September weather forecastBirney, MT
September
Weather in September
September, the first month of the autumn in Birney, is also a moderately hot month, with an average temperature fluctuating between 74.1°F (23.4°C) and 52.7°F (11.5°C).Temperature
The transition into September indicates a reduction in the average high-temperature, down to a still warm 74.1°F (23.4°C) from August's 83.7°F (28.7°C). During September, the temperature tends to dip to an average of 52.7°F (11.5°C) at night.Humidity
In Birney, the average relative humidity in September is 44%.Rainfall
In Birney, during September, the rain falls for 8.6 days and regularly aggregates up to 0.83" (21mm) of precipitation. In Birney, during the entire year, the rain falls for 127.6 days and collects up to 14.25" (362mm) of precipitation.Snowfall
January through May, September through December are months with snowfall. September is the first month it typically snows. Throughout September, in the average 0.2 snowfall days, it receives 0.12" (3mm) of snow. In Birney, during the entire year, snow falls for 65.3 days and aggregates up to 28.82" (732mm) of snow.Daylight
In September, the average length of the day is 12h and 31min.On the first day of September, sunrise is at 6:28 am and sunset at 7:42 pm. On the last day of the month, sunrise is at 7:03 am and sunset at 6:47 pm MDT.
Sunshine
In Birney, the average sunshine in September is 10.8h.UV index
The average daily maximum UV index in September is 4. A UV Index estimate of 3 to 5 represents a medium health hazard from unsafe exposure to UV radiation for the ordinary person.Note: In September, the maximum UV index of 4 transforms into these recommendations:
Take precautions - Protection against skin and eye damage is obliged. For skin protection, it's recommended to minimize Sun exposure during its peak hours around midday. In bright sunlight, prioritize sunglasses that grant protection from UVA and UVB radiation. Be attentive! The reflective property of snow can nearly double the Sun's UV radiation.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Birney, MT
- Average high temperature in September: 74.1°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: 52.7°F
The month with the highest average low temperature is July (61.5°F).
The coldest months (with the lowest average low temperature) are January and February (16.2°F).
Average pressure in September
Birney, MT
- Average pressure in September: 29.93"Hg
The month with the highest atmospheric pressure is January (30.13"Hg).
The month with the lowest atmospheric pressure is June (29.85"Hg).
Average wind speed in September
Birney, MT
- Average wind speed in September: 7.6mph
The windiest month (with the highest average wind speed) is April (9.1mph).
The calmest months (with the lowest average wind speed) are July and December (6.8mph).
Average humidity in September
Birney, MT
- Average humidity in September: 44%
The months with the highest relative humidity are January and February (79%).
The month with the lowest relative humidity is August (40%).
Average rainfall in September
Birney, MT
- Average rainfall in September: 0.83"
The wettest month (with the highest rainfall) is May (2.64").
The driest month (with the least rainfall) is December (0.67").
Average rainfall days in September
Birney, MT
- Average rainfall days in September: 8.6 days
The month with the highest number of rainy days is May (18 days).
The month with the least rainy days is January (6.3 days).
Average snowfall in September
Birney, MT
- Average snowfall in September: 0.12"
The month with the highest snowfall is February (5.2").
The months with the least snowfall are June, July and August (0").
Average snowfall days in September
Birney, 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
Birney, 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 48min
The months with the most sunshine are July and August (Average sunshine: 11h and 54min).
The month with the least sunshine is February (Average sunshine: 5h and 42min).
Average sunshine days in September
Birney, MT
- Average sunshine days in September: 18.2 days
The month with the most sunshine days is September (18.2 days).
The month with the least sunshine days is May (9.6 days).
Average UV index in September
Birney, 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
Birney, MT
- Average cloud cover in September: 18
The month with the most cloud cover is February (Cloud cover 41).
The months with the least cloud cover are July and August (Cloud cover 14).
Average visibility in September
Birney, 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).
