September weather forecast
Mandan, ND

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Scenic fields and vast spaces laden with green trees and shrubs in this place near the Mandan Community of North Dakota
Scenic fields and vast spaces laden with green trees and shrubs in this place near the Mandan Community of North Dakota

Weather in September

Come September, Mandan witnesses a shift towards autumn, marked by gradually falling temperatures and shifting weather patterns. The highest recorded temperature in this month falls to 71.8°F (22.1°C) from August's average of 82°F (27.8°C). Rainfall also sees a minor decline, and snow is a rarity, indicating the onset of the fall season. With 12.5 hours of daylight on average, the glow of autumn appears under a more mellow sun.

Temperature

With the onset of September, Mandan's average high-temperature adjusts, receding from August's moderately hot 82°F (27.8°C) to an agreeable 71.8°F (22.1°C). The average nighttime temperature lowers to a cool 51.8°F (11°C) throughout September.

Humidity

In Mandan, the average relative humidity in September is 57%.

Rainfall

In September, in Mandan, the rain falls for 8.9 days. Throughout September, 1.46" (37mm) of precipitation is accumulated. In Mandan, during the entire year, the rain falls for 94.3 days and collects up to 14.29" (363mm) of precipitation.

Snowfall

June through September are months without snowfall in Mandan.

Daylight

The average length of the day in September in Mandan is 12h and 32min.
On the first day of September, sunrise is at 7:04 am and sunset at 8:22 pm. On the last day of the month, sunrise is at 7:42 am and sunset at 7:24 pm CDT.

Sunshine

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

UV index

The average daily maximum UV index in September is 4. A UV Index of 3 to 5 symbolizes a moderate health risk from exposure to the Sun's UV rays for the average person.
Note: The maximum daily UV index, 4 in September, converts into the following recommendations:
Adopt protective measures - It is advised to guard against sun damage. Sun's radiation is most powerful around mid-day, so it's best to limit outdoor activities during this time. Tightly woven clothing, when worn loosely, shields effectively against the Sun.
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Frequently asked questions

What are the temperatures in Mandan in September?

The average high-temperature and low-temperature during September are 71.8°F (22.1°C) and 51.8°F (11°C) respectively. In August, the average heat index (a.k.a. 'felt air temperature', 'feels like'), which represents the influence of relative humidity on air temperature, is calculated to be 84.2°F (29°C).

What is the average humidity in September in Mandan?

In Mandan, North Dakota, the average relative humidity in September is 57%.

How much does it rain in Mandan in September?

In September, in Mandan, the rain falls for 8.9 days. Throughout September, 1.46" (37mm) of precipitation is accumulated.

When it does not snow in Mandan?

June through September are months without snowfall in Mandan.

Does it snow in Mandan in September?

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

What is the average length of the day in September in Mandan?

In Mandan, the average day length in September is 12h and 32min.

What time are sunrise and sunset in September in Mandan?

On the first day of September in Mandan, North Dakota, sunrise is at 7:04 am and sunset at 8:22 pm. On the last day of the month, sunrise is at 7:42 am and sunset at 7:24 pm CDT.

How long on average sun shines in September in Mandan?

The average sunshine duration in September in Mandan, North Dakota, is 8.6h.

What is the UV index intensity in September in Mandan?

In September, the average daily maximum UV index in Mandan, North Dakota, is 4. A UV Index of 3 to 5 symbolizes a medium health risk from exposure to the Sun's UV radiation.
Average humidity
Average rainfall days
Average snowfall
Average snowfall days
Average daylight
Average sunshine
Average sunshine days
Average UV index
Average cloud cover
Average visibility

Average temperature in September
Mandan, ND

Average temperature in September - Mandan, ND
  • Average high temperature in September: 71.8°F

The warmest month (with the highest average high temperature) is July (83.5°F).
The month with the lowest average high temperature is January (20.7°F).

  • Average low temperature in September: 51.8°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 (6.3°F).

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Average pressure in September
Mandan, ND

Average pressure in September - Mandan, 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).

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Average wind speed in September
Mandan, ND

Average wind speed in September - Mandan, ND
  • Average wind speed in September: 9.9mph

The windiest months (with the highest average wind speed) are April and October (10.8mph).
The calmest month (with the lowest average wind speed) is August (8.5mph).

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Average humidity in September
Mandan, ND

Average humidity in September - Mandan, 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%).

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Average rainfall in September
Mandan, ND

Average rainfall in September - Mandan, ND
  • Average rainfall in September: 1.46"

The wettest month (with the highest rainfall) is June (2.32").
The driest month (with the least rainfall) is January (0.43").

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Average rainfall days in September
Mandan, ND

Average rainfall days in September - Mandan, ND
  • Average rainfall days in September: 8.9 days

The month with the highest number of rainy days is June (13.1 days).
The month with the least rainy days is February (2.3 days).

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Average snowfall in September
Mandan, ND

Average snowfall in September - Mandan, ND
  • Average snowfall in September: 0"

The month with the highest snowfall is December (3.31").
The months with the least snowfall are June, July, August and September (0").

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Average snowfall days in September
Mandan, ND

Average snowfall days in September - Mandan, ND
  • Average snowfall days in September: 0 days

The month with the highest number of snowfall days is December (12.8 days).
The months with the least snowfall days are June, July, August and September (0 days).

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Average daylight in September /
Average sunshine in September
Mandan, ND

Average daylight in September / Average sunshine in September - Mandan, ND
  • Average daylight in September: 12h and 3min

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 4min

The month with the most sunshine is July (Average sunshine: 11h and 18min).
The month with the least sunshine is January (Average sunshine: 3h and 54min).

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Average sunshine days in September
Mandan, ND

Average sunshine days in September - Mandan, ND
  • Average sunshine days in September: 20.1 days

The month with the most sunshine days is November (20.2 days).
The month with the least sunshine days is June (14.6 days).

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Average UV index in September
Mandan, ND

Average UV index in September - Mandan, 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 November and December (UV index 1).

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Average cloud cover in September
Mandan, ND

Average cloud cover in September - Mandan, ND
  • Average cloud cover in September: 25

The month with the most cloud cover is February (Cloud cover 60).
The month with the least cloud cover is August (Cloud cover 21).

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Average visibility in September
Mandan, ND

Average visibility in September - Mandan, 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).

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Mandan, North Dakota, USA

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