September weather forecastRapelje, MT
September
Weather in September
September, the first month of the autumn in Rapelje, is also an agreeable month, with temperature in the range of an average low of 50°F (10°C) and an average high of 72°F (22.2°C).Temperature
In the transition to September, Rapelje observes a drop in the average high-temperature, moving from a warm 81.1°F (27.3°C) in August to an agreeable 72°F (22.2°C). In Rapelje, the September nights descend to a significantly cooler average of 50°F (10°C) compared to daytime highs.Humidity
In September, the average relative humidity is 45%.Rainfall
In Rapelje, in September, it is raining for 7.8 days, with typically 0.79" (20mm) of accumulated precipitation. Throughout the year, there are 125.4 rainfall days, and 14.49" (368mm) 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 0.3 snowfall days, it receives 0.24" (6mm) of snow. In Rapelje, Montana, during the entire year, snow falls for 63.3 days and aggregates up to 39.09" (993mm) of snow.Daylight
In September, the average length of the day is 12h and 31min.On the first day of the month, sunrise is at 6:38 am and sunset at 7:54 pm. On the last day of September, sunrise is at 7:15 am and sunset at 6:58 pm MDT.
Sunshine
In September, the average sunshine is 10.5h.UV index
In September, the average daily maximum UV index is 4. A UV Index estimate of 3 to 5 represents a moderate health risk from exposure to the Sun's UV rays for the ordinary person.Note: A maximum daily UV index of 4 during September morphs into the following directions:
Take care. Persons with lighter skin might suffer burns in less than 30 minutes. Considering the harmful UV rays from the Sun during midday, it's essential to reduce exposure. Sunglasses providing both UVA and UVB protection are non-negotiable on sunlit days. Consider this! The reflection from snow can almost double the intensity of the Sun's UV radiation.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Rapelje, MT
- Average high temperature in September: 72°F
The warmest month (with the highest average high temperature) is July (82.6°F).
The month with the lowest average high temperature is December (30.9°F).
- Average low temperature in September: 50°F
The month with the highest average low temperature is August (57.2°F).
The coldest month (with the lowest average low temperature) is February (17.4°F).
Average pressure in September
Rapelje, MT
- Average pressure in September: 29.96"Hg
The months with the highest atmospheric pressure are January and December (30.15"Hg).
The month with the lowest atmospheric pressure is June (29.88"Hg).
Average wind speed in September
Rapelje, MT
- Average wind speed in September: 7.1mph
The windiest month (with the highest average wind speed) is January (8.9mph).
The calmest month (with the lowest average wind speed) is August (6.1mph).
Average humidity in September
Rapelje, MT
- Average humidity in September: 45%
The month with the highest relative humidity is January (76%).
The month with the lowest relative humidity is August (41%).
Average rainfall in September
Rapelje, MT
- Average rainfall in September: 0.79"
The wettest month (with the highest rainfall) is May (2.6").
The driest month (with the least rainfall) is January (0.63").
Average rainfall days in September
Rapelje, MT
- Average rainfall days in September: 7.8 days
The month with the highest number of rainy days is May (17.5 days).
The month with the least rainy days is February (6.7 days).
Average snowfall in September
Rapelje, MT
- Average snowfall in September: 0.24"
The month with the highest snowfall is February (7.36").
The months with the least snowfall are June, July and August (0").
Average snowfall days in September
Rapelje, MT
- Average snowfall days in September: 0.3 days
The month with the highest number of snowfall days is February (13.4 days).
The months with the least snowfall days are June, July and August (0 days).
Average daylight in September /
Average sunshine in September
Rapelje, MT
- Average daylight in September: 12h and 30min
The month with the longest days is June (Average daylight: 15h and 42min).
The month with the shortest days is December (Average daylight: 8h and 42min).
- Average sunshine in September: 10h and 30min
The month with the most sunshine is July (Average sunshine: 12h and 0min).
The months with the least sunshine are February and December (Average sunshine: 6h and 12min).
Average sunshine days in September
Rapelje, MT
- Average sunshine days in September: 18.9 days
The month with the most sunshine days is September (18.9 days).
The month with the least sunshine days is April (9.5 days).
Average UV index in September
Rapelje, 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, November and December (UV index 2).
Average cloud cover in September
Rapelje, MT
- Average cloud cover in September: 19
The month with the most cloud cover is February (Cloud cover 39).
The month with the least cloud cover is August (Cloud cover 14).
Average visibility in September
Rapelje, 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).
