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
Observing a mild shift, the average high-temperature during September reduces from August's 85.1°F (29.5°C) to a still moderately hot 75.2°F (24°C). Throughout the September nights, Pompeys Pillar encounters a low-temperature of 54.7°F (12.6°C).Humidity
In Pompeys Pillar, the average relative humidity in September is 42%.Rainfall
In Pompeys Pillar, during September, the rain falls for 6.7 days and regularly aggregates up to 1.06" (27mm) of precipitation. Throughout the year, there are 103 rainfall days, and 11.97" (304mm) of precipitation is accumulated.Snowfall
January through May, September through December are months with snowfall. September is the first month it typically snows. Throughout September, in the average 0.1 snowfall days, it receives 0.08" (2mm) of snow. Throughout the year, there are 56.7 snowfall days, and 25.16" (639mm) of snow is accumulated.Daylight
The average length of the day in September is 12h and 31min.On the first day of the month, sunrise is at 6:33 am and sunset at 7:49 pm. On the last day of September, sunrise is at 7:10 am and sunset at 6:53 pm MDT.
Sunshine
In September, the average sunshine is 10.6h.UV index
In Pompeys Pillar, the average daily maximum UV index in September is 5. A UV Index value of 3 to 5 symbolizes a moderate health risk from unsafe exposure to UV radiation for the ordinary person.Note: In September, the maximum UV index of 5 suggests these recommendations:
Make use of precautions - It is urged to ward off sun damage. Exposing oneself to the midday Sun can be harmful due to the strong UV radiation; limit your time outside. For optimum UV protection, wear sun-resistant attire complemented with a hat and quality shades. Be careful! The Sun's UV radiation can nearly be doubled by the reflective quality of snow.
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?
How many hours of daylight does Pompeys Pillar have in September?
When is the sunrise / sunset in September?
How many hours of sunshine does Pompeys Pillar have in September?
What is the UV index reading in September?
Average temperature in September
Pompeys Pillar, MT
- Average high temperature in September: 75.2°F
The warmest month (with the highest average high temperature) is July (87.3°F).
The month with the lowest average high temperature is December (31.3°F).
- Average low temperature in September: 54.7°F
The month with the highest average low temperature is July (62.8°F).
The coldest month (with the lowest average low temperature) is January (17.8°F).
Average pressure in September
Pompeys Pillar, MT
- Average pressure in September: 29.93"Hg
The month with the highest atmospheric pressure is January (30.13"Hg).
The month with the lowest atmospheric pressure is June (29.85"Hg).
Average wind speed in September
Pompeys Pillar, MT
- Average wind speed in September: 8mph
The windiest month (with the highest average wind speed) is April (9.1mph).
The calmest month (with the lowest average wind speed) is July (7.3mph).
Average humidity in September
Pompeys Pillar, MT
- Average humidity in September: 42%
The month with the highest relative humidity is January (78%).
The month with the lowest relative humidity is August (38%).
Average rainfall in September
Pompeys Pillar, MT
- Average rainfall in September: 1.06"
The wettest month (with the highest rainfall) is May (1.81").
The driest month (with the least rainfall) is August (0.63").
Average rainfall days in September
Pompeys Pillar, MT
- Average rainfall days in September: 6.7 days
The month with the highest number of rainy days is May (13.6 days).
The month with the least rainy days is December (5.9 days).
Average snowfall in September
Pompeys Pillar, MT
- Average snowfall in September: 0.08"
The month with the highest snowfall is February (5.43").
The months with the least snowfall are June, July and August (0").
Average snowfall days in September
Pompeys Pillar, MT
- Average snowfall days in September: 0.1 days
The month with the highest number of snowfall days is February (12.5 days).
The months with the least snowfall days are June, July and August (0 days).
Average daylight in September /
Average sunshine in September
Pompeys Pillar, 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: 10h and 4min
The month with the most sunshine is July (Average sunshine: 11h and 54min).
The month with the least sunshine is February (Average sunshine: 5h and 36min).
Average sunshine days in September
Pompeys Pillar, MT
- Average sunshine days in September: 21.5 days
The month with the most sunshine days is September (21.5 days).
The month with the least sunshine days is February (13.3 days).
Average UV index in September
Pompeys Pillar, MT
- Average UV index in September: 5
The month with the highest UV index is July (UV index 7).
The months with the lowest UV index are January, February, March, November and December (UV index 2).
Average cloud cover in September
Pompeys Pillar, MT
- Average cloud cover in September: 19
The month with the most cloud cover is February (Cloud cover 43).
The month with the least cloud cover is July (Cloud cover 13).
Average visibility in September
Pompeys Pillar, 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).
Pompeys Pillar, Montana, USA
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