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
Start of September brings a shift in the average high-temperature, falling from August's moderately hot 75.7°F (24.3°C) to a refreshing 66°F (18.9°C). A sharp divergence from daytime highs is noted during the month of September, with the average nighttime temperature settling at a wintry 41.7°F (5.4°C).Humidity
In September, the average relative humidity is 50%.Rainfall
In Dillon, in September, during 9.7 rainfall days, 0.87" (22mm) of precipitation is typically accumulated. Throughout the year, there are 126.7 rainfall days, and 10.35" (263mm) of precipitation is accumulated.Snowfall
Months with snowfall are January through June, September through December. September is the first month it typically snows. Throughout September, in the average 1 snowfall days, it receives 1.34" (34mm) of snow. Throughout the year, there are 81.2 snowfall days, and 29.76" (756mm) of snow is accumulated.Daylight
The average length of the day in September is 12h and 31min.On the first day of September, sunrise is at 6:53 am and sunset at 8:07 pm. On the last day of the month, sunrise is at 7:28 am and sunset at 7:12 pm MDT.
Sunshine
In Dillon, the average sunshine in September is 9.8h.UV index
In September, the average daily maximum UV index is 3. A UV Index of 3 to 5 symbolizes a moderate threat to health from exposure to the Sun's UV radiation for the ordinary person.Note: In September, the average maximum UV index of 3 translates into the following recommendations:
Prioritize safety - Suggestions to prevent sun damage are offered. The Sun's most harmful UV rays are emitted around midday; avoid staying outdoors for long during this time. Loose clothes with a tight weave are optimal for safeguarding yourself against the Sun's rays. Note well! The intensity of the Sun's UV rays can be nearly doubled by snow reflection.
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 snowing?
How many hours of daylight does Dillon have in September?
When are sunrise and sunset in September?
How many hours of sunshine does Dillon have in September?
What is the UV index reading in September?
Average temperature in September
Dillon, MT
- Average high temperature in September: 66°F
The warmest month (with the highest average high temperature) is July (77.5°F).
The month with the lowest average high temperature is December (25.2°F).
- Average low temperature in September: 41.7°F
The month with the highest average low temperature is July (47.5°F).
The coldest month (with the lowest average low temperature) is December (10.6°F).
Average pressure in September
Dillon, MT
- Average pressure in September: 29.99"Hg
The month with the highest atmospheric pressure is January (30.24"Hg).
The month with the lowest atmospheric pressure is June (29.92"Hg).
Average wind speed in September
Dillon, MT
- Average wind speed in September: 5.2mph
The windiest month (with the highest average wind speed) is November (6.8mph).
The calmest month (with the lowest average wind speed) is August (4.8mph).
Average humidity in September
Dillon, MT
- Average humidity in September: 50%
The month with the highest relative humidity is February (86%).
The months with the lowest relative humidity are July and August (45%).
Average rainfall in September
Dillon, MT
- Average rainfall in September: 0.87"
The wettest month (with the highest rainfall) is June (1.5").
The driest month (with the least rainfall) is January (0.51").
Average rainfall days in September
Dillon, MT
- Average rainfall days in September: 9.7 days
The month with the highest number of rainy days is May (15.3 days).
The month with the least rainy days is February (7.7 days).
Average snowfall in September
Dillon, MT
- Average snowfall in September: 1.34"
The month with the highest snowfall is February (5.51").
The months with the least snowfall are July and August (0").
Average snowfall days in September
Dillon, MT
- Average snowfall days in September: 1 days
The month with the highest number of snowfall days is February (14.1 days).
The months with the least snowfall days are July and August (0 days).
Average daylight in September /
Average sunshine in September
Dillon, MT
- Average daylight in September: 12h and 3min
The month with the longest days is June (Average daylight: 15h and 36min).
The month with the shortest days is December (Average daylight: 8h and 48min).
- Average sunshine in September: 9h and 5min
The month with the most sunshine is July (Average sunshine: 12h and 0min).
The month with the least sunshine is December (Average sunshine: 6h and 6min).
Average sunshine days in September
Dillon, MT
- Average sunshine days in September: 16.5 days
The month with the most sunshine days is July (18.2 days).
The month with the least sunshine days is April (10.1 days).
Average UV index in September
Dillon, 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
Dillon, MT
- Average cloud cover in September: 18
The month with the most cloud cover is February (Cloud cover 42).
The months with the least cloud cover are July and August (Cloud cover 13).
Average visibility in September
Dillon, MT
- Average visibility in September: 6mi
The months with the highest visibility are March, April, May, June, July, August, September, October and November (6mi).
The months with the lowest visibility are January, February and December (5mi).
Dillon, Montana, USA
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