Bismarck (ND)
September
Weather in Bismarck, North Dakota for September 2026
Your guide to Bismarck weather in September - trends and predictions
In general, the average temperature in Bismarck at the beginning of September is 20 °F. As the month progressed, temperatures tended to significantly warm up, reaching an average of 25.6 °F by the end of September.
Bismarck experiences moderate rainfall in September, with an average of 8 rainy days and a total precipitation of 306.6 mm.
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Temperatures
Rain 🌧️
More
22
Dry days
8
Rainy days
0
Snow days
23°/13°
Temperatures
20 km/h
Avg max wind
70 %
Avg humidity
Bismarck Weather September
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Temperatures trend during September in Bismarck
See the weather trend as well as the moving average line
September weather in Bismarck day by day
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| Date | Weather | Temperatures | Rain | UV | More |
|---|---|---|---|---|---|
| Sept. 1 |  Partly cloudy | 27° /15° | 0 mm | 7 | |
| Sept. 2 |  Heavy rain at times | 27° /16° | 5.5 mm | 7 | |
| Sept. 3 |  Overcast | 17° /12° | 0 mm | 5 | |
| Sept. 4 |  Light rain shower | 18° /8° | 3.7 mm | 5 | |
| Sept. 5 | Overcast | 13° /9° | 0 mm | 5 | |
| Sept. 6 | Overcast | 16° /7° | 0 mm | 5 | |
| Sept. 7 |  Sunny | 22° /5° | 0 mm | 6 | |
| Sept. 8 | Sunny | 28° /10° | 0 mm | 6 | |
| Sept. 9 | Sunny | 28° /12° | 0 mm | 6 | |
| Sept. 10 | Sunny | 28° /14° | 0 mm | 5 | |
| Sept. 11 |  Thundery outbreaks possible | 27° /17° | 0 mm | 5 | |
| Sept. 12 |  Fog | 26° /19° | 0 mm | 5 | |
| Sept. 13 |  Moderate or heavy rain shower | 21° /17° | 75.8 mm | 1 | |
| Sept. 14 | Light rain shower | 25° /18° | 14 mm | 1 | |
| Sept. 15 |  Moderate or heavy rain with thunder | 26° /15° | 43.4 mm | 3 | |
| Sept. 16 | Fog | 28° /15° | 0 mm | 5 | |
| Sept. 17 | Light rain shower | 22° /17° | 6 mm | 1 | |
| Sept. 18 |  Heavy rain | 13° /12° | 155.6 mm | 1 | |
| Sept. 19 |  Light rain | 14° /12° | 2.6 mm | 1 | |
| Sept. 20 | Mist | 19° /13° | 0 mm | 2 | |
| Sept. 21 | Mist | 24° /12° | 0 mm | 4 | |
| Sept. 22 | Sunny | 26° /12° | 0 mm | 4 | |
| Sept. 23 | Sunny | 23° /12° | 0 mm | 4 | |
| Sept. 24 | Sunny | 25° /11° | 0 mm | 4 | |
| Sept. 25 | Sunny | 25° /13° | 0 mm | 4 | |
| Sept. 26 | Sunny | 27° /10° | 0 mm | 4 | |
| Sept. 27 | Sunny | 22° /9° | 0 mm | 3 | |
| Sept. 28 | Sunny | 25° /10° | 0 mm | 3 | |
| Sept. 29 | Thundery outbreaks possible | 28° /16° | 0 mm | 3 | |
| Sept. 30 | Thundery outbreaks possible | 27° /19° | 0 mm | 3 | |
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Important Notice
Our weather forecast for Bismarck 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 Bismarck forecast closer to your planned date for the most up-to-date weather information.
Change Month
Bismarck in September - FAQ
What are the expected maximum and minimum temperatures in Bismarck during September?
Enjoy moderate daytime temperatures of up to 23° and cooler nights around 13°. Ideal for a range of outdoor activities, from hiking to city tours.
How much rainfall should be expected in Bismarck during September?
Significant rainfall exceeding 306.6 mm is expected in Bismarck during September, occurring over more than 8 days. Preparing for wet conditions is recommended in your planning.
What are the typical wind conditions in Bismarck during September?
The average wind speed in Bismarck during September is 20 km/h, suggesting breezy to windy conditions, depending on your activities.
September rainfall patterns in Bismarck
Explore the daily rainfall trends and prepare for Bismarcks September weather 💧
Typically, Bismarck has 8 rainy days in September with a total of 306.6 mm of rainfall.
UV exposure in Bismarck during September
Stay informed about UV levels for safe outdoor activities throughout the month of September ☀️
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