December weather forecastGrantsdale, MT
December
Weather in December
December, the first month of the winter in Grantsdale, is also a subzero cold month, with an average temperature ranging between min 14°F (-10°C) and max 26.8°F (-2.9°C).Temperature
In Grantsdale, December is the month with the lowest recorded average temperatures, measuring a high of 26.8°F (-2.9°C) and a low of 14°F (-10°C).Humidity
In Grantsdale, the average relative humidity in December is 87%.Rainfall
In Grantsdale, in December, it is raining for 12.9 days, with typically 1.97" (50mm) of accumulated precipitation. In Grantsdale, during the entire year, the rain falls for 163.6 days and collects up to 20.83" (529mm) of precipitation.Snowfall
January through May, September through December are months with snowfall. In Grantsdale, in December, snow falls for 18.6 days, with typically accumulated 10.55" (268mm) of snow. In Grantsdale, during the entire year, snow falls for 101.1 days and aggregates up to 59.17" (1503mm) of snow.Daylight
The month with the shortest days is December, with an average of 8h and 42min of daylight.On the first day of December, sunrise is at 7:59 am and sunset at 4:52 pm. On the last day of the month, sunrise is at 8:19 am and sunset at 5:00 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 February and December, with an average maximum UV index of 1. A UV Index value of 2, and less, symbolizes a minimal health hazard from exposure to the Sun's UV radiation for ordinary individuals.Note: In December, the average maximum UV index of 1 translates into the following recommendations:
Those with sensitive skin, infants, and children require constant safeguarding from prolonged sun exposure. Given the potency of the midday Sun's UV radiation, one should avoid prolonged exposure. Loose clothes with a tight weave are optimal for safeguarding yourself against the Sun's rays. Mind you! Snow reflection can increase the intensity of the Sun's UV radiation nearly twofold.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in December
Grantsdale, MT
- Average high temperature in December: 26.8°F
The warmest month (with the highest average high temperature) is July (77°F).
The month with the lowest average high temperature is December (26.8°F).
- Average low temperature in December: 14°F
The month with the highest average low temperature is August (46.9°F).
The coldest month (with the lowest average low temperature) is December (14°F).
Average pressure in December
Grantsdale, MT
- Average pressure in December: 30.19"Hg
The month with the highest atmospheric pressure is January (30.21"Hg).
The month with the lowest atmospheric pressure is June (29.93"Hg).
Average wind speed in December
Grantsdale, MT
- Average wind speed in December: 5.2mph
The windiest month (with the highest average wind speed) is January (5.3mph).
The calmest month (with the lowest average wind speed) is August (4.1mph).
Average humidity in December
Grantsdale, MT
- Average humidity in December: 87%
The month with the highest relative humidity is January (89%).
The month with the lowest relative humidity is August (50%).
Average rainfall in December
Grantsdale, MT
- Average rainfall in December: 1.97"
The wettest months (with the highest rainfall) are February and April (2.36").
The driest month (with the least rainfall) is August (0.75").
Average rainfall days in December
Grantsdale, MT
- Average rainfall days in December: 12.9 days
The month with the highest number of rainy days is May (19.5 days).
The month with the least rainy days is July (8 days).
Average snowfall in December
Grantsdale, MT
- Average snowfall in December: 10.55"
The month with the highest snowfall is February (13.03").
The months with the least snowfall are June, July and August (0").
Average snowfall days in December
Grantsdale, MT
- Average snowfall days in December: 18.6 days
The month with the highest number of snowfall days is February (19.3 days).
The months with the least snowfall days are June, July and August (0 days).
Average daylight in December /
Average sunshine in December
Grantsdale, MT
- Average daylight in December: 8h and 42min
The month with the longest days is June (Average daylight: 15h and 42min).
The month with the shortest days is December (Average daylight: 8h and 42min).
- Average sunshine in December: 5h and 24min
The months with the most sunshine are July and August (Average sunshine: 11h and 42min).
The months with the least sunshine are January and December (Average sunshine: 5h and 24min).
Average sunshine days in December
Grantsdale, MT
- Average sunshine days in December: 10 days
The month with the most sunshine days is July (18.9 days).
The month with the least sunshine days is February (5.6 days).
Average UV index in December
Grantsdale, MT
- Average UV index in December: 1
The month with the highest UV index is July (UV index 5).
The months with the lowest UV index are February and December (UV index 1).
Average cloud cover in December
Grantsdale, MT
- Average cloud cover in December: 48
The month with the most cloud cover is February (Cloud cover 51).
The month with the least cloud cover is August (Cloud cover 13).
Average visibility in December
Grantsdale, MT
- Average visibility in December: 4mi
The months with the highest visibility are May, June, July, August, September and October (6mi).
The months with the lowest visibility are January, February, March and December (4mi).
