September weather forecastCircle, MT
September
Weather in September
September, the first month of the autumn in Circle, is still a pleasant month, with temperature in the range of an average low of 54.5°F (12.5°C) and an average high of 73°F (22.8°C).Temperature
The decrease of average high-temperatures is mild in September, with a decline from a warm 83.3°F (28.5°C) in August to an agreeable 73°F (22.8°C). Throughout September, Circle registers a consistent average low-temperature of 54.5°F (12.5°C).Humidity
In September, the average relative humidity in Circle is 46%.Rainfall
In Circle, in September, during 8.3 rainfall days, 1.73" (44mm) of precipitation is typically accumulated. Throughout the year, in Circle, there are 102.6 rainfall days, and 13.35" (339mm) of precipitation is accumulated.Snowfall
In Circle, Montana, snow does not fall in June through September.Daylight
The average length of the day in September in Circle is 12h and 33min.On the first day of September, sunrise is at 6:22 am and sunset at 7:41 pm. On the last day of the month, sunrise is at 7:01 am and sunset at 6:43 pm MDT.
Sunshine
The average sunshine in September is 10.2h.UV index
In Circle, 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 ordinary individuals.Note: In September, the UV index of 4 transforms into the following advice:
Prioritize safety - Suggestions to prevent sun damage are offered. Around midday, solar radiation is most harmful; hence, exposure should be limited. During bright days, sunglasses that offer UVA and UVB defense are recommended.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Circle, MT
- Average high temperature in September: 73°F
The warmest month (with the highest average high temperature) is July (84.7°F).
The month with the lowest average high temperature is January (25.5°F).
- Average low temperature in September: 54.5°F
The month with the highest average low temperature is July (64°F).
The coldest month (with the lowest average low temperature) is January (12.6°F).
Average pressure in September
Circle, MT
- Average pressure in September: 29.92"Hg
The month with the highest atmospheric pressure is February (30.16"Hg).
The month with the lowest atmospheric pressure is June (29.83"Hg).
Average wind speed in September
Circle, MT
- Average wind speed in September: 10.3mph
The windiest month (with the highest average wind speed) is April (11.2mph).
The calmest month (with the lowest average wind speed) is August (9.3mph).
Average humidity in September
Circle, MT
- Average humidity in September: 46%
The month with the highest relative humidity is January (85%).
The month with the lowest relative humidity is August (43%).
Average rainfall in September
Circle, MT
- Average rainfall in September: 1.73"
The wettest month (with the highest rainfall) is May (2.2").
The driest month (with the least rainfall) is January (0.51").
Average rainfall days in September
Circle, MT
- Average rainfall days in September: 8.3 days
The month with the highest number of rainy days is May (13.7 days).
The month with the least rainy days is February (4 days).
Average snowfall in September
Circle, MT
- Average snowfall in September: 0"
The month with the highest snowfall is February (3.62").
The months with the least snowfall are June, July, August and September (0").
Average snowfall days in September
Circle, MT
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is January (12.9 days).
The months with the least snowfall days are July, August and September (0 days).
Average daylight in September /
Average sunshine in September
Circle, 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 30min).
- Average sunshine in September: 10h and 12min
The month with the most sunshine is July (Average sunshine: 11h and 42min).
The months with the least sunshine are February and December (Average sunshine: 4h and 54min).
Average sunshine days in September
Circle, MT
- Average sunshine days in September: 19.8 days
The month with the most sunshine days is September (19.8 days).
The month with the least sunshine days is June (13.1 days).
Average UV index in September
Circle, 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 November and December (UV index 1).
Average cloud cover in September
Circle, MT
- Average cloud cover in September: 22
The month with the most cloud cover is February (Cloud cover 49).
The months with the least cloud cover are July and August (Cloud cover 17).
Average visibility in September
Circle, 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).





