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
September's arrival signals a moderate reduction in the average high-temperature, easing from a moderate 57.6°F (14.2°C) in August to a frosty 48.7°F (9.3°C). Nightly temperatures drop to an average low of 36.5°F (2.5°C) in September.Humidity
In Butte, the average relative humidity in September is 77%.Rainfall
September is the month with the most rainfall. Rain falls for 20.6 days and accumulates 2.24" (57mm) 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 0.08" (2mm) of snow. Throughout the year, there are 76.2 snowfall days, and 33.5" (851mm) of snow is accumulated.Daylight
In Butte, the average length of the day in September is 12h and 52min.On the first day of September, sunrise is at 6:49 am and sunset at 9:02 pm. On the last day of the month, sunrise is at 8:02 am and sunset at 7:28 pm AKDT.
Sunshine
In Butte, the average sunshine in September is 8.1h.UV index
The average daily maximum UV index in September in Butte is 2. A UV Index of 2, and less, symbolizes a minimal health vulnerability from exposure to the Sun's UV rays for ordinary individuals.Note: The daily high UV index of 2 in September translates into this advice:
Apart from children, who require continuous protection, most can endure sun exposure for up to an hour without experiencing burns. Protect yourself from the midday Sun's peak UV radiation by minimizing exposure. Limit sun-induced ocular harm with sunglasses that feature UVA and UVB filtration. Stay alert! Snow's reflective properties can almost double the UV radiation from the Sun.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
What are September temperatures?
What is the average humidity in September?
What is the rainiest month?
How much does it rain in September?
When does it start to snow?
How many hours of daylight does Butte have in September?
When is the sunrise / sunset in September?
How long on average sun shines in September?
What is the UV index reading in September?
Average temperature in September
Butte, AK
- Average high temperature in September: 48.7°F
The warmest month (with the highest average high temperature) is July (61.2°F).
The month with the lowest average high temperature is January (18.1°F).
- Average low temperature in September: 36.5°F
The month with the highest average low temperature is July (44.2°F).
The coldest month (with the lowest average low temperature) is January (8.1°F).
Average pressure in September
Butte, AK
- Average pressure in September: 29.75"Hg
The month with the highest atmospheric pressure is July (29.96"Hg).
The months with the lowest atmospheric pressure are November and December (29.7"Hg).
Average wind speed in September
Butte, AK
- Average wind speed in September: 4.3mph
The windiest month (with the highest average wind speed) is January (5.5mph).
The calmest month (with the lowest average wind speed) is July (4mph).
Average humidity in September
Butte, AK
- Average humidity in September: 77%
The month with the highest relative humidity is March (87%).
The months with the lowest relative humidity are May and June (69%).
Average rainfall in September
Butte, AK
- Average rainfall in September: 2.24"
The wettest month (with the highest rainfall) is September (2.24").
The driest month (with the least rainfall) is January (0.91").
Average rainfall days in September
Butte, AK
- Average rainfall days in September: 20.6 days
The month with the highest number of rainy days is June (22.4 days).
The month with the least rainy days is February (8.9 days).
Average snowfall in September
Butte, AK
- Average snowfall in September: 0.08"
The month with the highest snowfall is February (6.93").
The months with the least snowfall are June, July and August (0").
Average snowfall days in September
Butte, AK
- Average snowfall days in September: 0.2 days
The month with the highest number of snowfall days is February (14.1 days).
The months with the least snowfall days are June, July and August (0 days).
Average daylight in September /
Average sunshine in September
Butte, AK
- Average daylight in September: 12h and 5min
The month with the longest days is June (Average daylight: 19h and 24min).
The month with the shortest days is December (Average daylight: 5h and 30min).
- Average sunshine in September: 8h and 1min
The month with the most sunshine is May (Average sunshine: 11h and 48min).
The month with the least sunshine is December (Average sunshine: 3h and 54min).
Average sunshine days in September
Butte, AK
- Average sunshine days in September: 7.5 days
The month with the most sunshine days is January (13.9 days).
The month with the least sunshine days is June (5.3 days).
Average UV index in September
Butte, AK
- Average UV index in September: 2
The months with the highest UV index are June and July (UV index 4).
The months with the lowest UV index are January and December (UV index 1).
Average cloud cover in September
Butte, AK
- Average cloud cover in September: 42
The month with the most cloud cover is April (Cloud cover 46).
The month with the least cloud cover is January (Cloud cover 37).
Average visibility in September
Butte, AK
- Average visibility in September: 6mi
The months with the highest visibility are May, June, July, August, September, October and November (6mi).
The months with the lowest visibility are February, March and April (4mi).
Butte, Alaska, USA
Weather forecast for your location
2. Allow the app to use your location