September weather forecast and climate
Bismarck, ND

An across the park view of the historical building of the State Capitol in Bismarck, North Dakota
An across the park view of the historical building of the State Capitol in Bismarck, North Dakota
September, the first month of the autumn, in Bismarck, is still a pleasant month, with average temperature varying between 52°F (11.1°C) and 72°F (22.2°C).

Temperature

In Bismarck, the average high-temperature drops, from a warm 82.2°F (27.9°C) in August, to a pleasant 72°F (22.2°C). In Bismarck, North Dakota, the average low-temperature is 52°F (11.1°C).

Humidity

The average relative humidity in Bismarck is 57%.

Rainfall

In Bismarck, it is raining for 8.9 days, with typically 1.22" (31mm) of accumulated precipitation. Throughout the year, in Bismarck, 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 12.5h.

Sunshine

The average sunshine in September is 8.6h.

UV index

In Bismarck, the average daily maximum UV index is 4. A UV Index of 3 to 5 symbolizes a medium vulnerability from unprotected exposure to the Sun's UV rays for ordinary individuals.
Note: The average daily UV index of 4 transform into the following instructions:
Take precautions - Protection against sun damage is advised. The solar radiation is most powerful near the mid-day, so the exposure to the direct Sun should be reduced accordingly. Sun-protective clothing, a long-sleeved shirt and pants, a wide-brimmed hat, and UVA and UVB-blocking sunglasses are particularly helpful in blocking UV radiation's harmful effects.

What is the temperature in September in Bismarck?

The average high-temperature, in September, in Bismarck, North Dakota, is 72°F (22.2°C), while the average low-temperature is 52°F (11.1°C).

What is the average humidity in September in Bismarck?

The average relative humidity in September in Bismarck, North Dakota, is 57%.

How many days does it rain in September in Bismarck?

In Bismarck, in September, during 8.9 rainfall days, 1.22" (31mm) of precipitation is typically accumulated.

Does it snow in Bismarck in September?

In Bismarck, in September, it doesn't snow. In October, it regularly snows.

When it does not snow in Bismarck?

June through September are months without snowfall in Bismarck, North Dakota.

How many hours of daylight does Bismarck have in September?

In Bismarck, the average length of the day in September is 12.5h.

How long on average sun shines in September in Bismarck?

In Bismarck, North Dakota, the average sunshine in September is 8.6h.

What is the UV index reading in September in Bismarck?

In September, the average daily maximum UV index in Bismarck is 4. A UV Index of 3 to 5 symbolizes a medium hazard to health from unprotected exposure to the UV radiation.
Average temperature in September - Bismarck, ND
  • Average high temperature in September: 22.2°C

The warmest month (with the highest average high temperature) is July (28.7°C).
The month with the lowest average high temperature is January (-6.2°C).

  • Average low temperature in September: 11.1°C

The month with the highest average low temperature is July (16.3°C).
The coldest month (with the lowest average low temperature) is January (-14.4°C).

Average pressure in September - Bismarck, ND
  • Average pressure in September: 1014.1mbar

The month with the highest atmospheric pressure is February (1021.7mbar).
The month with the lowest atmospheric pressure is June (1010.7mbar).

Average wind speed in September - Bismarck, ND
  • Average wind speed in September: 15.7km/h

The windiest month (with the highest average wind speed) is April (17.2km/h).
The calmest month (with the lowest average wind speed) is August (13.4km/h).

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: 31mm

The wettest month (with the highest rainfall) is June (58mm).
The driest month (with the least rainfall) is January (15mm).

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: 0mm

The month with the highest snowfall is February (110mm).
Months with the least snowfall are June, July, August and September (0mm).

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).
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: 12.5h

The month with the longest days is June (Average daylight: 15.8h).
The month with the shortest days is December (Average daylight: 8.6h).

  • Average sunshine in September: 8.6h

The month with the most sunshine is July (Average sunshine: 11.4h).
The month with the least sunshine is January (Average sunshine: 3.8h).

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).
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).
Months with the least cloud cover are July and August (Cloud cover 21).

Average visibility in September - Bismarck, ND
  • Average visibility in September: 10km

Months with the highest visibility are May, June, July, August, September and October (10km).
Months with the lowest visibility are January, February, March and December (8km).