December weather forecastManassas, VA
December
Weather in December
December in Manassas brings the full force of winter, with temperatures predominantly dwelling between the monthly high of 45.7°F (7.6°C) and the low of 32.4°F (0.2°C). The month distinguishes itself as the first of the season to record more than an inch of snowfall, indicating a 1.61-inch accumulation. The city succumbs to shorter daylight hours, quickening the arrival of cold winter nights. Rainfall frequency tails off, but the city cannot discount snow events. As the holiday season fills the city with cheer, locals suit up for winter, with stunning snowy landscapes and chill winds painting memorable year-end pictures.Temperature
The transition into December in Manassas subtly indicates a reduction in the average high-temperature, down to a frosty 45.7°F (7.6°C) from November's cool 54.5°F (12.5°C). December nights in Manassas observe an average temperature dip to a cold 32.4°F (0.2°C).Humidity
The most humid month in Manassas is December, with an average relative humidity of 78%.Rainfall
In Manassas, in December, during 10.3 rainfall days, 2.56" (65mm) of precipitation is typically accumulated. In Manassas, during the entire year, the rain falls for 157.5 days and collects up to 30.35" (771mm) of precipitation.Snowfall
Months with snowfall are January through April, November and December. In Manassas, Virginia, in December, snow falls for 2.5 days, with typically accumulated 1.61" (41mm) of snow. In Manassas, during the entire year, snow falls for 15.8 days and aggregates up to 11.5" (292mm) of snow.Daylight
The month with the shortest days is December, with an average of 9h and 30min of daylight.On the first day of the month, sunrise is at 7:09 am and sunset at 4:48 pm. On the last day of December, in Manassas, sunrise is at 7:27 am and sunset at 4:58 pm EST.
Sunshine
The months with the least sunshine are January, February and December, with an average of 5.2h of sunshine.UV index
January, February, 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 low threat to health from exposure to the Sun's UV radiation for the average person.Note: In December, an average UV index of 2 transforms into the following instructions:
Extended sunlight exposure does not pose significant problems for most people, except for children, infants, and people with fair skin who always need shielding. Given the potency of the midday Sun's UV radiation, one should avoid prolonged exposure. For minimizing sun-related eye damage, always choose sunglasses with UVA and UVB coverage. Be aware! The intensity of the Sun's UV radiation can be amplified nearly twice due to snow reflection.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in December
Manassas, VA
- Average high temperature in December: 45.7°F
The warmest month (with the highest average high temperature) is July (88.3°F).
The month with the lowest average high temperature is January (40.6°F).
- Average low temperature in December: 32.4°F
The month with the highest average low temperature is July (67.1°F).
The coldest month (with the lowest average low temperature) is January (26.4°F).
Average pressure in December
Manassas, 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
Manassas, VA
- Average wind speed in December: 6mph
The windiest months (with the highest average wind speed) are March and April (7mph).
The calmest month (with the lowest average wind speed) is August (4.6mph).
Average humidity in December
Manassas, VA
- Average humidity in December: 78%
The month with the highest relative humidity is December (78%).
The month with the lowest relative humidity is July (72%).
Average rainfall in December
Manassas, VA
- Average rainfall in December: 2.56"
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
Manassas, VA
- Average rainfall days in December: 10.3 days
The month with the highest number of rainy days is May (17.4 days).
The month with the least rainy days is November (9.3 days).
Average snowfall in December
Manassas, VA
- Average snowfall in December: 1.61"
The month with the highest snowfall is January (3.7").
The months with the least snowfall are May, June, July, August, September and October (0").
Average snowfall days in December
Manassas, VA
- Average snowfall days in December: 2.5 days
The month with the highest number of snowfall days is February (5.2 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
Manassas, 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 42min).
The months with the least sunshine are January, February and December (Average sunshine: 5h and 12min).
Average sunshine days in December
Manassas, VA
- Average sunshine days in December: 17.3 days
The month with the most sunshine days is November (19.8 days).
The month with the least sunshine days is May (11.7 days).
Average UV index in December
Manassas, 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, February, November and December (UV index 2).
Average cloud cover in December
Manassas, VA
- Average cloud cover in December: 45
The month with the most cloud cover is March (Cloud cover 47).
The month with the least cloud cover is July (Cloud cover 31).
Average visibility in December
Manassas, VA
- Average visibility in December: 5mi
The months with the highest visibility are January, February, March, April, June, July, August and November (6mi).
The months with the lowest visibility are May, September, October and December (5mi).
