September weather forecastGrassy Butte, ND
September
Weather in September
September, the first month of the autumn in Grassy Butte, is still a pleasant month, with an average temperature varying between 52.2°F (11.2°C) and 71.2°F (21.8°C).Temperature
The onset of September introduces a moderate change in Grassy Butte's weather, with average high-temperatures falling from August's warm 81.9°F (27.7°C) to a pleasant 71.2°F (21.8°C). Grassy Butte in September anticipates an average nighttime temperature of 52.2°F (11.2°C).Humidity
In September, the average relative humidity is 51%.Rainfall
In September, in Grassy Butte, the rain falls for 8.1 days. Throughout September, 1.61" (41mm) of precipitation is accumulated. Throughout the year, there are 91.6 rainfall days, and 12.64" (321mm) of precipitation is accumulated.Snowfall
June through September are months without snowfall.Daylight
In September, the average length of the day is 12h and 33min.On the first day of the month, sunrise is at 6:12 am and sunset at 7:32 pm. On the last day of September, sunrise is at 6:51 am and sunset at 6:33 pm MDT.
Sunshine
The average sunshine in September is 8.7h.UV index
In Grassy Butte, the average daily maximum UV index in September is 4. A UV Index estimate of 3 to 5 represents a moderate health risk from exposure to the Sun's UV radiation for average individuals.Note: In September, the maximum UV index of 4 translates into these guidelines:
Prioritize safety - Recommendations to avert sunburn are shared. For skin protection, it's recommended to minimize Sun exposure during its peak hours around midday. Select sunglasses that boast both UVA and UVB protection to limit the adverse effects of the sun on the eyes.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Grassy Butte, 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 January (21.4°F).
- Average low temperature in September: 52.2°F
The month with the highest average low temperature is July (61°F).
The coldest month (with the lowest average low temperature) is January (7.3°F).
Average pressure in September
Grassy Butte, 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
Grassy Butte, ND
- Average wind speed in September: 10mph
The windiest month (with the highest average wind speed) is April (11mph).
The calmest month (with the lowest average wind speed) is August (8.9mph).
Average humidity in September
Grassy Butte, ND
- Average humidity in September: 51%
The month with the highest relative humidity is January (89%).
The month with the lowest relative humidity is August (49%).
Average rainfall in September
Grassy Butte, ND
- Average rainfall in September: 1.61"
The wettest month (with the highest rainfall) is June (1.85").
The driest months (with the least rainfall) are January and February (0.43").
Average rainfall days in September
Grassy Butte, ND
- Average rainfall days in September: 8.1 days
The month with the highest number of rainy days is June (12.6 days).
The month with the least rainy days is February (2.9 days).
Average snowfall in September
Grassy Butte, ND
- Average snowfall in September: 0"
The month with the highest snowfall is December (3.07").
The months with the least snowfall are June, July, August and September (0").
Average snowfall days in September
Grassy Butte, ND
- Average snowfall days in September: 0 days
The months with the highest number of snowfall days are January and December (11.2 days).
The months with the least snowfall days are June, July, August and September (0 days).
Average daylight in September /
Average sunshine in September
Grassy Butte, ND
- Average daylight in September: 12h and 30min
The month with the longest days is June (Average daylight: 15h and 54min).
The month with the shortest days is December (Average daylight: 8h and 30min).
- Average sunshine in September: 8h and 42min
The month with the most sunshine is July (Average sunshine: 11h and 36min).
The months with the least sunshine are January and December (Average sunshine: 4h and 0min).
Average sunshine days in September
Grassy Butte, ND
- Average sunshine days in September: 20.5 days
The month with the most sunshine days is September (20.5 days).
The month with the least sunshine days is April (14.9 days).
Average UV index in September
Grassy Butte, 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
Grassy Butte, ND
- Average cloud cover in September: 25
The month with the most cloud cover is February (Cloud cover 61).
The months with the least cloud cover are July and August (Cloud cover 19).
Average visibility in September
Grassy Butte, ND
- Average visibility in September: 6mi
The months with the highest visibility are March, April, May, June, July, August, September, October and November (6mi).
The months with the lowest visibility are January, February and December (5mi).
