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's arrival correlates with a reduction in the average high-temperature, down from a wintry 39.6°F (4.2°C) in November to a subzero cold 25.9°F (-3.4°C). In Zortman, an average temperature of 13.8°F (-10.1°C) is noted during December nights.Humidity
In Zortman, the average relative humidity in December is 82%.Rainfall
The months with the least rainfall are February and December Rain falls for 4 days and accumulates 0.55" (14mm) of rain.Snowfall
Months with snowfall are January through May, September through December. December is the month with the most snowfall. Snow falls for 12.7 days and accumulates 3.9" (99mm) of snow.Daylight
The month with the shortest days is December, with an average of 8h and 30min of daylight.On the first day of the month, sunrise is at 7:43 am and sunset at 4:23 pm. On the last day of December, sunrise is at 8:03 am and sunset at 4:31 pm MST.
Sunshine
In December, the average sunshine is 5h.UV index
December is the month with the lowest UV index, with an average maximum UV index of 1. A UV Index value of 2, and less, symbolizes a low threat to health from unsafe exposure to UV radiation for the ordinary person.Note: A maximum high UV index of 1 in December translates into the following recommendations:
People with sensitive skin, children, and babies should always be protected from prolonged sun exposure. Exposing oneself to the midday Sun can be harmful due to the strong UV radiation; limit your time outside. In bright sunlight, prioritize sunglasses that grant protection from UVA and UVB radiation. Take careful note! The UV radiation of the Sun can be nearly doubled by snow reflection.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
How cold is it in December?
What is the average humidity in December?
What is the driest month?
How many days does it rain in December?
When does it snow the most in Zortman?
How many days does it snow in December?
What is the month with the shortest days?
What is the average length of the day in December?
What time are sunrise and sunset in December?
How long on average sun shines in December?
When is the lowest UV index?
What is the UV index intensity in December?
Average temperature in December
Zortman, MT
- Average high temperature in December: 25.9°F
The warmest month (with the highest average high temperature) is July (83.5°F).
The months with the lowest average high temperature are January and February (25.7°F).
- Average low temperature in December: 13.8°F
The month with the highest average low temperature is July (62.4°F).
The coldest month (with the lowest average low temperature) is January (11.8°F).
Average pressure in December
Zortman, MT
- Average pressure in December: 30.12"Hg
The month with the highest atmospheric pressure is February (30.14"Hg).
The month with the lowest atmospheric pressure is June (29.83"Hg).
Average wind speed in December
Zortman, MT
- Average wind speed in December: 9.1mph
The windiest month (with the highest average wind speed) is April (11.2mph).
The calmest month (with the lowest average wind speed) is February (8.8mph).
Average humidity in December
Zortman, MT
- Average humidity in December: 82%
The month with the highest relative humidity is January (84%).
The month with the lowest relative humidity is August (41%).
Average rainfall in December
Zortman, MT
- Average rainfall in December: 0.55"
The wettest months (with the highest rainfall) are May and June (1.89").
The driest months (with the least rainfall) are February and December (0.55").
Average rainfall days in December
Zortman, MT
- Average rainfall days in December: 4 days
The month with the highest number of rainy days is May (14.1 days).
The month with the least rainy days is December (4 days).
Average snowfall in December
Zortman, MT
- Average snowfall in December: 3.9"
The month with the highest snowfall is December (3.9").
The months with the least snowfall are June, July and August (0").
Average snowfall days in December
Zortman, MT
- Average snowfall days in December: 12.7 days
The month with the highest number of snowfall days is December (12.7 days).
The months with the least snowfall days are June, July and August (0 days).
Average daylight in December /
Average sunshine in December
Zortman, MT
- Average daylight in December: 8h and 3min
The month with the longest days is June (Average daylight: 16h and 0min).
The month with the shortest days is December (Average daylight: 8h and 30min).
- Average sunshine in December: 5h and 0min
The month with the most sunshine is July (Average sunshine: 11h and 48min).
The month with the least sunshine is February (Average sunshine: 4h and 48min).
Average sunshine days in December
Zortman, MT
- Average sunshine days in December: 16.7 days
The month with the most sunshine days is September (19.6 days).
The month with the least sunshine days is April (13.4 days).
Average UV index in December
Zortman, MT
- Average UV index in December: 1
The month with the highest UV index is July (UV index 7).
The month with the lowest UV index is December (UV index 1).
Average cloud cover in December
Zortman, MT
- Average cloud cover in December: 47
The month with the most cloud cover is February (Cloud cover 49).
The months with the least cloud cover are July and August (Cloud cover 17).
Average visibility in December
Zortman, MT
- Average visibility in December: 6mi
The months with the highest visibility are February, March, April, May, June, July, August, September, October, November and December (6mi).
The month with the lowest visibility is January (5mi).
Zortman, Montana, USA
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