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 arrival of December corresponds with a minor reduction in the average high-temperature, down from November's cool 54.1°F (12.3°C) to a frosty 45.5°F (7.5°C). Throughout the month of December, West McLean reports a steady low-temperature average of 33.1°F (0.6°C).Humidity
The months with the highest humidity in West McLean are October and December, with an average relative humidity of 76%.Rainfall
In West McLean, Virginia, in December, during 6.9 rainfall days, 0.67" (17mm) of precipitation is typically accumulated. Throughout the year, in West McLean, there are 109 rainfall days, and 9.29" (236mm) of precipitation is accumulated.Snowfall
January through April, November and December are months with snowfall. In West McLean, Virginia, during December, snow falls for 1.2 days and regularly aggregates up to 0.28" (7mm) of snow. Throughout the year, there are 10.3 snowfall days, and 2.28" (58mm) of snow is accumulated.Daylight
December has the shortest days of the year in West McLean, with an average of 9h and 30min of daylight.On the first day of December, sunrise is at 7:09 am and sunset at 4:47 pm. On the last day of the month, sunrise is at 7:27 am and sunset at 4:56 pm EST.
Sunshine
February and December, with an average of 5.1h of sunshine, are months with the least sunshine in West McLean.UV index
The months with the lowest UV index are January, November and December, with an average maximum UV index of 2. A UV Index reading of 2, and below, represents a minimal health vulnerability from unsafe exposure to UV radiation for ordinary individuals.Note: In December, the UV index of 2 transforms into the following advice:
While extended sun exposure does not significantly affect most people, those with sensitive skin, children, and infants should always be protected. Direct exposure to the Sun's intense radiation around midday should be avoided for health reasons. Using UVA and UVB-protective sunglasses and sun-protective clothing is effective against UV radiation. Warning! The reflection from snow can nearly magnify the Sun's UV radiation twofold.
Frequently asked questions
What is the average December temperature in West McLean?
What is the most humid month in West McLean?
What is the average humidity in December in West McLean?
How many days does it rain in December in West McLean?
How many days does it snow in December in West McLean?
What is the month with the shortest days in West McLean?
What is the average length of the day in December in West McLean?
When are sunrise and sunset in December in West McLean?
What are the months with the least sunshine in West McLean?
How long on average sun shines in December in West McLean?
What is the month with the lowest UV index in West McLean?
How high is the UV index in December in West McLean?
Average temperature in December
West McLean, VA
- Average high temperature in December: 45.5°F
The warmest month (with the highest average high temperature) is July (87.4°F).
The month with the lowest average high temperature is January (40.1°F).
- Average low temperature in December: 33.1°F
The month with the highest average low temperature is July (69.1°F).
The coldest month (with the lowest average low temperature) is January (26.8°F).
Average pressure in December
West McLean, VA
- Average pressure in December: 30.11"Hg
The month with the highest atmospheric pressure is November (30.14"Hg).
The month with the lowest atmospheric pressure is June (29.95"Hg).
Average wind speed in December
West McLean, VA
- Average wind speed in December: 6.8mph
The windiest month (with the highest average wind speed) is March (7.7mph).
The calmest month (with the lowest average wind speed) is August (4.9mph).
Average humidity in December
West McLean, VA
- Average humidity in December: 76%
The months with the highest relative humidity are October and December (76%).
The month with the lowest relative humidity is July (70%).
Average rainfall in December
West McLean, VA
- Average rainfall in December: 0.67"
The wettest month (with the highest rainfall) is August (1.5").
The driest months (with the least rainfall) are January and September (0.51").
Average rainfall days in December
West McLean, VA
- Average rainfall days in December: 6.9 days
The month with the highest number of rainy days is July (13.5 days).
The month with the least rainy days is November (5.6 days).
Average snowfall in December
West McLean, VA
- Average snowfall in December: 0.28"
The month with the highest snowfall is January (0.98").
The months with the least snowfall are May, June, July, August, September and October (0").
Average snowfall days in December
West McLean, VA
- Average snowfall days in December: 1.2 days
The month with the highest number of snowfall days is February (3.6 days).
The months with the least snowfall days are May, June, July, August, September and October (0 days).
Average daylight in December /
Average sunshine in December
West McLean, VA
- Average daylight in December: 9h and 3min
The month with the longest days is June (Average daylight: 14h and 54min).
The month with the shortest days is December (Average daylight: 9h and 30min).
- Average sunshine in December: 5h and 1min
The month with the most sunshine is July (Average sunshine: 10h and 54min).
The months with the least sunshine are February and December (Average sunshine: 5h and 6min).
Average sunshine days in December
West McLean, VA
- Average sunshine days in December: 22 days
The month with the most sunshine days is November (23 days).
The month with the least sunshine days is July (14.3 days).
Average UV index in December
West McLean, VA
- Average UV index in December: 2
The months with the highest UV index are May, June, July and August (UV index 6).
The months with the lowest UV index are January, November and December (UV index 2).
Average cloud cover in December
West McLean, VA
- Average cloud cover in December: 45
The month with the most cloud cover is March (Cloud cover 46).
The month with the least cloud cover is July (Cloud cover 30).
Average visibility in December
West McLean, VA
- Average visibility in December: 6mi
The months with the highest visibility are January, February, March, April, June, July, August, September, October, November and December (6mi).
The month with the lowest visibility is May (5mi).
West McLean, Virginia, USA
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