December weather forecastShelby, MT
December
Weather in December
As the year comes to a close, December signifies the onset of winter in Shelby, Montana. Low temperatures average around 15.4°F (-9.2°C), bringing harsh cold and regular snowfall. The shorter daylight hours and frequent snowfall of 2.28" (58mm) set the stage for a white Christmas. The city dresses up in festive lights, despite the cloud coverage and snow adding a quintessential charm. Outdoor activities transition to winter sports, with residents heading to the slopes for skiing and snowboarding.Temperature
December brings the lowest temperatures, with an average high of 27.7°F (-2.4°C) and an average low of 15.4°F (-9.2°C).Humidity
In December, the average relative humidity is 77%.Rainfall
January and December are months with the least rain when the rain falls for 3.3 days and typically aggregates up to 0.39" (10mm) of rain.Snowfall
Months with snowfall in Shelby are January through May, September through December. In Shelby, during December, snow falls for 9.5 days and regularly aggregates up to 2.28" (58mm) of snow. Throughout the year, there are 53.7 snowfall days, and 20.47" (520mm) of snow is accumulated.Daylight
With an average of 8h and 24min of daylight, December has the shortest days of the year.On the first day of December, sunrise is at 7:59 am and sunset at 4:34 pm. On the last day of the month, sunrise is at 8:19 am and sunset at 4:42 pm MST.
Sunshine
The average sunshine in December in Shelby is 5.5h.UV index
January through March, October through December, with an average maximum UV index of 2, are months with the lowest UV index. A UV Index estimate of 2, and below, represents a minimal health vulnerability from exposure to the Sun's UV radiation for ordinary individuals.Note: A daily high UV index of 2 in December leads to these guidelines:
While many people can endure lengthy sun exposure, it remains imperative to safeguard babies, children, and fair-skinned individuals. The solar radiation is most powerful near the mid-day, so the exposure to the direct Sun should be reduced accordingly. Loose clothes with a tight weave are optimal for safeguarding yourself against the Sun's rays. Be advised! The UV radiation from the Sun can be almost doubled due to the reflective properties of snow.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in December
Shelby, MT
- Average high temperature in December: 27.7°F
The warmest month (with the highest average high temperature) is July (80.8°F).
The month with the lowest average high temperature is December (27.7°F).
- Average low temperature in December: 15.4°F
The month with the highest average low temperature is August (58.3°F).
The coldest month (with the lowest average low temperature) is December (15.4°F).
Average pressure in December
Shelby, MT
- Average pressure in December: 30.11"Hg
The month with the highest atmospheric pressure is January (30.13"Hg).
The month with the lowest atmospheric pressure is June (29.86"Hg).
Average wind speed in December
Shelby, MT
- Average wind speed in December: 10mph
The windiest month (with the highest average wind speed) is April (11mph).
The calmest month (with the lowest average wind speed) is August (8.7mph).
Average humidity in December
Shelby, MT
- Average humidity in December: 77%
The month with the highest relative humidity is January (80%).
The month with the lowest relative humidity is August (40%).
Average rainfall in December
Shelby, MT
- Average rainfall in December: 0.39"
The wettest month (with the highest rainfall) is June (2.01").
The driest months (with the least rainfall) are January and December (0.39").
Average rainfall days in December
Shelby, MT
- Average rainfall days in December: 3.3 days
The month with the highest number of rainy days is May (13.9 days).
The month with the least rainy days is February (3.1 days).
Average snowfall in December
Shelby, MT
- Average snowfall in December: 2.28"
The month with the highest snowfall is February (4.17").
The months with the least snowfall are June, July and August (0").
Average snowfall days in December
Shelby, MT
- Average snowfall days in December: 9.5 days
The month with the highest number of snowfall days is February (10.3 days).
The months with the least snowfall days are July and August (0 days).
Average daylight in December /
Average sunshine in December
Shelby, MT
- Average daylight in December: 8h and 24min
The month with the longest days is June (Average daylight: 16h and 6min).
The month with the shortest days is December (Average daylight: 8h and 24min).
- Average sunshine in December: 5h and 30min
The month with the most sunshine is July (Average sunshine: 11h and 54min).
The month with the least sunshine is January (Average sunshine: 5h and 24min).
Average sunshine days in December
Shelby, MT
- Average sunshine days in December: 20.8 days
The month with the most sunshine days is September (22.2 days).
The month with the least sunshine days is April (14.7 days).
Average UV index in December
Shelby, 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
Shelby, MT
- Average cloud cover in December: 42
The month with the most cloud cover is February (Cloud cover 46).
The month with the least cloud cover is July (Cloud cover 15).
Average visibility in December
Shelby, 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).
