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
December, with an average high of 31.1°F (-0.5°C) and a low of 16.7°F (-8.5°C), signifies the coldest month of the year.Humidity
In Decker, Montana, the average relative humidity in December is 75%.Rainfall
The month with the least rainfall is December, when the rain falls for 6.8 days and typically collects 0.67" (17mm) of precipitation.Snowfall
Months with snowfall in Decker are January through May, September through December. In Decker, during December, snow falls for 11.2 days and regularly aggregates up to 3.62" (92mm) of snow. Throughout the year, there are 65.3 snowfall days, and 28.82" (732mm) of snow is accumulated.Daylight
December has the shortest days of the year, with an average of 8h and 48min of daylight.On the first day of December, sunrise is at 7:26 am and sunset at 4:27 pm. On the last day of the month, sunrise is at 7:45 am and sunset at 4:36 pm MST.
Sunshine
The average sunshine in December is 6.1h.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 reading of 2, and below, represents a minimal health vulnerability from unsafe exposure to UV radiation for the average person.Note: In December, the maximum UV index of 2 suggests this advice:
For the majority, extended sun exposure is not of great concern. Infants and people with sensitive skin must always be protected. Considering the Sun's intensity during midday, it's wise to minimize direct exposure. On bright days sunglasses that block both UVA and UVB rays should be worn. A hat with a wide brim is extremely helpful, as it can prevent roughly 50% of UV radiation from reaching the eyes. Be attentive! The reflective property of snow can nearly double the Sun's UV radiation.
Frequently asked questions
What are the coldest months in Decker?
How cold is it in Decker in December?
What is the average humidity in December in Decker?
What is the driest month in Decker?
How much does it rain in Decker in December?
How many days does it snow in December in Decker?
What is the month with the shortest days in Decker?
How many hours of daylight does Decker have in December?
What time are sunrise and sunset in December in Decker?
How long on average sun shines in December in Decker?
What is the month with the lowest UV index in Decker?
What is the UV index intensity in December in Decker?
Average temperature in December
Decker, MT
- Average high temperature in December: 31.1°F
The warmest month (with the highest average high temperature) is July (85.5°F).
The month with the lowest average high temperature is December (31.1°F).
- Average low temperature in December: 16.7°F
The month with the highest average low temperature is July (61.5°F).
The coldest months (with the lowest average low temperature) are January and February (16.2°F).
Average pressure in December
Decker, 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 (29.85"Hg).
Average wind speed in December
Decker, MT
- Average wind speed in December: 6.8mph
The windiest month (with the highest average wind speed) is April (9.1mph).
The calmest months (with the lowest average wind speed) are July and December (6.8mph).
Average humidity in December
Decker, MT
- Average humidity in December: 75%
The months with the highest relative humidity are January and February (79%).
The month with the lowest relative humidity is August (40%).
Average rainfall in December
Decker, MT
- Average rainfall in December: 0.67"
The wettest month (with the highest rainfall) is May (2.64").
The driest month (with the least rainfall) is December (0.67").
Average rainfall days in December
Decker, MT
- Average rainfall days in December: 6.8 days
The month with the highest number of rainy days is May (18 days).
The month with the least rainy days is January (6.3 days).
Average snowfall in December
Decker, MT
- Average snowfall in December: 3.62"
The month with the highest snowfall is February (5.2").
The months with the least snowfall are June, July and August (0").
Average snowfall days in December
Decker, MT
- Average snowfall days in December: 11.2 days
The month with the highest number of snowfall days is February (14.3 days).
The months with the least snowfall days are June, July and August (0 days).
Average daylight in December /
Average sunshine in December
Decker, 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 1min
The months with the most sunshine are July and August (Average sunshine: 11h and 54min).
The month with the least sunshine is February (Average sunshine: 5h and 42min).
Average sunshine days in December
Decker, MT
- Average sunshine days in December: 16.5 days
The month with the most sunshine days is September (18.2 days).
The month with the least sunshine days is May (9.6 days).
Average UV index in December
Decker, 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
Decker, MT
- Average cloud cover in December: 37
The month with the most cloud cover is February (Cloud cover 41).
The months with the least cloud cover are July and August (Cloud cover 14).
Average visibility in December
Decker, 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).
Decker, Montana, USA
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