September weather forecastBynum, MT
September
Weather in September
The first month of the autumn, September, is still a pleasant month in Bynum, Montana, with an average temperature ranging between max 68.2°F (20.1°C) and min 48.6°F (9.2°C).Temperature
As August shifts into September, a slight alteration in temperatures is observed, with average highs reducing from a moderately hot 79°F (26.1°C) to an agreeable 68.2°F (20.1°C). Bynum, in September, experiences an average temperature of 48.6°F (9.2°C) at night.Humidity
In September, the average relative humidity is 48%.Rainfall
In Bynum, during September, the rain falls for 6.1 days and regularly aggregates up to 0.79" (20mm) of precipitation. In Bynum, during the entire year, the rain falls for 73.3 days and collects up to 9.17" (233mm) of precipitation.Snowfall
Months with snowfall are January through May, September through December. September is the first month it typically snows. Throughout September, in the average 0.7 snowfall days, it receives 0.55" (14mm) of snow. In Bynum, during the entire year, snow falls for 50.3 days and aggregates up to 21.26" (540mm) of snow.Daylight
In Bynum, the average length of the day in September is 12h and 33min.On the first day of the month, sunrise is at 6:48 am and sunset at 8:09 pm. On the last day of September, sunrise is at 7:28 am and sunset at 7:09 pm MDT.
Sunshine
In September, the average sunshine is 9.7h.UV index
In September, the average daily maximum UV index is 4. A UV Index of 3 to 5 symbolizes a medium vulnerability from exposure to the Sun's UV radiation for ordinary individuals.Note: In September, the maximum UV index of 4 suggests this advice:
Put precautions into practice - Guidance to elude sunburn is provided. Avoiding the Sun during its peak radiation time around midday is a healthy practice. Wearing a wide-brim hat can block approximately 50% of UV radiation, protecting the eyes. Take note! UV radiation from the Sun can double in intensity due to snow reflection.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Bynum, MT
- Average high temperature in September: 68.2°F
The warmest month (with the highest average high temperature) is July (79.7°F).
The month with the lowest average high temperature is December (28.8°F).
- Average low temperature in September: 48.6°F
The month with the highest average low temperature is August (55.9°F).
The coldest month (with the lowest average low temperature) is December (16.2°F).
Average pressure in September
Bynum, MT
- Average pressure in September: 29.96"Hg
The month with the highest atmospheric pressure is January (30.14"Hg).
The month with the lowest atmospheric pressure is June (29.88"Hg).
Average wind speed in September
Bynum, MT
- Average wind speed in September: 8.8mph
The windiest month (with the highest average wind speed) is January (11.2mph).
The calmest months (with the lowest average wind speed) are July and August (8mph).
Average humidity in September
Bynum, MT
- Average humidity in September: 48%
The month with the highest relative humidity is January (76%).
The month with the lowest relative humidity is August (42%).
Average rainfall in September
Bynum, MT
- Average rainfall in September: 0.79"
The wettest month (with the highest rainfall) is June (1.93").
The driest month (with the least rainfall) is December (0.35").
Average rainfall days in September
Bynum, MT
- Average rainfall days in September: 6.1 days
The month with the highest number of rainy days is May (11.3 days).
The month with the least rainy days is November (2.7 days).
Average snowfall in September
Bynum, MT
- Average snowfall in September: 0.55"
The month with the highest snowfall is February (4.17").
The months with the least snowfall are June, July and August (0").
Average snowfall days in September
Bynum, MT
- Average snowfall days in September: 0.7 days
The month with the highest number of snowfall days is February (11.3 days).
The months with the least snowfall days are July and August (0 days).
Average daylight in September /
Average sunshine in September
Bynum, MT
- Average daylight in September: 12h and 36min
The month with the longest days is June (Average daylight: 16h and 0min).
The month with the shortest days is December (Average daylight: 8h and 30min).
- Average sunshine in September: 9h and 42min
The month with the most sunshine is July (Average sunshine: 12h and 6min).
The month with the least sunshine is December (Average sunshine: 5h and 48min).
Average sunshine days in September
Bynum, MT
- Average sunshine days in September: 21 days
The month with the most sunshine days is October (23.2 days).
The month with the least sunshine days is February (15.8 days).
Average UV index in September
Bynum, 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, October, November and December (UV index 2).
Average cloud cover in September
Bynum, MT
- Average cloud cover in September: 22
The month with the most cloud cover is February (Cloud cover 41).
The month with the least cloud cover is July (Cloud cover 14).
Average visibility in September
Bynum, 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).





