December weather forecastSun River, MT
December
Weather in December
December, the first month of the winter in Sun River, is also a subzero cold month, with an average temperature varying between 29.5°F (-1.4°C) and 17.4°F (-8.1°C).Temperature
Sun River records the coldest temperatures in December, averaging a high of 29.5°F (-1.4°C) and a low of 17.4°F (-8.1°C).Humidity
In Sun River, the average relative humidity in December is 77%.Rainfall
In Sun River, in December, during 4.9 rainfall days, 0.67" (17mm) of precipitation is typically accumulated. Throughout the year, in Sun River, there are 112.8 rainfall days, and 12.95" (329mm) of precipitation is accumulated.Snowfall
January through May, September through December are months with snowfall in Sun River, Montana. In December, it is snowing for 12.4 days. Throughout December, 4.37" (111mm) of snow is accumulated. In Sun River, during the entire year, snow falls for 69.4 days and aggregates up to 35.35" (898mm) of snow.Daylight
The month with the shortest days is December, with an average of 8h and 30min of daylight.On the first day of December, sunrise is at 7:54 am and sunset at 4:37 pm. On the last day of the month, sunrise is at 8:14 am and sunset at 4:45 pm MST.
Sunshine
January and December, with an average of 5.4h of sunshine, are months with the least sunshine.UV index
The months with the lowest UV index are January through March, October through December, with an average maximum UV index of 2. A UV Index of 2, and less, symbolizes a minimal health hazard from unprotected exposure to Sun's UV rays for average individuals.Note: The UV index of 2 in December translates into these instructions:
Most individuals can handle sun exposure for up to an hour without burning, but children must always be shielded from sun exposure. To prevent harmful UV exposure, minimize direct contact with the Sun around midday. Equip yourself with UVA and UVB-filtering sunglasses on clear, sunny days. Heads up! The UV radiation from the Sun can almost be doubled by snow reflection.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in December
Sun River, MT
- Average high temperature in December: 29.5°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 December: 17.4°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 December
Sun River, MT
- Average pressure in December: 30.14"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 December
Sun River, MT
- Average wind speed in December: 10.4mph
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 December
Sun River, MT
- Average humidity in December: 77%
The month with the highest relative humidity is January (78%).
The month with the lowest relative humidity is August (41%).
Average rainfall in December
Sun River, MT
- Average rainfall in December: 0.67"
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 December
Sun River, MT
- Average rainfall days in December: 4.9 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 December
Sun River, MT
- Average snowfall in December: 4.37"
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 December
Sun River, MT
- Average snowfall days in December: 12.4 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 December /
Average sunshine in December
Sun River, MT
- Average daylight in December: 8h and 30min
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 December: 5h and 24min
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 December
Sun River, MT
- Average sunshine days in December: 17.7 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 December
Sun River, MT
- Average UV index in December: 2
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 December
Sun River, MT
- Average cloud cover in December: 43
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 December
Sun River, MT
- Average visibility in December: 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).
