Bismarck (ND)
September
Weather in Bismarck, North Dakota for September 2026
Your guide to Bismarck weather in September - trends and predictions
So far, September 2026 in Bismarck is slightly warmer than the historical average by 0.8 °F.
The forecast for the next days in Bismarck predicts temperatures to be around 20 °F, close to the historical average.
In general, the average temperature in Bismarck at the beginning of September is 25.4 °F. As the month progressed, temperatures tended to noticeably cool down, reaching an average of 22.7 °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.
New! Chat with our AI weatherman - it’s amazing and free.
Temperatures
Rain 🌧️
More
22
Dry days
8
Rainy days
0
Snow days
23°/13°
Temperatures
20 km/h
Avg max wind
69 %
Avg humidity
Bismarck Weather September
Move between months or click on a day
Temperatures trend during September in Bismarck
See the weather trend as well as the moving average line
September weather in Bismarck day by day
Click on a date for more information
| Date | Weather | Temperatures | Rain | UV | More |
|---|---|---|---|---|---|
| Sept. 1 |  Partly cloudy | 27° /12° | 0 mm | 5 | |
| Sept. 2 |  Heavy rain at times | 28° /14° | 2.8 mm | 7 | |
| Sept. 3 |  Overcast | 23° /14° | 0.1 mm | 4 | |
| Sept. 4 |  Light rain shower | 25° /11° | 1.9 mm | 6 | |
| Sept. 5 | Overcast | 24° /14° | 0 mm | 6 | |
| Sept. 6 | Overcast | 26° /12° | 0 mm | 6 | |
| Sept. 7 |  Sunny | 25° /11° | 0.3 mm | 4 | |
| Sept. 8 | Sunny | 27° /12° | 0 mm | 6 | |
| Sept. 9 | Sunny | 26° /12° | 0 mm | 6 | |
| Sept. 10 | Sunny | 29° /11° | 0 mm | 5 | |
| Sept. 11 |  Thundery outbreaks possible | 25° /14° | 0 mm | 4 | |
| Sept. 12 |  Fog | 22° /13° | 0 mm | 4 | |
| Sept. 13 |  Moderate or heavy rain shower | 20° /13° | 37.9 mm | 3 | |
| Sept. 14 | Light rain shower | 23° /15° | 8.5 mm | 2 | |
| Sept. 15 |  Moderate or heavy rain with thunder | 22° /12° | 21.7 mm | 4 | |
| Sept. 16 | Fog | 24° /12° | 1.6 mm | 5 | |
| Sept. 17 | Light rain shower | 22° /13° | 3 mm | 2 | |
| Sept. 18 | Overcast | 18° /13° | 0 mm | 3 | |
| Sept. 19 | Overcast | 18° /12° | 0.1 mm | 2.4 | |
| Sept. 20 | Overcast | 18° /11° | 1.9 mm | 1.5 | |
| Sept. 21 | Patchy rain possible | 16° /11° | 2.9 mm | 4.4 | |
| Sept. 22 | Overcast | 15° /7° | 0 mm | 3 | |
| Sept. 23 | Overcast | 16° /11° | 0 mm | 5 | |
| Sept. 24 | Sunny | 24° /11° | 0 mm | 6 | |
| Sept. 25 | Sunny | 26° /16° | 0 mm | 6 | |
| Sept. 26 | Overcast | 22° /14° | 5.8 mm | 6 | |
| Sept. 27 | Overcast | 27° /16° | 0 mm | 7 | |
| Sept. 28 | Patchy rain possible | 21° /10° | 1.6 mm | 5 | |
| Sept. 29 | Sunny | 20° /10° | 0 mm | 5 | |
| Sept. 30 | Sunny | 19° /11° | 0 mm | 5 | |
| Next | |||||
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 ☀️
Quick links
More Bismarck weather pages
You are here
Where is Bismarck?Get accurate weather forecasts for Bismarck, located at latitude 46.808 and longitude -100.784. Stay updated with localized weather information tailored for Bismarck.
Found a mistake?
We appreciate your attention to details. Tell us here.