September weather forecastRiverview Colony, MT
September
Weather in September
The first month of the autumn, September, is still a pleasant month in Riverview Colony, Montana, with an average temperature ranging between min 52°F (11.1°C) and max 70.2°F (21.2°C).Temperature
September involves a decrease in temperature, down from a moderately hot 81.1°F (27.3°C) in August to an agreeable 70.2°F (21.2°C). In Riverview Colony, September is marked by an average low-temperature of 52°F (11.1°C).Humidity
In September, the average relative humidity is 45%.Rainfall
In Riverview Colony, in September, during 8.6 rainfall days, 0.98" (25mm) of precipitation is typically accumulated. Throughout the year, there are 113.8 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 in Riverview Colony. Throughout September, in the average 0.5 snowfall days, it receives 0.67" (17mm) of snow. In Riverview Colony, during the entire year, snow falls for 65.1 days and aggregates up to 24.69" (627mm) of snow.Daylight
In Riverview Colony, Montana, the average length of the day in September is 12h and 34min.On the first day of the month, sunrise is at 6:43 am and sunset at 8:04 pm. On the last day of September, sunrise is at 7:23 am and sunset at 7:04 pm MDT.
Sunshine
In September, the average sunshine is 9.9h.UV index
The average daily maximum UV index in September is 4. A UV Index reading of 3 to 5 represents a medium health hazard from exposure to the Sun's UV radiation for ordinary individuals.Note: The maximum UV index, 4 during September, leads to the following recommendations:
Undertake precautions - It is suggested to shield oneself from sunburn. Stay safe from the Sun's strongest UV rays by limiting exposure during midday. On sunny days, it's ideal to wear sunglasses that filter out UVA and UVB rays. Mind you! Snow reflection can increase the intensity of the Sun's UV radiation nearly twofold.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Riverview Colony, MT
- Average high temperature in September: 70.2°F
The warmest month (with the highest average high temperature) is July (82°F).
The month with the lowest average high temperature is December (28.2°F).
- Average low temperature in September: 52°F
The month with the highest average low temperature is August (60.4°F).
The coldest month (with the lowest average low temperature) is February (16.3°F).
Average pressure in September
Riverview Colony, MT
- Average pressure in September: 29.94"Hg
The month with the highest atmospheric pressure is January (30.13"Hg).
The month with the lowest atmospheric pressure is June (29.85"Hg).
Average wind speed in September
Riverview Colony, MT
- Average wind speed in September: 9.3mph
The windiest month (with the highest average wind speed) is April (10.8mph).
The calmest month (with the lowest average wind speed) is August (8.5mph).
Average humidity in September
Riverview Colony, MT
- Average humidity in September: 45%
The month with the highest relative humidity is January (81%).
The month with the lowest relative humidity is August (39%).
Average rainfall in September
Riverview Colony, MT
- Average rainfall in September: 0.98"
The wettest month (with the highest rainfall) is June (2.32").
The driest month (with the least rainfall) is December (0.59").
Average rainfall days in September
Riverview Colony, MT
- Average rainfall days in September: 8.6 days
The month with the highest number of rainy days is May (14.9 days).
The month with the least rainy days is January (5 days).
Average snowfall in September
Riverview Colony, MT
- Average snowfall in September: 0.67"
The month with the highest snowfall is February (5").
The months with the least snowfall are June, July and August (0").
Average snowfall days in September
Riverview Colony, MT
- Average snowfall days in September: 0.5 days
The month with the highest number of snowfall days is January (12.5 days).
The months with the least snowfall days are June, July and August (0 days).
Average daylight in September /
Average sunshine in September
Riverview Colony, MT
- 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: 9h and 54min
The month with the most sunshine is July (Average sunshine: 12h and 0min).
The months with the least sunshine are January and December (Average sunshine: 5h and 18min).
Average sunshine days in September
Riverview Colony, MT
- Average sunshine days in September: 19.5 days
The month with the most sunshine days is September (19.5 days).
The month with the least sunshine days is April (11.7 days).
Average UV index in September
Riverview Colony, 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
Riverview Colony, 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 15).
Average visibility in September
Riverview Colony, 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).





