September weather forecastArlee, MT
September
Weather in September
September, the first month of the autumn in Arlee, is still a refreshing month, with an average temperature fluctuating between 40.8°F (4.9°C) and 67.8°F (19.9°C).Temperature
Arlee experiences a temperature shift at the start of September, with average high-temperatures adjusting from a moderately hot 78.3°F (25.7°C) in August to a refreshing 67.8°F (19.9°C). The average low-temperature reading in September for Arlee reflects a significant fall from the daytime highs, stabilizing at a wintry 40.8°F (4.9°C).Humidity
In September, the average relative humidity is 59%.Rainfall
In Arlee, in September, it is raining for 8.4 days, with typically 0.83" (21mm) of accumulated precipitation. Throughout the year, there are 92.3 rainfall days, and 14.37" (365mm) of precipitation is accumulated.Snowfall
Months with snowfall are January through June, September through December. September is the first month it typically snows in Arlee. Throughout September, in the average 0.7 snowfall days, it receives 0.47" (12mm) of snow. Throughout the year, there are 121.1 snowfall days, and 68.31" (1735mm) of snow is accumulated.Daylight
In Arlee, the average length of the day in September is 12h and 32min.On the first day of September in Arlee, sunrise is at 6:56 am and sunset at 8:15 pm. On the last day of the month, sunrise is at 7:34 am and sunset at 7:17 pm MDT.
Sunshine
In September, the average sunshine is 9h.UV index
The average daily maximum UV index in September in Arlee is 3. A UV Index reading of 3 to 5 represents a medium vulnerability from exposure to the Sun's UV rays for average individuals.Note: A daily high UV index of 3 in September leads to these guidelines:
Take necessary precautions - Protection from skin and eye injury is mandatory. Protect yourself from the midday Sun's peak UV radiation by minimizing exposure. Boost your sun resistance with garments that are densely woven yet spacious. Keep in mind! Snow's reflective quality can nearly 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
Arlee, MT
- Average high temperature in September: 67.8°F
The warmest month (with the highest average high temperature) is July (78.8°F).
The month with the lowest average high temperature is December (27°F).
- Average low temperature in September: 40.8°F
The month with the highest average low temperature is August (47.5°F).
The coldest month (with the lowest average low temperature) is December (14.4°F).
Average pressure in September
Arlee, MT
- Average pressure in September: 29.98"Hg
The month with the highest atmospheric pressure is January (30.19"Hg).
The month with the lowest atmospheric pressure is June (29.93"Hg).
Average wind speed in September
Arlee, MT
- Average wind speed in September: 4.2mph
The windiest month (with the highest average wind speed) is April (5mph).
The calmest month (with the lowest average wind speed) is August (4.1mph).
Average humidity in September
Arlee, MT
- Average humidity in September: 59%
The month with the highest relative humidity is January (91%).
The months with the lowest relative humidity are July and August (51%).
Average rainfall in September
Arlee, MT
- Average rainfall in September: 0.83"
The wettest month (with the highest rainfall) is April (1.61").
The driest month (with the least rainfall) is July (0.55").
Average rainfall days in September
Arlee, MT
- Average rainfall days in September: 8.4 days
The month with the highest number of rainy days is June (12.1 days).
The month with the least rainy days is February (4.5 days).
Average snowfall in September
Arlee, MT
- Average snowfall in September: 0.47"
The month with the highest snowfall is February (11.77").
The months with the least snowfall are July and August (0").
Average snowfall days in September
Arlee, MT
- Average snowfall days in September: 0.7 days
The month with the highest number of snowfall days is March (19.4 days).
The months with the least snowfall days are July and August (0 days).
Average daylight in September /
Average sunshine in September
Arlee, 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 36min).
- Average sunshine in September: 9h and 0min
The month with the most sunshine is July (Average sunshine: 11h and 36min).
The month with the least sunshine is January (Average sunshine: 4h and 18min).
Average sunshine days in September
Arlee, MT
- Average sunshine days in September: 19.8 days
The month with the most sunshine days is July (22.5 days).
The month with the least sunshine days is March (9.3 days).
Average UV index in September
Arlee, MT
- Average UV index in September: 3
The month with the highest UV index is July (UV index 6).
The months with the lowest UV index are January, February, November and December (UV index 1).
Average cloud cover in September
Arlee, MT
- Average cloud cover in September: 26
The month with the most cloud cover is February (Cloud cover 60).
The months with the least cloud cover are July and August (Cloud cover 16).
Average visibility in September
Arlee, MT
- Average visibility in September: 6mi
The months with the highest visibility are May, June, July, August, September and October (6mi).
The months with the lowest visibility are January, February, March, November and December (4mi).
