December weather forecastWest McLean, VA
December
Weather in December
December, the first month of the winter in West McLean, is also a frosty month, with an average temperature varying between 45.5°F (7.5°C) and 33.1°F (0.6°C).Temperature
With the beginning of December, the average high-temperature shows a small decrease, transitioning from a fresh 54.1°F (12.3°C) in November to a frosty 45.5°F (7.5°C). West McLean experiences an average nighttime temperature of 33.1°F (0.6°C) in the month of December.Humidity
October and December, with an average relative humidity of 76%, are the most humid months.Rainfall
In West McLean, Virginia, in December, during 6.9 rainfall days, 0.67" (17mm) of precipitation is typically accumulated. In West McLean, during the entire year, the rain falls for 109 days and collects up to 9.29" (236mm) of precipitation.Snowfall
January through April, November and December are months with snowfall. In West McLean, in December, during 1.2 snowfall days, 0.28" (7mm) of snow is typically accumulated. In West McLean, during the entire year, snow falls for 10.3 days and aggregates up to 2.28" (58mm) of snow.Daylight
With an average of 9h and 30min of daylight, December has the shortest days of the year.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.UV index
January, 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 exposure to the Sun's UV radiation for average individuals.Note: In December, the average maximum UV index of 2 translates into the following recommendations:
While many people can endure lengthy sun exposure, it remains imperative to safeguard babies, children, and fair-skinned individuals. The solar radiation is most powerful near the mid-day, so the exposure to the direct Sun should be reduced accordingly. Counter UV radiation's ill effects with clothing designed for sun safety and UV-resistant eyewear. Be informed! The Sun's UV radiation can be nearly doubled due to the reflection from snow.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
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 30min
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 6min
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).
