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
In Custer, the coldest months are January and December, registering an average high-temperature of 31.1°F (-0.5°C).Humidity
In December, the average relative humidity in Custer is 75%.Rainfall
December is the month with the least rainfall. Rain falls for 4.5 days and accumulates 0.55" (14mm) of precipitation.Snowfall
January through May, September through December are months with snowfall. In Custer, in December, during 8.9 snowfall days, 2.76" (70mm) of snow is typically accumulated. In Custer, during the entire year, snow falls for 48.3 days and aggregates up to 17.68" (449mm) 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 the month, sunrise is at 7:32 am and sunset at 4:26 pm. On the last day of December, sunrise is at 7:52 am and sunset at 4:34 pm MST.
Sunshine
In December, the average sunshine is 5.4h.UV index
January through March, November and 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 threat to health from exposure to the Sun's UV radiation for average individuals.Note: The average daily UV index of 2 in December transforms into the following instructions:
It is important to always shield children, babies, and individuals with sensitive skin from prolonged exposure to the sun. The Sun is most powerful around mid-day, so it's a good practice to reduce direct exposure. To mitigate harm from sun exposure, pick sunglasses offering UVA and UVB defense. 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
What part of the year is the coldest?
How cold is it in December?
What is the average humidity in December?
What is the driest month?
How much does it rain in December?
How much does it snow in December?
What is the month with the shortest days?
What is the average length of the day in December?
When is the sunrise / sunset in December?
How many hours of sunshine does Custer have in December?
When is the lowest UV index?
What is the UV index intensity in December?
Average temperature in December
Custer, MT
- Average high temperature in December: 31.1°F
The warmest month (with the highest average high temperature) is July (86.5°F).
The months with the lowest average high temperature are January and December (31.1°F).
- Average low temperature in December: 18.5°F
The month with the highest average low temperature is July (64.2°F).
The coldest month (with the lowest average low temperature) is January (17.6°F).
Average pressure in December
Custer, MT
- Average pressure in December: 30.12"Hg
The month with the highest atmospheric pressure is January (30.13"Hg).
The month with the lowest atmospheric pressure is June (29.84"Hg).
Average wind speed in December
Custer, MT
- Average wind speed in December: 9.4mph
The windiest month (with the highest average wind speed) is April (10.2mph).
The calmest months (with the lowest average wind speed) are July and August (8.2mph).
Average humidity in December
Custer, MT
- Average humidity in December: 75%
The month with the highest relative humidity is January (79%).
The month with the lowest relative humidity is August (38%).
Average rainfall in December
Custer, MT
- Average rainfall in December: 0.55"
The wettest month (with the highest rainfall) is May (1.85").
The driest month (with the least rainfall) is December (0.55").
Average rainfall days in December
Custer, MT
- Average rainfall days in December: 4.5 days
The month with the highest number of rainy days is May (14.3 days).
The month with the least rainy days is December (4.5 days).
Average snowfall in December
Custer, MT
- Average snowfall in December: 2.76"
The month with the highest snowfall is February (4.29").
The months with the least snowfall are June, July and August (0").
Average snowfall days in December
Custer, MT
- Average snowfall days in December: 8.9 days
The month with the highest number of snowfall days is February (10.6 days).
The months with the least snowfall days are June, July and August (0 days).
Average daylight in December /
Average sunshine in December
Custer, MT
- Average daylight in December: 8h and 4min
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 2min
The month with the most sunshine is July (Average sunshine: 11h and 48min).
The month with the least sunshine is February (Average sunshine: 5h and 12min).
Average sunshine days in December
Custer, MT
- Average sunshine days in December: 18.1 days
The month with the most sunshine days is November (19.2 days).
The month with the least sunshine days is April (13.5 days).
Average UV index in December
Custer, MT
- Average UV index in December: 2
The month with the highest UV index is July (UV index 7).
The months with the lowest UV index are January, February, March, November and December (UV index 2).
Average cloud cover in December
Custer, MT
- Average cloud cover in December: 44
The month with the most cloud cover is February (Cloud cover 46).
The months with the least cloud cover are July and August (Cloud cover 15).
Average visibility in December
Custer, 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).
Custer, Montana, USA
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