December weather forecastBig Sky, MT
December
Weather in December
December brings Big Sky full circle as it plunges back into the height of winter. The thermometer continues to drop, averaging highs of only 22.5°F (-5.3°C). Thunderous snowfall covers the town, preparing for an array of winter activities once again. Despite being the darkest month of the year, it can very much be the brightest, with Christmas lights sporadically punctuating the winter nights. December's weather wraps up the year on a chilly note, promising the return of the Big Sky winter wonderland.Temperature
With average temperatures fluctuating between a high of 22.5°F (-5.3°C) and a low of 7.9°F (-13.4°C), December stands out as the coldest month.Humidity
In Big Sky, the average relative humidity in December is 89%.Rainfall
In Big Sky, during December, the rain falls for 6.3 days and regularly aggregates up to 1.34" (34mm) of precipitation. In Big Sky, Montana, during the entire year, the rain falls for 116.1 days and collects up to 23.5" (597mm) of precipitation.Snowfall
Months with snowfall are January through December. In Big Sky, in December, snow falls for 19.1 days, with typically accumulated 11.1" (282mm) of snow. In Big Sky, during the entire year, snow falls for 151.6 days and aggregates up to 124.06" (3151mm) of snow.Daylight
The month with the shortest days is December, with an average of 8h and 48min of daylight.On the first day of December, sunrise is at 7:44 am and sunset at 4:44 pm. On the last day of the month, sunrise is at 8:04 am and sunset at 4:52 pm MST.
Sunshine
In December, the average sunshine is 4.8h.UV index
The average daily maximum UV index in December in Big Sky, Montana, is 2. A UV Index reading of 2, and below, represents a low threat to health from exposure to the Sun's UV rays for ordinary individuals.Note: The maximum daily UV index of 2 in December converts into the following recommendations:
Children, infants, and individuals with sensitive skin should be constantly protected from extended sun exposure. During midday, the Sun's radiation is strongest, and it's advisable to reduce direct exposure. Sunglasses that guard against UVA and UVB rays are pivotal in minimizing sun-induced ocular damage. 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
Big Sky, MT
- Average high temperature in December: 22.5°F
The warmest month (with the highest average high temperature) is July (74.8°F).
The month with the lowest average high temperature is December (22.5°F).
- Average low temperature in December: 7.9°F
The month with the highest average low temperature is August (45.1°F).
The coldest month (with the lowest average low temperature) is December (7.9°F).
Average pressure in December
Big Sky, MT
- Average pressure in December: 30.21"Hg
The month with the highest atmospheric pressure is January (30.22"Hg).
The month with the lowest atmospheric pressure is June (29.91"Hg).
Average wind speed in December
Big Sky, MT
- Average wind speed in December: 6.8mph
The windiest month (with the highest average wind speed) is January (7.1mph).
The calmest month (with the lowest average wind speed) is August (4.8mph).
Average humidity in December
Big Sky, MT
- Average humidity in December: 89%
The months with the highest relative humidity are January and February (90%).
The month with the lowest relative humidity is August (51%).
Average rainfall in December
Big Sky, MT
- Average rainfall in December: 1.34"
The wettest months (with the highest rainfall) are April and May (2.91").
The driest month (with the least rainfall) is July (1.18").
Average rainfall days in December
Big Sky, MT
- Average rainfall days in December: 6.3 days
The month with the highest number of rainy days is June (16.6 days).
The month with the least rainy days is February (4.3 days).
Average snowfall in December
Big Sky, MT
- Average snowfall in December: 11.1"
The month with the highest snowfall is April (19.88").
The month with the least snowfall is August (0.08").
Average snowfall days in December
Big Sky, MT
- Average snowfall days in December: 19.1 days
The month with the highest number of snowfall days is March (21 days).
The month with the least snowfall days is August (0.3 days).
Average daylight in December /
Average sunshine in December
Big Sky, MT
- Average daylight in December: 8h and 48min
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 December: 4h and 48min
The month with the most sunshine is July (Average sunshine: 11h and 42min).
The month with the least sunshine is January (Average sunshine: 4h and 42min).
Average sunshine days in December
Big Sky, MT
- Average sunshine days in December: 12.2 days
The month with the most sunshine days is September (14.5 days).
The month with the least sunshine days is May (5.7 days).
Average UV index in December
Big Sky, MT
- Average UV index in December: 2
The month with the highest UV index is July (UV index 5).
The months with the lowest UV index are January and February (UV index 1).
Average cloud cover in December
Big Sky, MT
- Average cloud cover in December: 56
The month with the most cloud cover is February (Cloud cover 60).
The month with the least cloud cover is July (Cloud cover 17).
Average visibility in December
Big Sky, MT
- Average visibility in December: 4mi
The months with the highest visibility are June, July, August, September and October (6mi).
The months with the lowest visibility are January, February, March, April and December (4mi).
