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
Onset of December comes with a temperature decline, the average high falling from a cold 39.6°F (4.2°C) in November to a freezing cold 26.6°F (-3°C). The mean low-temperature during December nights is a still subzero cold 14.9°F (-9.5°C).Humidity
The average relative humidity in December in Harlem is 80%.Rainfall
The months with the least rainfall are February, March and December Rain falls for 7 days and accumulates 0.55" (14mm) of rain.Snowfall
January through May, September through December are months with snowfall. In December, it is snowing for 11.1 days. Throughout December, 3.58" (91mm) of snow is accumulated. Throughout the year, there are 57.6 snowfall days, and 21.69" (551mm) of snow is accumulated.Daylight
With an average of 8h and 24min of daylight, December has the shortest days of the year.On the first day of December, sunrise is at 7:46 am and sunset at 4:22 pm. On the last day of the month, sunrise is at 8:07 am and sunset at 4:29 pm MST.
Sunshine
In December, the average sunshine is 5.6h.UV index
The months with the lowest UV index are January through March, October through December, with an average maximum UV index of 2. A UV Index of 2, and less, symbolizes a minimal health vulnerability from unprotected exposure to Sun's UV rays for the average person.Note: The daily maximum UV index of 2 in December interprets into the following advice:
Most individuals can handle sun exposure for up to an hour without burning, but children must always be shielded from sun exposure. Avoid the Sun's strongest UV rays by seeking shade and limiting exposure during midday. Your best bet for sun defense on the face, eyes, and neck is a hat with a wide brim. Pay attention! The reflection of snow can enhance the Sun's UV radiation almost double.
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 much does it rain in December?
How many days does it snow in December?
What is the month with the shortest days?
How many hours of daylight does Harlem have in December?
When is the sunrise / sunset in December?
How many hours of sunshine does Harlem have in December?
What is the month with the lowest UV index?
How high is the UV index in December in Harlem?
Average temperature in December
Harlem, MT
- Average high temperature in December: 26.6°F
The warmest month (with the highest average high temperature) is July (82°F).
The month with the lowest average high temperature is February (26.2°F).
- Average low temperature in December: 14.9°F
The month with the highest average low temperature is August (60.3°F).
The coldest month (with the lowest average low temperature) is February (12.6°F).
Average pressure in December
Harlem, MT
- Average pressure in December: 30.11"Hg
The month with the highest atmospheric pressure is February (30.13"Hg).
The month with the lowest atmospheric pressure is June (29.83"Hg).
Average wind speed in December
Harlem, MT
- Average wind speed in December: 9.8mph
The windiest month (with the highest average wind speed) is April (10.7mph).
The calmest month (with the lowest average wind speed) is August (8.7mph).
Average humidity in December
Harlem, MT
- Average humidity in December: 80%
The month with the highest relative humidity is January (82%).
The month with the lowest relative humidity is August (42%).
Average rainfall in December
Harlem, MT
- Average rainfall in December: 0.55"
The wettest month (with the highest rainfall) is June (1.85").
The driest months (with the least rainfall) are February, March and December (0.55").
Average rainfall days in December
Harlem, MT
- Average rainfall days in December: 7 days
The month with the highest number of rainy days is May (13.2 days).
The month with the least rainy days is February (4.6 days).
Average snowfall in December
Harlem, MT
- Average snowfall in December: 3.58"
The month with the highest snowfall is January (4.02").
The months with the least snowfall are June, July and August (0").
Average snowfall days in December
Harlem, MT
- Average snowfall days in December: 11.1 days
The month with the highest number of snowfall days is January (12.4 days).
The months with the least snowfall days are June, July and August (0 days).
Average daylight in December /
Average sunshine in December
Harlem, MT
- Average daylight in December: 8h and 2min
The month with the longest days is June (Average daylight: 16h and 6min).
The month with the shortest days is December (Average daylight: 8h and 24min).
- Average sunshine in December: 5h and 4min
The month with the most sunshine is July (Average sunshine: 12h and 0min).
The month with the least sunshine is February (Average sunshine: 5h and 12min).
Average sunshine days in December
Harlem, MT
- Average sunshine days in December: 17 days
The month with the most sunshine days is July (21.6 days).
The month with the least sunshine days is April (12.5 days).
Average UV index in December
Harlem, MT
- Average UV index in December: 2
The months with the highest UV index are June and July (UV index 6).
The months with the lowest UV index are January, February, March, October, November and December (UV index 2).
Average cloud cover in December
Harlem, MT
- Average cloud cover in December: 42
The month with the most cloud cover is February (Cloud cover 45).
The month with the least cloud cover is July (Cloud cover 15).
Average visibility in December
Harlem, 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).
Harlem, Montana, USA
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