September weather forecastWilliston, ND
September
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.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
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).
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).
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).
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%).
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").
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).
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").
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).
Average daylight in September /
Average sunshine in September
Williston, ND
- Average daylight in September: 12h and 36min
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 36min
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).
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).
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).
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).
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).
