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
Herndon, West Virginia, experiences a moderate temperature shift at the start of December, with average high-temperatures adjusting a bit from a fresh 52°F (11.1°C) in November to a chilly 43.5°F (6.4°C). In Herndon, December nights cool down to an average of 30.7°F (-0.7°C).Humidity
In Herndon, the average relative humidity in December is 81%.Rainfall
In Herndon, in December, during 12.4 rainfall days, 3.15" (80mm) of precipitation is typically accumulated. Throughout the year, there are 180.7 rainfall days, and 32.24" (819mm) of precipitation is accumulated.Snowfall
January through May, October through December are months with snowfall. In Herndon, during December, snow falls for 10.5 days and regularly aggregates up to 5.55" (141mm) of snow. In Herndon, during the entire year, snow falls for 50.3 days and aggregates up to 27.09" (688mm) of snow.Daylight
December has the shortest days of the year, with an average of 9h and 36min of daylight.On the first day of December, sunrise is at 7:21 am and sunset at 5:07 pm. On the last day of the month, sunrise is at 7:39 am and sunset at 5:17 pm EST.
Sunshine
In Herndon, the average sunshine in December is 4.6h.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 of 2, and less, symbolizes a minimal health vulnerability from unprotected exposure to Sun's UV rays for average individuals.Note: During December, 2 as the daily maximum UV index converts into the following advice:
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. The solar radiation around mid-day is intense; avoid the Sun and stay safe. A wide-brimmed hat provides unparalleled sun protection for sensitive areas like the eyes, ears, and neck. Take heed! Reflection from the snow can almost amplify the Sun's UV radiation by double.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Is December cold?
What is the average humidity in December?
How many days does it rain in December?
How many days does it snow in December?
What is the month with the shortest days?
How many hours of daylight does Herndon have in December?
When are sunrise and sunset in December?
How long on average sun shines in December?
What are the months with the lowest UV index?
What is the UV index intensity in December?
Average temperature in December
Herndon, WV
- Average high temperature in December: 43.5°F
The warmest month (with the highest average high temperature) is July (82.8°F).
The month with the lowest average high temperature is January (38.3°F).
- Average low temperature in December: 30.7°F
The month with the highest average low temperature is July (60.1°F).
The coldest month (with the lowest average low temperature) is January (24.8°F).
Average pressure in December
Herndon, WV
- Average pressure in December: 30.14"Hg
The month with the highest atmospheric pressure is November (30.16"Hg).
The month with the lowest atmospheric pressure is June (29.99"Hg).
Average wind speed in December
Herndon, WV
- Average wind speed in December: 6.6mph
The windiest month (with the highest average wind speed) is January (7.4mph).
The calmest month (with the lowest average wind speed) is August (4.2mph).
Average humidity in December
Herndon, WV
- Average humidity in December: 81%
The month with the highest relative humidity is February (83%).
The months with the lowest relative humidity are June, July, August and November (77%).
Average rainfall in December
Herndon, WV
- Average rainfall in December: 3.15"
The wettest months (with the highest rainfall) are February and May (3.43").
The driest month (with the least rainfall) is September (1.57").
Average rainfall days in December
Herndon, WV
- Average rainfall days in December: 12.4 days
The month with the highest number of rainy days is May (20.1 days).
The month with the least rainy days is November (11.3 days).
Average snowfall in December
Herndon, WV
- Average snowfall in December: 5.55"
The month with the highest snowfall is February (6.02").
The months with the least snowfall are June, July, August and September (0").
Average snowfall days in December
Herndon, WV
- Average snowfall days in December: 10.5 days
The month with the highest number of snowfall days is January (13.1 days).
The months with the least snowfall days are June, July, August and September (0 days).
Average daylight in December /
Average sunshine in December
Herndon, WV
- Average daylight in December: 9h and 4min
The month with the longest days is June (Average daylight: 14h and 42min).
The month with the shortest days is December (Average daylight: 9h and 36min).
- Average sunshine in December: 4h and 4min
The month with the most sunshine is August (Average sunshine: 10h and 6min).
The month with the least sunshine is January (Average sunshine: 4h and 12min).
Average sunshine days in December
Herndon, WV
- Average sunshine days in December: 11.7 days
The month with the most sunshine days is November (15.8 days).
The month with the least sunshine days is February (8.3 days).
Average UV index in December
Herndon, WV
- Average UV index in December: 2
The months with the highest UV index are June 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
Herndon, WV
- Average cloud cover in December: 57
The month with the most cloud cover is January (Cloud cover 62).
The month with the least cloud cover is August (Cloud cover 36).
Average visibility in December
Herndon, WV
- Average visibility in December: 5mi
The months with the highest visibility are January, February, March, April, May, June, July, August, September, October, November and December (5mi).
The months with the lowest visibility are January, February, March, April, May, June, July, August, September, October, November and December (5mi).
Herndon, West Virginia, USA
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