September weather forecastSun Prairie, MT
September
Weather in September
The first month of the autumn, September, is still a pleasant month in Sun Prairie, Montana, with temperature in the range of an average low of 50.2°F (10.1°C) and an average high of 70.7°F (21.5°C).Temperature
In September, the meteorological conditions alter, with the average high-temperature shifting from a warm 81.5°F (27.5°C) in August to an agreeable 70.7°F (21.5°C). Throughout September, the temperature falls to an average low of 50.2°F (10.1°C).Humidity
In September, the average relative humidity is 47%.Rainfall
In Sun Prairie, during September, the rain falls for 7.9 days and regularly aggregates up to 0.98" (25mm) of precipitation. Throughout the year, there are 102.6 rainfall days, and 11.89" (302mm) of precipitation is accumulated.Snowfall
Months with snowfall are January through May, September through December. September is the first month it typically snows. Throughout September, in the average 0.7 snowfall days, it receives 1.61" (41mm) of snow. In Sun Prairie, during the entire year, snow falls for 66.6 days and aggregates up to 32.17" (817mm) of snow.Daylight
In September, the average length of the day is 12h and 33min.On the first day of September, sunrise is at 6:45 am and sunset at 8:05 pm. On the last day of the month, sunrise is at 7:24 am and sunset at 7:06 pm MDT.
Sunshine
In September, the average sunshine in Sun Prairie is 9.7h.UV index
In Sun Prairie, the average daily maximum UV index in September is 4. A UV Index estimate of 3 to 5 represents a medium health hazard from exposure to the Sun's UV radiation for the ordinary person.Note: The UV index of 4 during September leads to these advisories:
Adopt protective measures - It is advised to guard against sun damage. Avoid the Sun's strongest UV rays by seeking shade and limiting exposure during midday. Shield yourself from the harmful effects of UV radiation with sun-protective attire, a hat, and quality sunglasses. Take heed! Reflection from the snow can almost amplify the Sun's UV radiation by double.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Sun Prairie, MT
- Average high temperature in September: 70.7°F
The warmest month (with the highest average high temperature) is July (82.9°F).
The month with the lowest average high temperature is December (29.8°F).
- Average low temperature in September: 50.2°F
The month with the highest average low temperature is August (57.6°F).
The coldest month (with the lowest average low temperature) is December (18.1°F).
Average pressure in September
Sun Prairie, MT
- Average pressure in September: 29.95"Hg
The month with the highest atmospheric pressure is January (30.14"Hg).
The month with the lowest atmospheric pressure is June (29.87"Hg).
Average wind speed in September
Sun Prairie, MT
- Average wind speed in September: 8.5mph
The windiest month (with the highest average wind speed) is November (11.2mph).
The calmest month (with the lowest average wind speed) is August (7.5mph).
Average humidity in September
Sun Prairie, MT
- Average humidity in September: 47%
The month with the highest relative humidity is January (77%).
The month with the lowest relative humidity is August (41%).
Average rainfall in September
Sun Prairie, MT
- Average rainfall in September: 0.98"
The wettest month (with the highest rainfall) is June (1.97").
The driest months (with the least rainfall) are January and July (0.59").
Average rainfall days in September
Sun Prairie, MT
- Average rainfall days in September: 7.9 days
The month with the highest number of rainy days is May (14.5 days).
The month with the least rainy days is November (4.4 days).
Average snowfall in September
Sun Prairie, MT
- Average snowfall in September: 1.61"
The month with the highest snowfall is February (5.28").
The months with the least snowfall are June, July and August (0").
Average snowfall days in September
Sun Prairie, MT
- Average snowfall days in September: 0.7 days
The month with the highest number of snowfall days is February (12.6 days).
The months with the least snowfall days are July and August (0 days).
Average daylight in September /
Average sunshine in September
Sun Prairie, 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: 9h and 42min
The month with the most sunshine is July (Average sunshine: 12h and 0min).
The months with the least sunshine are January, February and December (Average sunshine: 5h and 30min).
Average sunshine days in September
Sun Prairie, MT
- 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 (11.6 days).
Average UV index in September
Sun Prairie, MT
- 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 January, February, March, October, November and December (UV index 2).
Average cloud cover in September
Sun Prairie, MT
- Average cloud cover in September: 23
The month with the most cloud cover is February (Cloud cover 47).
The month with the least cloud cover is July (Cloud cover 13).
Average visibility in September
Sun Prairie, MT
- Average visibility in September: 6mi
The months with the highest visibility are January, February, March, April, May, June, July, August, September, October, November and December (6mi).
The months with the lowest visibility are January, February, March, April, May, June, July, August, September, October, November and December (6mi).
