September weather forecastRoberts, MT
September
Weather in September
The first month of the autumn, September, is still a pleasant month in Roberts, Montana, with an average temperature fluctuating between 72°F (22.2°C) and 50.2°F (10.1°C).Temperature
September brings a decrease in the average high-temperature, falling from August's moderately hot 81.1°F (27.3°C) to an agreeable 72°F (22.2°C). Roberts's nighttime temperature in September demonstrates a noticeable plunge to a cool 50.2°F (10.1°C).Humidity
The average relative humidity in September is 45%.Rainfall
In Roberts, Montana, during September, the rain falls for 6.9 days and regularly aggregates up to 0.79" (20mm) of precipitation. Throughout the year, there are 108.1 rainfall days, and 12.83" (326mm) of precipitation is accumulated.Snowfall
January through June, September through December are months with snowfall. September is the first month it typically snows. Throughout September, in the average 0.8 snowfall days, it receives 0.67" (17mm) of snow. Throughout the year, there are 61.5 snowfall days, and 41.77" (1061mm) of snow is accumulated.Daylight
In September, the average length of the day is 12h and 31min.On the first day of the month, sunrise is at 6:39 am and sunset at 7:53 pm. On the last day of September, sunrise is at 7:14 am and sunset at 6:58 pm MDT.
Sunshine
The average sunshine in September is 10.6h.UV index
The average daily maximum UV index in September in Roberts is 4. A UV Index of 3 to 5 symbolizes a medium vulnerability from exposure to the Sun's UV radiation for the ordinary person.Note: The maximum UV index of 4 during September translates into these guidelines:
Take precautions - Protection against sunburn is recommended. Avoiding the Sun's peak radiation during midday hours is essential for health and safety. Loose clothes with a tight weave are optimal for safeguarding yourself against the Sun's rays. Be prepared! The intensity of the Sun's UV radiation can be amplified nearly double due to snow reflection.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Roberts, MT
- Average high temperature in September: 72°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 (30.7°F).
- Average low temperature in September: 50.2°F
The months with the highest average low temperature are July and August (57.2°F).
The coldest month (with the lowest average low temperature) is February (16.7°F).
Average pressure in September
Roberts, 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
Roberts, MT
- Average wind speed in September: 6.9mph
The windiest month (with the highest average wind speed) is January (8.7mph).
The calmest month (with the lowest average wind speed) is August (6mph).
Average humidity in September
Roberts, 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
Roberts, MT
- Average rainfall in September: 0.79"
The wettest month (with the highest rainfall) is May (2.09").
The driest month (with the least rainfall) is January (0.51").
Average rainfall days in September
Roberts, MT
- Average rainfall days in September: 6.9 days
The month with the highest number of rainy days is May (16.3 days).
The month with the least rainy days is February (4 days).
Average snowfall in September
Roberts, MT
- Average snowfall in September: 0.67"
The month with the highest snowfall is February (6.81").
The months with the least snowfall are July and August (0").
Average snowfall days in September
Roberts, MT
- Average snowfall days in September: 0.8 days
The month with the highest number of snowfall days is February (10.8 days).
The months with the least snowfall days are July and August (0 days).
Average daylight in September /
Average sunshine in September
Roberts, MT
- Average daylight in September: 12h and 30min
The month with the longest days is June (Average daylight: 15h and 36min).
The month with the shortest days is December (Average daylight: 8h and 48min).
- Average sunshine in September: 10h and 36min
The month with the most sunshine is July (Average sunshine: 11h and 54min).
The month with the least sunshine is February (Average sunshine: 6h and 12min).
Average sunshine days in September
Roberts, MT
- Average sunshine days in September: 18.4 days
The month with the most sunshine days is December (19.7 days).
The month with the least sunshine days is May (10.5 days).
Average UV index in September
Roberts, 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
Roberts, MT
- Average cloud cover in September: 18
The month with the most cloud cover is February (Cloud cover 38).
The months with the least cloud cover are July and August (Cloud cover 15).
Average visibility in September
Roberts, 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).
