September weather forecastBismarck, ND
September
Weather in September
September ushers in fall in Bismarck, demonstrated by cooler temperatures, less rain, and the onset of the foliage transition. Notwithstanding the decrease from the summer heat, Bismarck experiences rainfall of 1.22" (31mm). Remaining relatively mild, September serves a gentle transition between the hot summer days to the cooler times of autumn. Towards the end of September, the first traces of the fall foliage adorn the cityscape of Bismarck.Temperature
As September begins in Bismarck, there is a decrease in the average high-temperature, falling from a moderately hot 82.2°F (27.9°C) in August to a pleasant 72°F (22.2°C). In Bismarck, in September, the average low-temperature is a cool 52°F (11.1°C).Humidity
In Bismarck, the average relative humidity in September is 57%.Rainfall
In Bismarck, in September, during 8.9 rainfall days, 1.22" (31mm) of precipitation is typically accumulated. Throughout the year, there are 105.9 rainfall days, and 15" (381mm) of precipitation is accumulated.Snowfall
June through September are months without snowfall.Daylight
In Bismarck, the average length of the day in September is 12h and 32min.On the first day of September, sunrise is at 7:03 am and sunset at 8:21 pm. On the last day of the month, sunrise is at 7:41 am and sunset at 7:24 pm CDT.
Sunshine
In September, the average sunshine is 8.6h.UV index
In September, the average daily maximum UV index is 4. A UV Index value of 3 to 5 symbolizes a medium health hazard from unsafe exposure to UV radiation for the average person.Note: The maximum daily UV index of 4 during September translates into the following directions:
Be cautious. Those with fair skin can be subjected to burns in fewer than 30 minutes. Minimize direct exposure to the Sun during midday when its radiation is at its peak. In the presence of strong sunlight, it's crucial to wear sunglasses that ward off UVA and UVB rays.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Bismarck, ND
- Average high temperature in September: 72°F
The warmest month (with the highest average high temperature) is July (83.7°F).
The month with the lowest average high temperature is January (20.8°F).
- Average low temperature in September: 52°F
The month with the highest average low temperature is July (61.3°F).
The coldest month (with the lowest average low temperature) is January (6.1°F).
Average pressure in September
Bismarck, ND
- Average pressure in September: 29.95"Hg
The month with the highest atmospheric pressure is February (30.17"Hg).
The month with the lowest atmospheric pressure is June (29.85"Hg).
Average wind speed in September
Bismarck, ND
- Average wind speed in September: 9.8mph
The windiest month (with the highest average wind speed) is April (10.7mph).
The calmest month (with the lowest average wind speed) is August (8.3mph).
Average humidity in September
Bismarck, ND
- Average humidity in September: 57%
The month with the highest relative humidity is January (89%).
The month with the lowest relative humidity is August (55%).
Average rainfall in September
Bismarck, ND
- Average rainfall in September: 1.22"
The wettest month (with the highest rainfall) is June (2.28").
The driest month (with the least rainfall) is January (0.59").
Average rainfall days in September
Bismarck, ND
- Average rainfall days in September: 8.9 days
The month with the highest number of rainy days is May (15.5 days).
The month with the least rainy days is February (3.4 days).
Average snowfall in September
Bismarck, ND
- Average snowfall in September: 0"
The month with the highest snowfall is February (4.33").
The months with the least snowfall are June, July, August and September (0").
Average snowfall days in September
Bismarck, ND
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is December (15.7 days).
The months with the least snowfall days are June, July, August and September (0 days).
Average daylight in September /
Average sunshine in September
Bismarck, ND
- Average daylight in September: 12h and 30min
The month with the longest days is June (Average daylight: 15h and 48min).
The month with the shortest days is December (Average daylight: 8h and 36min).
- Average sunshine in September: 8h and 36min
The month with the most sunshine is July (Average sunshine: 11h and 24min).
The month with the least sunshine is January (Average sunshine: 3h and 48min).
Average sunshine days in September
Bismarck, ND
- Average sunshine days in September: 19.9 days
The month with the most sunshine days is September (19.9 days).
The month with the least sunshine days is March (12.3 days).
Average UV index in September
Bismarck, ND
- Average UV index in September: 4
The month with the highest UV index is July (UV index 6).
The months with the lowest UV index are January, November and December (UV index 1).
Average cloud cover in September
Bismarck, ND
- Average cloud cover in September: 25
The month with the most cloud cover is February (Cloud cover 60).
The months with the least cloud cover are July and August (Cloud cover 21).
Average visibility in September
Bismarck, ND
- Average visibility in September: 6mi
The months with the highest visibility are April, May, June, July, August, September, October and November (6mi).
The months with the lowest visibility are January, February, March and December (5mi).
