December weather forecast
Grantville, PA

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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.
Updated: Aug 13, 2024
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate

Frequently asked questions

How cold is it in December?

The average high-temperature and low-temperature during December are 39.9°F (4.4°C) and 28.8°F (-1.8°C) respectively. In July, the average heat index (a.k.a. 'felt air temperature', 'real feel'), which represents the influence of relative humidity on air temperature, is estimated at 87.8°F (31°C).

What is the average humidity in December?

The average relative humidity in December is 80%.

How many days does it rain in December?

In Grantville, in December, it is raining for 11 days, with typically 2.68" (68mm) of accumulated precipitation.

How much does it snow in December?

In December, it is snowing for 5.9 days. Throughout December, 1.97" (50mm) of snow is accumulated.

What is the month with the shortest days?

The month with the shortest days is December, with an average of 9h and 18min of daylight.

How many hours of daylight does Grantville have in December?

In Grantville, the average day length in December is 9h and 21min.

What time are sunrise and sunset in December in Grantville?

In December, on the first day of the month, sunrise is at 7:10 am and sunset at 4:40 pm. On the last day of the month, sunrise is at 7:29 am and sunset at 4:50 pm EST.

How many hours of sunshine does Grantville have in December?

In December, the average sunshine duration is 4.4h.

What are the months with the lowest UV index?

January through March, November and December, with an average maximum UV index of 2, are months with the lowest UV index.

What is the UV index intensity in December?

In Grantville, the average daily maximum UV index in December is 2. A UV Index value of 2, and less, symbolizes a minimal hazard to health from unprotected exposure to UV radiation.
Average humidity
Average rainfall days
Average snowfall days
Average daylight
Average sunshine
Average sunshine days
Average UV index
Average cloud cover
Average visibility

Average temperature in December
Grantville, PA

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 - 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 - 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 - 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 - 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 - 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 - 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 - 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 / Average sunshine in December - Grantville, PA
  • Average daylight in December: 9h and 2min

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 2min

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 - 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 - 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 - 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 - 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).

Grantville, Pennsylvania, USA

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