September weather forecastActon, MT
September
Weather in September
The first month of the autumn, September, is still a pleasant month in Acton, Montana, with an average temperature varying between 73.2°F (22.9°C) and 52.5°F (11.4°C).Temperature
As September arrives, Acton's weather displays a decrease in high-temperatures, transitioning from August's moderately hot 83.5°F (28.6°C) to an agreeable 73.2°F (22.9°C). In Acton, an average nighttime temperature of 52.5°F (11.4°C) is expected during September.Humidity
In September, the average relative humidity in Acton is 44%.Rainfall
In September, in Acton, Montana, the rain falls for 6.8 days. Throughout September, 0.67" (17mm) of precipitation is accumulated. In Acton, during the entire year, the rain falls for 120.5 days and collects up to 13.54" (344mm) of precipitation.Snowfall
January through May, September through December are months with snowfall in Acton, Montana. September is the first month it typically snows in Acton. Throughout September, in the average 0.2 snowfall days, it receives 0.12" (3mm) of snow. In Acton, during the entire year, snow falls for 68.6 days and aggregates up to 32.56" (827mm) of snow.Daylight
In September, the average length of the day is 12h and 31min.On the first day of September in Acton, sunrise is at 6:36 am and sunset at 7:52 pm. On the last day of the month, sunrise is at 7:12 am and sunset at 6:56 pm MDT.
Sunshine
In September, the average sunshine in Acton is 10.3h.UV index
The average daily maximum UV index in September is 4. A UV Index value of 3 to 5 symbolizes a moderate health risk from unprotected exposure to Sun's UV rays for the ordinary person.Note: A typical high UV index of 4 in September suggests the following recommendations:
Take necessary precautions - Defending against sun damage is advocated. When the Sun's UV radiation is most intense during midday, it's best to find shade and limit exposure. Experience reduced UV exposure by about half when donning a wide-brim hat. Be aware! The reflective nature of snow can magnify the Sun's UV radiation almost twofold.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Acton, MT
- Average high temperature in September: 73.2°F
The warmest month (with the highest average high temperature) is July (85.5°F).
The month with the lowest average high temperature is December (31.1°F).
- Average low temperature in September: 52.5°F
The months with the highest average low temperature are July and August (60.6°F).
The coldest month (with the lowest average low temperature) is February (18.3°F).
Average pressure in September
Acton, 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 (29.86"Hg).
Average wind speed in September
Acton, MT
- Average wind speed in September: 8.1mph
The windiest month (with the highest average wind speed) is January (9.9mph).
The calmest month (with the lowest average wind speed) is July (7.1mph).
Average humidity in September
Acton, MT
- Average humidity in September: 44%
The month with the highest relative humidity is January (76%).
The month with the lowest relative humidity is August (40%).
Average rainfall in September
Acton, MT
- Average rainfall in September: 0.67"
The wettest month (with the highest rainfall) is May (2.24").
The driest month (with the least rainfall) is July (0.43").
Average rainfall days in September
Acton, MT
- Average rainfall days in September: 6.8 days
The month with the highest number of rainy days is May (17.8 days).
The month with the least rainy days is January (5.6 days).
Average snowfall in September
Acton, MT
- Average snowfall in September: 0.12"
The month with the highest snowfall is February (6.61").
The months with the least snowfall are June, July and August (0").
Average snowfall days in September
Acton, MT
- Average snowfall days in September: 0.2 days
The month with the highest number of snowfall days is February (14.3 days).
The months with the least snowfall days are June, July and August (0 days).
Average daylight in September /
Average sunshine in September
Acton, 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 18min
The month with the most sunshine is July (Average sunshine: 11h and 54min).
The month with the least sunshine is February (Average sunshine: 5h and 18min).
Average sunshine days in September
Acton, MT
- Average sunshine days in September: 21.1 days
The month with the most sunshine days is September (21.1 days).
The month with the least sunshine days is April (9.8 days).
Average UV index in September
Acton, MT
- Average UV index in September: 4
The month with the highest UV index is July (UV index 7).
The months with the lowest UV index are January, February, March, November and December (UV index 2).
Average cloud cover in September
Acton, MT
- Average cloud cover in September: 20
The month with the most cloud cover is February (Cloud cover 46).
The month with the least cloud cover is July (Cloud cover 14).
Average visibility in September
Acton, 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).
