December weather forecastMount Vernon, VA
December
Weather in December
The first month of the winter, December, is also a frosty month in Mount Vernon, Virginia, with an average temperature ranging between max 46.2°F (7.9°C) and min 34°F (1.1°C).Temperature
December marks a gentle change in average high-temperature, declining from November's fresh 55°F (12.8°C) to a frosty 46.2°F (7.9°C). Throughout December, Mount Vernon anticipates an average low-temperature of 34°F (1.1°C).Humidity
May, October and December, with an average relative humidity of 76%, are the most humid months.Rainfall
In Mount Vernon, in December, during 10.6 rainfall days, 2.68" (68mm) of precipitation is typically accumulated. In Mount Vernon, Virginia, during the entire year, the rain falls for 158.2 days and collects up to 30.67" (779mm) of precipitation.Snowfall
Months with snowfall are January through April, November and December. In Mount Vernon, during December, snow falls for 2.5 days and regularly aggregates up to 1.02" (26mm) of snow. In Mount Vernon, during the entire year, snow falls for 14.4 days and aggregates up to 7.56" (192mm) of snow.Daylight
December has the shortest days of the year, with an average of 9h and 30min of daylight.On the first day of the month, sunrise is at 7:08 am and sunset at 4:47 pm. On the last day of December, sunrise is at 7:26 am and sunset at 4:57 pm EST.
Sunshine
The average sunshine in December is 5.2h.UV index
The months with the lowest UV index are January and December, with an average maximum UV index of 2. A UV Index estimate of 2, and below, represents a low health risk from exposure to the Sun's UV radiation for the ordinary person.Note: An average UV index of 2 in December transforms into this advice:
The majority are not significantly affected by prolonged sun exposure. Infants, children, and those with fair skin must always have protection. Around midday, solar radiation is most harmful; hence, exposure should be limited. Always opt for UVA and UVB-resistant sunglasses on radiant days. Warning! The reflection from snow can nearly magnify the Sun's UV radiation twofold.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in December
Mount Vernon, VA
- Average high temperature in December: 46.2°F
The warmest month (with the highest average high temperature) is July (87.8°F).
The month with the lowest average high temperature is January (40.6°F).
- Average low temperature in December: 34°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 (27.7°F).
Average pressure in December
Mount Vernon, 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
Mount Vernon, VA
- Average wind speed in December: 6.8mph
The windiest month (with the highest average wind speed) is March (7.8mph).
The calmest month (with the lowest average wind speed) is August (5mph).
Average humidity in December
Mount Vernon, VA
- Average humidity in December: 76%
The months with the highest relative humidity are May, October and December (76%).
The months with the lowest relative humidity are April and July (71%).
Average rainfall in December
Mount Vernon, VA
- Average rainfall in December: 2.68"
The wettest month (with the highest rainfall) is August (3.43").
The driest month (with the least rainfall) is September (1.93").
Average rainfall days in December
Mount Vernon, VA
- Average rainfall days in December: 10.6 days
The month with the highest number of rainy days is May (17.7 days).
The month with the least rainy days is November (8.5 days).
Average snowfall in December
Mount Vernon, VA
- Average snowfall in December: 1.02"
The month with the highest snowfall is January (2.48").
The months with the least snowfall are May, June, July, August, September and October (0").
Average snowfall days in December
Mount Vernon, VA
- Average snowfall days in December: 2.5 days
The month with the highest number of snowfall days is January (4.5 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
Mount Vernon, VA
- Average daylight in December: 9h and 30min
The month with the longest days is June (Average daylight: 14h and 48min).
The month with the shortest days is December (Average daylight: 9h and 30min).
- Average sunshine in December: 5h and 12min
The month with the most sunshine is July (Average sunshine: 10h and 48min).
The month with the least sunshine is February (Average sunshine: 5h and 6min).
Average sunshine days in December
Mount Vernon, VA
- Average sunshine days in December: 17.4 days
The month with the most sunshine days is November (19.8 days).
The month with the least sunshine days is May (11.5 days).
Average UV index in December
Mount Vernon, 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 and December (UV index 2).
Average cloud cover in December
Mount Vernon, 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
Mount Vernon, 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).
