Contents
- Weather in December
- Frequently asked questions
- Average temperature in December
- Average pressure in December
- Average wind speed in December
- Average humidity in December
- Average rainfall in December
- Average rainfall days in December
- Average snowfall in December
- Average snowfall days in December
- Average daylight in December
- Average sunshine in December
- Average sunshine days in December
- Average UV index in December
- Average cloud cover in December
- Average visibility in December
Weather in December
Temperature
The lowest temperatures are recorded in December, with averages reaching a high of 26.4°F (-3.1°C) and a low of 11.3°F (-11.5°C).Humidity
The average relative humidity in December is 84%.Rainfall
In Mammoth, in December, it is raining for 11.9 days, with typically 0.71" (18mm) of accumulated precipitation. Throughout the year, there are 158 rainfall days, and 12.2" (310mm) of precipitation is accumulated.Snowfall
Months with snowfall are January through April, October through December. In Mammoth, in December, during 4.5 snowfall days, 0.87" (22mm) of snow is typically accumulated. In Mammoth, during the entire year, snow falls for 20.8 days and aggregates up to 5.12" (130mm) 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 the month, sunrise is at 7:49 am and sunset at 4:45 pm. On the last day of December, sunrise is at 8:08 am and sunset at 4:54 pm MST.
Sunshine
December has the least sunshine of the year, with an average of 6h of sunshine.UV index
January through April, 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 low health risk from exposure to the Sun's UV radiation for average individuals.Note: The UV index of 2 during December leads to these advisories:
In contrast to children, who must always be shielded from the sun, most people can tolerate up to an hour of sun exposure without any burns. When the Sun's UV radiation is most intense during midday, it's best to find shade and limit exposure. Clothes that are both tight-knit and comfortably loose are prime choices for sun protection. Notice! The UV radiation of the Sun can be intensified nearly twofold due to the reflective quality of snow.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
What part of the year is the coldest?
How cold is December?
What is the average humidity in December?
How many days does it rain in December?
How many days does it snow in December?
What is the month with the shortest days in Mammoth?
What is the average length of the day in December?
When are sunrise and sunset in December?
What is the month with the least sunshine?
How long on average sun shines in December in Mammoth?
What are the months with the lowest UV index?
What is the UV index reading in December in Mammoth?
Average temperature in December
Mammoth, MT
- Average high temperature in December: 26.4°F
The warmest month (with the highest average high temperature) is July (79.5°F).
The month with the lowest average high temperature is December (26.4°F).
- Average low temperature in December: 11.3°F
The month with the highest average low temperature is July (47.7°F).
The coldest month (with the lowest average low temperature) is December (11.3°F).
Average pressure in December
Mammoth, MT
- Average pressure in December: 30.22"Hg
The month with the highest atmospheric pressure is January (30.23"Hg).
The month with the lowest atmospheric pressure is June (29.92"Hg).
Average wind speed in December
Mammoth, MT
- Average wind speed in December: 6.1mph
The windiest month (with the highest average wind speed) is November (6.3mph).
The calmest month (with the lowest average wind speed) is August (4.6mph).
Average humidity in December
Mammoth, MT
- Average humidity in December: 84%
The month with the highest relative humidity is January (85%).
The months with the lowest relative humidity are July and August (46%).
Average rainfall in December
Mammoth, MT
- Average rainfall in December: 0.71"
The wettest month (with the highest rainfall) is May (1.85").
The driest month (with the least rainfall) is January (0.59").
Average rainfall days in December
Mammoth, MT
- Average rainfall days in December: 11.9 days
The month with the highest number of rainy days is April (18.6 days).
The month with the least rainy days is August (8.6 days).
Average snowfall in December
Mammoth, MT
- Average snowfall in December: 0.87"
The month with the highest snowfall is February (1.81").
The months with the least snowfall are May, June, July, August and September (0").
Average snowfall days in December
Mammoth, MT
- Average snowfall days in December: 4.5 days
The month with the highest number of snowfall days is February (6.2 days).
The months with the least snowfall days are May, June, July, August and September (0 days).
Average daylight in December /
Average sunshine in December
Mammoth, MT
- Average daylight in December: 8h and 5min
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: 6h and 0min
The month with the most sunshine is July (Average sunshine: 11h and 54min).
The month with the least sunshine is December (Average sunshine: 6h and 0min).
Average sunshine days in December
Mammoth, MT
- Average sunshine days in December: 14.8 days
The month with the most sunshine days is July (17.8 days).
The month with the least sunshine days is April (7.8 days).
Average UV index in December
Mammoth, 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, February, March, April, October, November and December (UV index 2).
Average cloud cover in December
Mammoth, MT
- Average cloud cover in December: 40
The month with the most cloud cover is February (Cloud cover 42).
The months with the least cloud cover are July and August (Cloud cover 14).
Average visibility in December
Mammoth, MT
- Average visibility in December: 5mi
The months with the highest visibility are March, April, May, June, July, August, September, October and November (6mi).
The months with the lowest visibility are January, February and December (5mi).
Mammoth, Montana, USA
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