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 suggests a modest reduction in the average high-temperature, shifting from a warm 78.6°F (25.9°C) in August to a comfortable 67.6°F (19.8°C). Big Arm registers a prominent dip from daytime highs, with an average of 42.3°F (5.7°C) during the nights of September.Humidity
In Big Arm, the average relative humidity in September is 59%.Rainfall
In September, the rain falls for 10.7 days. Throughout September, 0.94" (24mm) of precipitation is accumulated. Throughout the year, there are 160.2 rainfall days, and 18.11" (460mm) of precipitation is accumulated.Snowfall
Months with snowfall are January through May, September through December. September is the first month it typically snows. Throughout September, in the average 0.2 snowfall days, it receives 0.31" (8mm) of snow. Throughout the year, there are 99 snowfall days, and 47.28" (1201mm) of snow is accumulated.Daylight
The average length of the day in September in Big Arm is 12h and 33min.On the first day of the month, sunrise is at 6:56 am and sunset at 8:17 pm. On the last day of September, sunrise is at 7:36 am and sunset at 7:17 pm MDT.
Sunshine
In September, the average sunshine in Big Arm is 9.4h.UV index
In Big Arm, the average daily maximum UV index in September is 3. A UV Index value of 3 to 5 symbolizes a moderate health risk from exposure to the Sun's UV rays for the average person.Note: In September, the maximum UV index of 3 translates into these guidelines:
Put precautions into practice - Protective measures against sun-induced damage are advised. Direct Sun exposure should be minimized especially during midday when radiation is most intense. A wide-brimmed hat is a staple for defending the face, eyes, ears, and neck from the Sun. Mark this! Snow reflection can nearly double the UV radiation intensity from the Sun.
Frequently asked questions
What is the average September temperature in Big Arm?
What is the average humidity in September in Big Arm?
How much does it rain in Big Arm in September?
When does it start to snow in Big Arm?
What is the average length of the day in September in Big Arm?
What time are sunrise and sunset in September in Big Arm?
How long on average sun shines in September in Big Arm?
How high is the UV index in September in Big Arm?
Average temperature in September
Big Arm, MT
- Average high temperature in September: 67.6°F
The warmest month (with the highest average high temperature) is July (79.3°F).
The month with the lowest average high temperature is December (27.9°F).
- Average low temperature in September: 42.3°F
The months with the highest average low temperature are July and August (48.9°F).
The coldest month (with the lowest average low temperature) is December (16.7°F).
Average pressure in September
Big Arm, MT
- Average pressure in September: 29.98"Hg
The month with the highest atmospheric pressure is January (30.17"Hg).
The month with the lowest atmospheric pressure is June (29.92"Hg).
Average wind speed in September
Big Arm, MT
- Average wind speed in September: 3.9mph
The windiest month (with the highest average wind speed) is April (4.8mph).
The calmest month (with the lowest average wind speed) is August (3.7mph).
Average humidity in September
Big Arm, MT
- Average humidity in September: 59%
The month with the highest relative humidity is January (91%).
The month with the lowest relative humidity is August (51%).
Average rainfall in September
Big Arm, MT
- Average rainfall in September: 0.94"
The wettest month (with the highest rainfall) is June (2.2").
The driest months (with the least rainfall) are July and August (0.55").
Average rainfall days in September
Big Arm, MT
- Average rainfall days in September: 10.7 days
The months with the highest number of rainy days are March and April (18.8 days).
The month with the least rainy days is August (7 days).
Average snowfall in September
Big Arm, MT
- Average snowfall in September: 0.31"
The month with the highest snowfall is February (10.28").
The months with the least snowfall are June, July and August (0").
Average snowfall days in September
Big Arm, MT
- Average snowfall days in September: 0.2 days
The month with the highest number of snowfall days is December (19.8 days).
The months with the least snowfall days are June, July and August (0 days).
Average daylight in September /
Average sunshine in September
Big Arm, MT
- Average daylight in September: 12h and 4min
The month with the longest days is June (Average daylight: 15h and 54min).
The month with the shortest days is December (Average daylight: 8h and 30min).
- Average sunshine in September: 9h and 2min
The month with the most sunshine is July (Average sunshine: 11h and 54min).
The month with the least sunshine is January (Average sunshine: 4h and 30min).
Average sunshine days in September
Big Arm, MT
- Average sunshine days in September: 17.5 days
The month with the most sunshine days is July (21.3 days).
The month with the least sunshine days is March (6.4 days).
Average UV index in September
Big Arm, MT
- Average UV index in September: 3
The months with the highest UV index are June and July (UV index 5).
The months with the lowest UV index are January, February, November and December (UV index 1).
Average cloud cover in September
Big Arm, MT
- Average cloud cover in September: 22
The month with the most cloud cover is January (Cloud cover 54).
The months with the least cloud cover are July and August (Cloud cover 14).
Average visibility in September
Big Arm, MT
- Average visibility in September: 6mi
The months with the highest visibility are April, May, June, July, August, September and October (6mi).
The months with the lowest visibility are January, February and December (4mi).
Big Arm, Montana, USA
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