December weather forecastGrantville, PA
December
Weather in December
December, the first month of the winter in Grantville, is also an icy month, with temperature in the range of an average high of 39.9°F (4.4°C) and an average low of 28.8°F (-1.8°C).Temperature
Grantville's average high-temperature decreases in December, falling from a frosty 49.5°F (9.7°C) in November to an icy 39.9°F (4.4°C). Grantville in December experiences a low-temperature average of 28.8°F (-1.8°C).Humidity
In December, the average relative humidity in Grantville is 80%.Rainfall
In Grantville, in December, during 11 rainfall days, 2.68" (68mm) of precipitation is typically accumulated. In Grantville, during the entire year, the rain falls for 166.3 days and collects up to 34.53" (877mm) of precipitation.Snowfall
January through May, October through December are months with snowfall. In December, it is snowing for 5.9 days. Throughout December, 1.97" (50mm) of snow is accumulated. In Grantville, during the entire year, snow falls for 32.4 days and aggregates up to 16.69" (424mm) of snow.Daylight
With an average of 9h and 18min of daylight, December has the shortest days of the year.On the first day of the month, sunrise is at 7:10 am and sunset at 4:40 pm. On the last day of December, sunrise is at 7:29 am and sunset at 4:50 pm EST.
Sunshine
In December, the average sunshine is 4.4h.UV index
The months with the lowest UV index are January through March, November and December, with an average maximum UV index of 2. A UV Index reading of 2, and below, represents a minimal health vulnerability from unsafe exposure to UV radiation for ordinary individuals.Note: The maximum daily UV index of 2 in December interprets into the following recommendations:
Apart from children, who require continuous protection, most can endure sun exposure for up to an hour without experiencing burns. Midday Sun has the strongest UV rays, making it crucial to limit exposure and find shade. Your best bet for sun defense on the face, eyes, and neck is a hat with a wide brim. Take careful note! The UV radiation of the Sun can be nearly doubled by snow reflection.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in December
Grantville, PA
- Average high temperature in December: 39.9°F
The warmest month (with the highest average high temperature) is July (82°F).
The month with the lowest average high temperature is January (33.6°F).
- Average low temperature in December: 28.8°F
The month with the highest average low temperature is July (62.4°F).
The coldest month (with the lowest average low temperature) is January (21.2°F).
Average pressure in December
Grantville, PA
- Average pressure in December: 30.1"Hg
The month with the highest atmospheric pressure is November (30.13"Hg).
The month with the lowest atmospheric pressure is June (29.94"Hg).
Average wind speed in December
Grantville, PA
- Average wind speed in December: 7.8mph
The windiest month (with the highest average wind speed) is March (8.7mph).
The calmest month (with the lowest average wind speed) is August (4.8mph).
Average humidity in December
Grantville, PA
- Average humidity in December: 80%
The months with the highest relative humidity are February, May, June and October (81%).
The month with the lowest relative humidity is April (76%).
Average rainfall in December
Grantville, PA
- Average rainfall in December: 2.68"
The wettest months (with the highest rainfall) are May and July (3.58").
The driest month (with the least rainfall) is September (2.32").
Average rainfall days in December
Grantville, PA
- Average rainfall days in December: 11 days
The month with the highest number of rainy days is May (18.6 days).
The month with the least rainy days is January (9.1 days).
Average snowfall in December
Grantville, PA
- Average snowfall in December: 1.97"
The month with the highest snowfall is January (5.08").
The months with the least snowfall are June, July, August and September (0").
Average snowfall days in December
Grantville, PA
- Average snowfall days in December: 5.9 days
The month with the highest number of snowfall days is January (10.1 days).
The months with the least snowfall days are June, July, August and September (0 days).
Average daylight in December /
Average sunshine in December
Grantville, PA
- Average daylight in December: 9h and 18min
The month with the longest days is June (Average daylight: 15h and 0min).
The month with the shortest days is December (Average daylight: 9h and 18min).
- Average sunshine in December: 4h and 24min
The month with the most sunshine is July (Average sunshine: 10h and 12min).
The month with the least sunshine is February (Average sunshine: 4h and 18min).
Average sunshine days in December
Grantville, PA
- Average sunshine days in December: 14.8 days
The month with the most sunshine days is November (17.5 days).
The month with the least sunshine days is May (10.1 days).
Average UV index in December
Grantville, PA
- Average UV index in December: 2
The month with the highest UV index is June (UV index 6).
The months with the lowest UV index are January, February, March, November and December (UV index 2).
Average cloud cover in December
Grantville, PA
- Average cloud cover in December: 53
The months with the most cloud cover are February and December (Cloud cover 53).
The month with the least cloud cover is July (Cloud cover 33).
Average visibility in December
Grantville, PA
- Average visibility in December: 5mi
The months with the highest visibility are March, April, June, July and November (6mi).
The months with the lowest visibility are January, February, May, August, September, October and December (5mi).





