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
The shift from August to September involves a decrease in the average high-temperature, dropping from a warm 81.1°F (27.3°C) to an agreeable 70.5°F (21.4°C). Throughout the month of September, the average temperature dips to a frosty 49.5°F (9.7°C) at night.Humidity
In Sun River, the average relative humidity in September is 47%.Rainfall
In September, in Sun River, the rain falls for 8.7 days. Throughout September, 1.14" (29mm) of precipitation is accumulated. In Sun River, during the entire year, the rain falls for 112.8 days and collects up to 12.95" (329mm) of precipitation.Snowfall
Months with snowfall in Sun River are January through May, September through December. September is the first month it typically snows in Sun River. Throughout September, in the average 0.7 snowfall days, it receives 2.05" (52mm) of snow. Throughout the year, in Sun River, there are 69.4 snowfall days, and 35.35" (898mm) of snow is accumulated.Daylight
In Sun River, the average length of the day in September is 12h and 33min.On the first day of the month, sunrise is at 6:46 am and sunset at 8:06 pm. On the last day of September, sunrise is at 7:25 am and sunset at 7:07 pm MDT.
Sunshine
The average sunshine in September in Sun River, Montana, is 9.6h.UV index
In Sun River, Montana, the average daily maximum UV index in September is 4. A UV Index reading of 3 to 5 represents a medium health hazard from unsafe exposure to UV radiation for average individuals.Note: A maximum high daily UV index of 4 during September translates into the following directions:
Heed the precautions - Protecting the skin and eyes from damage is compulsory. The Sun is most powerful around mid-day, so it's a good practice to reduce direct exposure. Opt for tightly woven and loose clothing to enhance protection from the Sun. Bear in mind! The Sun's UV radiation can nearly double in intensity due to the reflective quality of snow.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
What are September temperatures in Sun River?
What is the average humidity in September in Sun River?
How many days does it rain in September in Sun River?
When does it start snowing in Sun River?
What is the average length of the day in September in Sun River?
What time are sunrise and sunset in September in Sun River?
How long on average sun shines in September in Sun River?
What is the UV index reading in September in Sun River?
Average temperature in September
Sun River, MT
- Average high temperature in September: 70.5°F
The warmest month (with the highest average high temperature) is July (82.2°F).
The month with the lowest average high temperature is December (29.5°F).
- Average low temperature in September: 49.5°F
The month with the highest average low temperature is August (56.7°F).
The coldest month (with the lowest average low temperature) is December (17.4°F).
Average pressure in September
Sun River, MT
- Average pressure in September: 29.96"Hg
The months with the highest atmospheric pressure are January and December (30.14"Hg).
The month with the lowest atmospheric pressure is June (29.87"Hg).
Average wind speed in September
Sun River, MT
- Average wind speed in September: 8.2mph
The windiest months (with the highest average wind speed) are January and November (10.7mph).
The calmest month (with the lowest average wind speed) is August (7.3mph).
Average humidity in September
Sun River, MT
- Average humidity in September: 47%
The month with the highest relative humidity is January (78%).
The month with the lowest relative humidity is August (41%).
Average rainfall in September
Sun River, MT
- Average rainfall in September: 1.14"
The wettest month (with the highest rainfall) is June (2.05").
The driest months (with the least rainfall) are January and July (0.63").
Average rainfall days in September
Sun River, MT
- Average rainfall days in September: 8.7 days
The month with the highest number of rainy days is May (15.2 days).
The month with the least rainy days is January (4.8 days).
Average snowfall in September
Sun River, MT
- Average snowfall in September: 2.05"
The month with the highest snowfall is February (6.34").
The months with the least snowfall are June, July and August (0").
Average snowfall days in September
Sun River, MT
- Average snowfall days in September: 0.7 days
The month with the highest number of snowfall days is February (14.4 days).
The months with the least snowfall days are July and August (0 days).
Average daylight in September /
Average sunshine in September
Sun River, MT
- Average daylight in September: 12h and 3min
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 4min
The month with the most sunshine is July (Average sunshine: 11h and 54min).
The months with the least sunshine are January and December (Average sunshine: 5h and 24min).
Average sunshine days in September
Sun River, MT
- Average sunshine days in September: 18.8 days
The month with the most sunshine days is September (18.8 days).
The month with the least sunshine days is April (10.3 days).
Average UV index in September
Sun River, MT
- Average UV index in September: 4
The month with the highest UV index is July (UV index 6).
The months with the lowest UV index are January, February, March, October, November and December (UV index 2).
Average cloud cover in September
Sun River, MT
- Average cloud cover in September: 24
The month with the most cloud cover is February (Cloud cover 47).
The month with the least cloud cover is July (Cloud cover 14).
Average visibility in September
Sun River, 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).
Sun River, Montana, USA
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