September weather forecastVan Norman, MT
September
Weather in September
The first month of the autumn, September, is still a pleasant month in Van Norman, Montana, with an average temperature ranging between min 54.9°F (12.7°C) and max 71.2°F (21.8°C).Temperature
September comes with a decrease in the average high-temperature, falling from a moderately hot 82.6°F (28.1°C) in August to an agreeable 71.2°F (21.8°C). An average low-temperature of 54.9°F (12.7°C) is recorded in the month of September.Humidity
In September, the average relative humidity is 44%.Rainfall
In September, the rain falls for 8.7 days. Throughout September, 1.1" (28mm) of precipitation is accumulated. Throughout the year, there are 104.8 rainfall days, and 13.03" (331mm) of precipitation is accumulated.Snowfall
January through May, September through December are months with snowfall. September is the first month it typically snows. Throughout September, in the average 0.1 snowfall days, it receives 0.04" (1mm) of snow. Throughout the year, there are 58.4 snowfall days, and 21.1" (536mm) of snow is accumulated.Daylight
The average length of the day in September is 12h and 32min.On the first day of September in Van Norman, sunrise is at 6:25 am and sunset at 7:44 pm. On the last day of the month, sunrise is at 7:04 am and sunset at 6:46 pm MDT.
Sunshine
In Van Norman, the average sunshine in September is 10.1h.UV index
In September, the average daily maximum UV index is 4. A UV Index reading of 3 to 5 represents a medium health hazard from unsafe exposure to UV radiation for the ordinary person.Note: The UV index of 4 during September leads to these advisories:
Be vigilant - A duty to shield skin and eyes from injury exists. The mid-day Sun emits the most powerful UV radiation, so seek shade and minimize exposure. Loose clothes with a tight weave are optimal for safeguarding yourself against the Sun's rays. Notice! The UV radiation of the Sun can be intensified nearly twofold due to the reflective quality of snow.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Van Norman, MT
- Average high temperature in September: 71.2°F
The warmest month (with the highest average high temperature) is July (83.8°F).
The month with the lowest average high temperature is January (27.7°F).
- Average low temperature in September: 54.9°F
The month with the highest average low temperature is July (64.4°F).
The coldest month (with the lowest average low temperature) is January (14.7°F).
Average pressure in September
Van Norman, MT
- Average pressure in September: 29.92"Hg
The months with the highest atmospheric pressure are January and February (30.14"Hg).
The month with the lowest atmospheric pressure is June (29.83"Hg).
Average wind speed in September
Van Norman, MT
- Average wind speed in September: 10.5mph
The windiest month (with the highest average wind speed) is April (12mph).
The calmest month (with the lowest average wind speed) is February (9.9mph).
Average humidity in September
Van Norman, MT
- Average humidity in September: 44%
The month with the highest relative humidity is January (82%).
The month with the lowest relative humidity is August (40%).
Average rainfall in September
Van Norman, MT
- Average rainfall in September: 1.1"
The wettest months (with the highest rainfall) are May and June (1.89").
The driest month (with the least rainfall) is November (0.63").
Average rainfall days in September
Van Norman, MT
- Average rainfall days in September: 8.7 days
The month with the highest number of rainy days is May (14.5 days).
The month with the least rainy days is February (3.7 days).
Average snowfall in September
Van Norman, MT
- Average snowfall in September: 0.04"
The month with the highest snowfall is December (4.45").
The months with the least snowfall are June, July and August (0").
Average snowfall days in September
Van Norman, MT
- Average snowfall days in September: 0.1 days
The month with the highest number of snowfall days is December (12.5 days).
The months with the least snowfall days are July and August (0 days).
Average daylight in September /
Average sunshine in September
Van Norman, MT
- 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: 10h and 6min
The month with the most sunshine is July (Average sunshine: 11h and 54min).
The months with the least sunshine are January and February (Average sunshine: 4h and 54min).
Average sunshine days in September
Van Norman, MT
- Average sunshine days in September: 18.7 days
The month with the most sunshine days is November (19.1 days).
The month with the least sunshine days is April (12.3 days).
Average UV index in September
Van Norman, MT
- Average UV index in September: 4
The month with the highest UV index is July (UV index 7).
The month with the lowest UV index is December (UV index 1).
Average cloud cover in September
Van Norman, MT
- Average cloud cover in September: 23
The month with the most cloud cover is February (Cloud cover 49).
The months with the least cloud cover are July and August (Cloud cover 16).
Average visibility in September
Van Norman, MT
- Average visibility in September: 6mi
The months with the highest visibility are February, March, April, May, June, July, August, September, October, November and December (6mi).
The month with the lowest visibility is January (5mi).
