapid City during September?
September rainfall patterns in Rapid City
UV exposure in Rapid City during September
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Where is Rapid City?Get accurate weather forecasts for Rapid City, located at latitude 44.081 and longitude -103.231. Stay updated with localized weather information tailored for Rapid City.