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 in Butte comes with a decrease in the average high-temperature, moving from a moderately hot 74.8°F (23.8°C) in August to a refreshing 64.9°F (18.3°C). Butte records a pronounced decline from the day's peak to an average nighttime low-temperature of 40.1°F (4.5°C) throughout September.Humidity
In September, the average relative humidity is 54%.Rainfall
In Butte, in September, during 8.5 rainfall days, 1.06" (27mm) of precipitation is typically accumulated. In Butte, during the entire year, the rain falls for 102.5 days and collects up to 13.74" (349mm) of precipitation.Snowfall
Months with snowfall in Butte are January through June, September through December. 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
The average length of the day in September in Butte is 12h and 31min.On the first day of the month, sunrise is at 6:51 am and sunset at 8:07 pm. On the last day of September, in Butte, sunrise is at 7:28 am and sunset at 7:11 pm MDT.
Sunshine
The average sunshine in September in Butte, Montana, 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 medium vulnerability from exposure to the Sun's UV rays for ordinary individuals.Note: The maximum UV index of 3 during September translates into these guidelines:
Safety measures are advised. Light-skinned individuals may experience burns in under half an hour. For health reasons, it's advisable to reduce direct sun exposure during peak hours around midday. Protect your eyes, ears, face, and neck from the Sun by wearing a wide-brimmed hat. Heads up! The UV radiation from the Sun can almost be doubled by snow reflection.
Frequently asked questions
What is the temperature in September in Butte?
What is the average humidity in September in Butte?
How many days does it rain in September in Butte?
When does it start snowing in Butte?
What is the average length of the day in September in Butte?
When are sunrise and sunset in September in Butte?
How many hours of sunshine does Butte have in September?
How high is the UV index in September in Butte?
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
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