September weather forecast
Williston, ND

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Weather in September

September in Williston serves as a gentle bridge from the high energy of summer to the serene entrance of fall. Arguably, an increase in rainfall to 1.61" (41mm) signifies a shift in seasonal patterns. As temperatures start to fall, the city embraces the first signs of autumn: crisp air, colorful leaves, and early twilight. The metamorphosis from summer to fall leaves an indelible mark on the September weather of Williston.

Temperature

Williston experiences a temperature shift at the start of September, with average high-temperatures adjusting from a moderately hot 82°F (27.8°C) in August to a pleasant 71.2°F (21.8°C). In the month of September, the average temperature dips to a cool 52.7°F (11.5°C) during the night.

Humidity

In September, the average relative humidity is 50%.

Rainfall

In Williston, in September, it is raining for 9.1 days, with typically 1.61" (41mm) of accumulated precipitation. In Williston, during the entire year, the rain falls for 94.7 days and collects up to 12.52" (318mm) of precipitation.

Snowfall

June through September are months without snowfall in Williston.

Daylight

In September, the average length of the day in Williston is 12h and 34min.
On the first day of September in Williston, sunrise is at 7:13 am and sunset at 8:34 pm. On the last day of the month, sunrise is at 7:53 am and sunset at 7:34 pm CDT.

Sunshine

In September, the average sunshine in Williston is 8.6h.

UV index

In September, the average daily maximum UV index is 4. A UV Index of 3 to 5 symbolizes a moderate health risk from exposure to the Sun's UV rays for the ordinary person.
Note: A daily maximum UV index of 4 in September translates into the following instructions:
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. To cut down UV radiation exposure by about half, sport a wide-brim hat. Mark this! Snow reflection can nearly double the UV radiation intensity from the Sun.
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Frequently asked questions

What is the average September temperature in Williston?

An average high-temperature, in September, in Williston, is 71.2°F (21.8°C) and the average low-temperature is 52.7°F (11.5°C). The average heat index (a.k.a. 'real feel', 'apparent temperature'), which combines air temperature and relative humidity, in August is evaluated at 82.4°F (28°C).

What is the average humidity in September in Williston?

In September, the average relative humidity in Williston is 50%.

How many days does it rain in September in Williston?

In Williston, North Dakota, during September, the rain falls for 9.1 days and regularly aggregates up to 1.61" (41mm) of precipitation.

When it does not snow in Williston?

In Williston, snow does not fall in June through September.

Does it snow in Williston in September?

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

How many hours of daylight does Williston have in September?

The average day length in September in Williston is 12h and 34min.

When is the sunrise / sunset in September in Williston?

In September, on the first day of the month, sunrise is at 7:13 am and sunset at 8:34 pm. On the last day of the month, sunrise is at 7:53 am and sunset at 7:34 pm CDT.

How many hours of sunshine does Williston have in September?

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

What is the UV index reading in September in Williston?

In Williston, the average daily maximum UV index in September is 4. A UV Index value of 3 to 5 symbolizes a moderate vulnerability 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
Williston, ND

Average temperature in September - Williston, ND
  • Average high temperature in September: 71.2°F

The warmest month (with the highest average high temperature) is July (83.1°F).
The month with the lowest average high temperature is February (20.8°F).

  • Average low temperature in September: 52.7°F

The month with the highest average low temperature is July (61.3°F).
The coldest months (with the lowest average low temperature) are January and February (7°F).

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Average pressure in September
Williston, ND

Average pressure in September - Williston, ND
  • Average pressure in September: 29.93"Hg

The month with the highest atmospheric pressure is February (30.17"Hg).
The month with the lowest atmospheric pressure is June (29.84"Hg).

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Average wind speed in September
Williston, ND

Average wind speed in September - Williston, ND
  • Average wind speed in September: 10mph

The windiest month (with the highest average wind speed) is April (11.1mph).
The calmest month (with the lowest average wind speed) is February (8.9mph).

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Average humidity in September
Williston, ND

Average humidity in September - Williston, ND
  • Average humidity in September: 50%

The month with the highest relative humidity is January (89%).
The month with the lowest relative humidity is August (48%).

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Average rainfall in September
Williston, ND

Average rainfall in September - Williston, ND
  • Average rainfall in September: 1.61"

The wettest month (with the highest rainfall) is June (2.05").
The driest month (with the least rainfall) is December (0.35").

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Average rainfall days in September
Williston, ND

Average rainfall days in September - Williston, ND
  • Average rainfall days in September: 9.1 days

The month with the highest number of rainy days is June (14.2 days).
The month with the least rainy days is December (2.5 days).

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Average snowfall in September
Williston, ND

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

The month with the highest snowfall is February (3.07").
The months with the least snowfall are June, July, August and September (0").

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Average snowfall days in September
Williston, ND

Average snowfall days in September - Williston, ND
  • Average snowfall days in September: 0.1 days

The month with the highest number of snowfall days is February (12.3 days).
The months with the least snowfall days are June, July and August (0 days).

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

Average daylight in September / Average sunshine in September - Williston, ND
  • Average daylight in September: 12h and 4min

The month with the longest days is June (Average daylight: 16h and 0min).
The month with the shortest days is December (Average daylight: 8h and 24min).

  • Average sunshine in September: 8h and 4min

The month with the most sunshine is July (Average sunshine: 11h and 36min).
The month with the least sunshine is December (Average sunshine: 4h and 0min).

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Average sunshine days in September
Williston, ND

Average sunshine days in September - Williston, ND
  • Average sunshine days in September: 19.4 days

The month with the most sunshine days is November (21.1 days).
The month with the least sunshine days is June (13.5 days).

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Average UV index in September
Williston, ND

Average UV index in September - Williston, ND
  • Average UV index in September: 4

The months with the highest UV index are June, July and August (UV index 6).
The months with the lowest UV index are February and December (UV index 1).

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Average cloud cover in September
Williston, ND

Average cloud cover in September - Williston, ND
  • Average cloud cover in September: 26

The month with the most cloud cover is February (Cloud cover 61).
The month with the least cloud cover is July (Cloud cover 19).

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Average visibility in September
Williston, ND

Average visibility in September - Williston, ND
  • Average visibility in September: 6mi

The months with the highest visibility are March, April, May, June, July, August, September, October, November and December (6mi).
The months with the lowest visibility are January and February (5mi).

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Williston, North Dakota, USA

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