Contents
- Weather in September
- Frequently asked questions
- Average temperature in September
- Average pressure in September
- Average wind speed in September
- Average humidity in September
- Average rainfall in September
- Average rainfall days in September
- Average snowfall in September
- Average snowfall days in September
- Average daylight in September
- Average sunshine in September
- Average sunshine days in September
- Average UV index in September
- Average cloud cover in September
- Average visibility in September
Weather in September
Temperature
Butte in September demonstrates a small temperature transition, adjusting from an average high of a warm 74.8°F (23.8°C) in August to a comfortable 64.9°F (18.3°C). Throughout September, Butte notes a dramatic plunge from the daily high to an average low-temperature of 40.1°F (4.5°C).Humidity
In Butte, the average relative humidity in September is 54%.Rainfall
In Butte, during September, the rain falls for 8.5 days and regularly aggregates up to 1.06" (27mm) of precipitation. In Butte, during the entire year, the rain falls for 102.5 days and collects up to 13.74" (349mm) of precipitation.Snowfall
January through June, September through December are months with snowfall. September is the first month it typically snows. Throughout September, in the average 1.1 snowfall days, it receives 1.65" (42mm) of snow. Throughout the year, there are 103.1 snowfall days, and 52.56" (1335mm) of snow is accumulated.Daylight
In Butte, the average length of the day in September is 12h and 31min.On the first day of September, sunrise is at 6:51 am and sunset at 8:07 pm. On the last day of the month, sunrise is at 7:28 am and sunset at 7:11 pm MDT.
Sunshine
In Butte, the average sunshine in September is 9.5h.UV index
The average daily maximum UV index in September is 3. A UV Index estimate of 3 to 5 represents a moderate health risk from exposure to the Sun's UV rays for the average person.Note: The maximum UV index, 3 during September, leads to the following recommendations:
Exercise caution. Those with pale skin may experience burns in less than half an hour. Midday Sun has the strongest UV rays, making it crucial to limit exposure and find shade. Your best bet for sun defense on the face, eyes, and neck is a hat with a wide brim. Consider this! The reflection from snow can almost double the intensity of the Sun's UV radiation.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
What is the average September temperature?
What is the average humidity in September?
How much does it rain in September?
When does it start to snow?
What is the average length of the day in September?
What time are sunrise and sunset in September?
How long on average sun shines in September?
What is the UV index reading in September?
Average temperature in September
Butte, MT
- Average high temperature in September: 64.9°F
The warmest month (with the highest average high temperature) is July (76.5°F).
The month with the lowest average high temperature is December (25.2°F).
- Average low temperature in September: 40.1°F
The month with the highest average low temperature is July (46.9°F).
The coldest month (with the lowest average low temperature) is December (9°F).
Average pressure in September
Butte, MT
- Average pressure in September: 29.99"Hg
The month with the highest atmospheric pressure is January (30.21"Hg).
The month with the lowest atmospheric pressure is June (29.92"Hg).
Average wind speed in September
Butte, MT
- Average wind speed in September: 5.6mph
The windiest month (with the highest average wind speed) is April (6.6mph).
The calmest month (with the lowest average wind speed) is August (5mph).
Average humidity in September
Butte, MT
- Average humidity in September: 54%
The months with the highest relative humidity are January, February and December (87%).
The month with the lowest relative humidity is July (48%).
Average rainfall in September
Butte, MT
- Average rainfall in September: 1.06"
The wettest month (with the highest rainfall) is May (2.24").
The driest months (with the least rainfall) are January, November and December (0.67").
Average rainfall days in September
Butte, MT
- Average rainfall days in September: 8.5 days
The month with the highest number of rainy days is May (15.9 days).
The month with the least rainy days is November (4.1 days).
Average snowfall in September
Butte, MT
- Average snowfall in September: 1.65"
The month with the highest snowfall is March (8.74").
The months with the least snowfall are July and August (0").
Average snowfall days in September
Butte, MT
- Average snowfall days in September: 1.1 days
The month with the highest number of snowfall days is February (17.7 days).
The months with the least snowfall days are July and August (0 days).
Average daylight in September /
Average sunshine in September
Butte, MT
- Average daylight in September: 12h and 3min
The month with the longest days is June (Average daylight: 15h and 42min).
The month with the shortest days is December (Average daylight: 8h and 42min).
- Average sunshine in September: 9h and 3min
The month with the most sunshine is July (Average sunshine: 11h and 30min).
The month with the least sunshine is December (Average sunshine: 5h and 18min).
Average sunshine days in September
Butte, MT
- Average sunshine days in September: 18.9 days
The month with the most sunshine days is August (19.1 days).
The month with the least sunshine days is April (9.8 days).
Average UV index in September
Butte, MT
- Average UV index in September: 3
The month with the highest UV index is July (UV index 5).
The month with the lowest UV index is February (UV index 1).
Average cloud cover in September
Butte, MT
- Average cloud cover in September: 23
The month with the most cloud cover is February (Cloud cover 54).
The month with the least cloud cover is August (Cloud cover 16).
Average visibility in September
Butte, 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 and December (4mi).
Butte, Montana, USA
Weather forecast for your location
2. Allow the app to use your location