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
Transition into December subtly marks a drop in the average high-temperature, moderately moving from a cool 53.4°F (11.9°C) in November to a frosty 45.3°F (7.4°C). In December, Reston experiences a temperature dip to an average of 32.7°F (0.4°C) at night.Humidity
October and December, with an average relative humidity of 76%, are the most humid months.Rainfall
In Reston, during December, the rain falls for 9.8 days and regularly aggregates up to 2.17" (55mm) of precipitation. Throughout the year, there are 152.8 rainfall days, and 27.64" (702mm) of precipitation is accumulated.Snowfall
Months with snowfall are January through April, November and December. In Reston, in December, snow falls for 2.2 days, with typically accumulated 1.22" (31mm) of snow. Throughout the year, there are 13.9 snowfall days, and 7.2" (183mm) of snow is accumulated.Daylight
December has the shortest days of the year, 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 7:28 am and sunset at 4:57 pm EST.
Sunshine
January, February and December, with an average of 5h of sunshine, are months with the least 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 minimal health hazard from unsafe exposure to UV radiation for the average person.Note: A maximum high daily UV index of 2 during December translates into the following directions:
In contrast to children, who must always be shielded from the sun, most people can tolerate up to an hour of sun exposure without any burns. Solar radiation peaks around mid-day, so it's wise to limit exposure to the Sun at this time. Counter UV radiation's ill effects with clothing designed for sun safety and UV-resistant eyewear. Mind you! Snow reflection can increase the intensity of the Sun's UV radiation nearly twofold.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
What is the usual temperature for Reston in December?
What are the most humid months?
What is the average humidity in December?
How much does it rain in December?
How many days does it snow in December?
What is the month with the shortest days?
What is the average length of the day in December in Reston?
What time are sunrise and sunset in December?
What is the month with the least sunshine?
How many hours of sunshine does Reston have in December?
What are the months with the lowest UV index?
What is the UV index intensity in December?
Average temperature in December
Reston, VA
- Average high temperature in December: 45.3°F
The warmest month (with the highest average high temperature) is July (87.6°F).
The month with the lowest average high temperature is January (39.7°F).
- Average low temperature in December: 32.7°F
The month with the highest average low temperature is July (68.5°F).
The coldest month (with the lowest average low temperature) is January (26.4°F).
Average pressure in December
Reston, 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
Reston, 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
Reston, 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 (69%).
Average rainfall in December
Reston, VA
- Average rainfall in December: 2.17"
The wettest month (with the highest rainfall) is August (3.39").
The driest month (with the least rainfall) is January (1.77").
Average rainfall days in December
Reston, VA
- Average rainfall days in December: 9.8 days
The month with the highest number of rainy days is May (16.3 days).
The month with the least rainy days is November (9.3 days).
Average snowfall in December
Reston, VA
- Average snowfall in December: 1.22"
The month with the highest snowfall is January (2.28").
The months with the least snowfall are May, June, July, August, September and October (0").
Average snowfall days in December
Reston, VA
- Average snowfall days in December: 2.2 days
The month with the highest number of snowfall days is January (4.6 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
Reston, 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 0min
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 0min).
Average sunshine days in December
Reston, VA
- Average sunshine days in December: 17.9 days
The month with the most sunshine days is November (19.3 days).
The month with the least sunshine days is May (12.8 days).
Average UV index in December
Reston, 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
Reston, VA
- Average cloud cover in December: 46
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
Reston, 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).
Reston, Virginia, USA
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