September weather forecastSand Coulee, MT
September
Weather in September
September, the first month of the autumn in Sand Coulee, is still a pleasant month, with temperature in the range of an average low of 50.9°F (10.5°C) and an average high of 70.7°F (21.5°C).Temperature
September indicates a shift in the average high-temperature, from August's moderately hot 81.5°F (27.5°C) to an agreeable 70.7°F (21.5°C). Nighttime temperatures in September average to a cool 50.9°F (10.5°C).Humidity
The average relative humidity in September is 46%.Rainfall
In September, the rain falls for 6 days. Throughout September, 0.67" (17mm) of precipitation is accumulated. In Sand Coulee, during the entire year, the rain falls for 85.3 days and collects up to 9.84" (250mm) of precipitation.Snowfall
January through May, September through December are months with snowfall. September is the first month it typically snows. Throughout September, in the average 0.3 snowfall days, it receives 1.26" (32mm) of snow. In Sand Coulee, during the entire year, snow falls for 58.9 days and aggregates up to 28.54" (725mm) of snow.Daylight
In Sand Coulee, the average length of the day in September is 12h and 32min.On the first day of the month, sunrise is at 6:44 am and sunset at 8:04 pm. On the last day of September, sunrise is at 7:23 am and sunset at 7:05 pm MDT.
Sunshine
The average sunshine in September is 9.8h.UV index
In Sand Coulee, the average daily maximum UV index in September is 4. A UV Index estimate of 3 to 5 represents a medium health hazard from unprotected exposure to Sun's UV rays for average individuals.Note: A maximum high daily UV index of 4 during September translates into the following directions:
Preventative actions are necessary - The mandate to avoid skin and eye damage is in place. Midday is the peak time for the Sun's radiation; stay in the shade and protect yourself. Consider a wide-brim hat essential for effective sun defense covering your face, neck, and eyes. Foresee this! The reflection from snow can nearly double the intensity of UV radiation from the Sun.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Sand Coulee, 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 (30°F).
- Average low temperature in September: 50.9°F
The month with the highest average low temperature is August (58.5°F).
The coldest month (with the lowest average low temperature) is February (18.3°F).
Average pressure in September
Sand Coulee, 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
Sand Coulee, MT
- Average wind speed in September: 8.8mph
The windiest months (with the highest average wind speed) are January and November (11.4mph).
The calmest month (with the lowest average wind speed) is August (7.8mph).
Average humidity in September
Sand Coulee, MT
- Average humidity in September: 46%
The month with the highest relative humidity is January (77%).
The month with the lowest relative humidity is August (40%).
Average rainfall in September
Sand Coulee, MT
- Average rainfall in September: 0.67"
The wettest month (with the highest rainfall) is June (1.57").
The driest month (with the least rainfall) is July (0.47").
Average rainfall days in September
Sand Coulee, MT
- Average rainfall days in September: 6 days
The month with the highest number of rainy days is May (11.7 days).
The months with the least rainy days are November and December (4 days).
Average snowfall in September
Sand Coulee, MT
- Average snowfall in September: 1.26"
The month with the highest snowfall is February (5.67").
The months with the least snowfall are June, July and August (0").
Average snowfall days in September
Sand Coulee, MT
- Average snowfall days in September: 0.3 days
The month with the highest number of snowfall days is February (12.9 days).
The months with the least snowfall days are July and August (0 days).
Average daylight in September /
Average sunshine in September
Sand Coulee, 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 48min
The month with the most sunshine is July (Average sunshine: 12h and 6min).
The months with the least sunshine are January, February and December (Average sunshine: 5h and 36min).
Average sunshine days in September
Sand Coulee, MT
- Average sunshine days in September: 23.1 days
The month with the most sunshine days is July (24.2 days).
The month with the least sunshine days is February (12.4 days).
Average UV index in September
Sand Coulee, 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
Sand Coulee, MT
- Average cloud cover in September: 22
The month with the most cloud cover is February (Cloud cover 46).
The month with the least cloud cover is July (Cloud cover 13).
Average visibility in September
Sand Coulee, 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).





