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
December's onset introduces a mild reduction in the average high-temperature, from a cool 52.5°F (11.4°C) in November to a frosty 44.1°F (6.7°C). An average low-temperature of 30°F (-1.1°C) is observed during December nights.Humidity
The average relative humidity in December is 77%.Rainfall
In Grottoes, in December, during 9.6 rainfall days, 2.64" (67mm) of precipitation is typically accumulated. Throughout the year, there are 164.3 rainfall days, and 30.08" (764mm) of precipitation is accumulated.Snowfall
January through May, October through December are months with snowfall. In Grottoes, during December, snow falls for 3.3 days and regularly aggregates up to 2.44" (62mm) of snow. In Grottoes, during the entire year, snow falls for 21.7 days and aggregates up to 16.69" (424mm) of snow.Daylight
The month with the shortest days is December, with an average of 9h and 36min of daylight.On the first day of December, sunrise is at 7:13 am and sunset at 4:55 pm. On the last day of the month, sunrise is at 7:31 am and sunset at 5:05 pm EST.
Sunshine
December has the least sunshine of the year, with an average of 5.3h of sunshine.UV index
The months with the lowest UV index are January, February, November and December, with an average maximum UV index of 2. A UV Index reading of 2, and below, represents a low threat to health from exposure to the Sun's UV radiation for average individuals.Note: The maximum daily UV index of 2 in December converts into the following recommendations:
While extended sun exposure does not significantly affect most people, those with sensitive skin, children, and infants should always be protected. For skin protection, it's recommended to minimize Sun exposure during its peak hours around midday. Tightly woven clothing, when worn loosely, shields effectively against the Sun. Heed this! Snow reflection can almost augment the UV radiation of the sun 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 Grottoes have in December?
What time are sunrise and sunset in December?
What is the month with the least sunshine?
How many hours of sunshine does Grottoes have in December?
What are the months with the lowest UV index?
What is the UV index reading in December?
Average temperature in December
Grottoes, VA
- Average high temperature in December: 44.1°F
The warmest month (with the highest average high temperature) is July (84.6°F).
The month with the lowest average high temperature is January (39°F).
- Average low temperature in December: 30°F
The month with the highest average low temperature is July (62.2°F).
The coldest month (with the lowest average low temperature) is January (24.3°F).
Average pressure in December
Grottoes, VA
- Average pressure in December: 30.12"Hg
The month with the highest atmospheric pressure is November (30.15"Hg).
The month with the lowest atmospheric pressure is June (29.96"Hg).
Average wind speed in December
Grottoes, VA
- Average wind speed in December: 5.5mph
The windiest months (with the highest average wind speed) are February and April (6.6mph).
The calmest month (with the lowest average wind speed) is August (4.2mph).
Average humidity in December
Grottoes, VA
- Average humidity in December: 77%
The months with the highest relative humidity are May, September and October (78%).
The months with the lowest relative humidity are January, June and July (74%).
Average rainfall in December
Grottoes, VA
- Average rainfall in December: 2.64"
The wettest month (with the highest rainfall) is May (3.27").
The driest month (with the least rainfall) is January (1.89").
Average rainfall days in December
Grottoes, VA
- Average rainfall days in December: 9.6 days
The month with the highest number of rainy days is May (18.8 days).
The month with the least rainy days is November (8.6 days).
Average snowfall in December
Grottoes, VA
- Average snowfall in December: 2.44"
The month with the highest snowfall is March (4.53").
The months with the least snowfall are June, July, August and September (0").
Average snowfall days in December
Grottoes, VA
- Average snowfall days in December: 3.3 days
The month with the highest number of snowfall days is February (6.3 days).
The months with the least snowfall days are June, July, August and September (0 days).
Average daylight in December /
Average sunshine in December
Grottoes, VA
- Average daylight in December: 9h and 4min
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 36min).
- Average sunshine in December: 5h and 2min
The month with the most sunshine is July (Average sunshine: 10h and 36min).
The month with the least sunshine is December (Average sunshine: 5h and 18min).
Average sunshine days in December
Grottoes, VA
- Average sunshine days in December: 18.4 days
The month with the most sunshine days is November (19.1 days).
The month with the least sunshine days is May (10.8 days).
Average UV index in December
Grottoes, VA
- Average UV index in December: 2
The months with the highest UV index are May, June and July (UV index 6).
The months with the lowest UV index are January, February, November and December (UV index 2).
Average cloud cover in December
Grottoes, VA
- Average cloud cover in December: 43
The month with the most cloud cover is March (Cloud cover 46).
The months with the least cloud cover are June and July (Cloud cover 31).
Average visibility in December
Grottoes, VA
- Average visibility in December: 5mi
The months with the highest visibility are April, June, July, August and November (6mi).
The months with the lowest visibility are January, February, March, May, September, October and December (5mi).
Grottoes, Virginia, USA
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