December weather forecast and climate
Keystone, West VA

Weather in December

December, the first month of the winter, in Keystone, is also a frosty month, with average temperature fluctuating between 44.4°F (6.9°C) and 31.1°F (-0.5°C).

Temperature

In Keystone, West Virginia, the average high-temperature marginally drops, from a fresh 52.5°F (11.4°C) in November, to a chilly 44.4°F (6.9°C). In Keystone, West Virginia, in December, the average low-temperature is 31.1°F (-0.5°C).

Humidity

In December, the average relative humidity in Keystone is 81%.

Rainfall

In December, in Keystone, the rain falls for 11.6 days. Throughout December, 2.8" (71mm) of precipitation is accumulated. In Keystone, during the entire year, the rain falls for 172.5 days and collects up to 29.41" (747mm) of precipitation.

Snowfall

Months with snowfall are January through May, October through December. December is the month with the most snowfall. Snow falls for 7.8 days and accumulates 4.41" (112mm) of snow.

Daylight

December has the shortest days of the year in Keystone, with an average of 9.6h of daylight.

Sunshine

The average sunshine in Keystone is 4.7h.

UV index

Months with the lowest UV index in Keystone are January, February and December, with an average maximum UV index of 2. A UV Index of 2, and less, symbolizes a minimal health vulnerability from unsafe exposure to the UV radiation for ordinary individuals.
Note: The average daily UV index of 2 in December transform into the following instructions:
Extended sun exposure is not an issue for the majority. Children, infants, and fair-skinned individuals always need to be protected. The solar radiation is most powerful near the mid-day, so the exposure to the direct Sun should be reduced accordingly. Sun-protective clothing, a long-sleeved shirt and pants, a wide-brimmed hat, and UVA and UVB-blocking sunglasses are particularly helpful in blocking UV radiation's harmful effects. Beware! The strength of the UV rays is increased nearly double-fold by the reflection of the snow.
[Resources]

FAQ

What is the average humidity in December in Keystone?

In December, the average relative humidity in Keystone is 81%.

How much does it rain in Keystone in December?

In Keystone, in December, during 11.6 rainfall days, 2.8" (71mm) of precipitation is typically accumulated.

When does it snow the most in Keystone?

The month with the most snowfall is December when snow falls for 7.8 days and typically aggregates up to 4.41" (112mm) of snow.

How much does it snow in Keystone in December?

In Keystone, in December, during 7.8 snowfall days, 4.41" (112mm) of snow is typically accumulated.

What is the month with the shortest days in Keystone?

The month with the shortest days in Keystone, West Virginia, is December, with an average of 9.6h of daylight.

How many hours of daylight does Keystone have in December?

In December, the average length of the day in Keystone is 9.6h.

How many hours of sunshine does Keystone have in December?

In Keystone, West Virginia, the average sunshine in December is 4.7h.

When is the lowest UV index in Keystone?

January, February and December, with an average maximum UV index of 2, are months with the lowest UV index in Keystone.

What is the UV index intensity in December in Keystone?

In Keystone, the average daily maximum UV index in December is 2. A UV Index value of 2, and less, symbolizes a low health risk from unprotected exposure to the UV radiation.

Average temperature in December
Keystone, West VA

Average temperature in December - Keystone, West VA
  • Average high temperature in December: 44.4°F

The warmest month (with the highest average high temperature) is July (83.5°F).
The month with the lowest average high temperature is January (39.2°F).

  • Average low temperature in December: 31.1°F

The month with the highest average low temperature is July (60.3°F).
The coldest month (with the lowest average low temperature) is January (25°F).

[Resources]

Average pressure in December
Keystone, West VA

Average pressure in December - Keystone, West VA
  • Average pressure in December: 30.14"

The month with the highest atmospheric pressure is November (30.16").
The month with the lowest atmospheric pressure is June (29.99").

[Resources]

Average wind speed in December
Keystone, West VA

Average wind speed in December - Keystone, West VA
  • Average wind speed in December: 6.5mph

The windiest month (with the highest average wind speed) is January (7.3mph).
The calmest month (with the lowest average wind speed) is August (4.2mph).

[Resources]

Average humidity in December
Keystone, West VA

Average humidity in December - Keystone, West VA
  • Average humidity in December: 81%

The month with the highest relative humidity is February (82%).
Months with the lowest relative humidity are July, August and November (76%).

[Resources]

Average rainfall in December
Keystone, West VA

Average rainfall in December - Keystone, West VA
  • Average rainfall in December: 2.8"

The wettest month (with the highest rainfall) is May (3.19").
The driest month (with the least rainfall) is September (1.54").

[Resources]

Average rainfall days in December
Keystone, West VA

Average rainfall days in December - Keystone, West VA
  • Average rainfall days in December: 11.6 days

The month with the highest number of rainy days is May (19.7 days).
Months with the least rainy days are January and November (10.1 days).

[Resources]

Average snowfall in December
Keystone, West VA

Average snowfall in December - Keystone, West VA
  • Average snowfall in December: 4.41"

The month with the highest snowfall is December (4.41").
Months with the least snowfall are June, July, August and September (0").

[Resources]

Average snowfall days in December
Keystone, West VA

Average snowfall days in December - Keystone, West VA
  • Average snowfall days in December: 7.8 days

The month with the highest number of snowfall days is January (10.5 days).
Months with the least snowfall days are June, July, August and September (0 days).

[Resources]

Average daylight in December /
Average sunshine in December
Keystone, West VA

Average daylight in December / Average sunshine in December - Keystone, West VA
  • Average daylight in December: 9.6h

The month with the longest days is June (Average daylight: 14.7h).
The month with the shortest days is December (Average daylight: 9.6h).

  • Average sunshine in December: 4.7h

The month with the most sunshine is August (Average sunshine: 10.1h).
The month with the least sunshine is January (Average sunshine: 4.2h).

[Resources]

Average sunshine days in December
Keystone, West VA

Average sunshine days in December - Keystone, West VA
  • Average sunshine days in December: 13.8 days

The month with the most sunshine days is November (17.9 days).
The month with the least sunshine days is May (9.2 days).

[Resources]

Average UV index in December
Keystone, West VA

Average UV index in December - Keystone, West VA
  • Average UV index in December: 2

Months with the highest UV index are June and August (UV index 6).
Months with the lowest UV index are January, February and December (UV index 2).

[Resources]

Average cloud cover in December
Keystone, West VA

Average cloud cover in December - Keystone, West VA
  • Average cloud cover in December: 55

The month with the most cloud cover is January (Cloud cover 60).
Months with the least cloud cover are June and August (Cloud cover 36).

[Resources]

Average visibility in December
Keystone, West VA

Average visibility in December - Keystone, West VA
  • Average visibility in December: 5mi

Months with the highest visibility are April and November (6mi).
Months with the lowest visibility are January, February, March, May, June, July, August, September, October and December (5mi).

[Resources]

Weather forecast for your location

1. Click Locate me button
2. Allow the app to use your location
* you will be automatically redirected to the weather forecast for your location