December weather forecastGreen Hills, PA

December

Weather in December

The first month of the winter, December, is also an icy month in Green Hills, Pennsylvania, with an average temperature varying between 28.6°F (-1.9°C) and 40.1°F (4.5°C).

Temperature

The arrival of December corresponds with a reduction in the average high-temperature, down from November's frosty 49.5°F (9.7°C) to a cold 40.1°F (4.5°C). The month of December records an average low-temperature of 28.6°F (-1.9°C).

Humidity

In December, the average relative humidity is 84%.

Rainfall

In Green Hills, in December, during 9.4 rainfall days, 1.06" (27mm) of precipitation is typically accumulated. In Green Hills, during the entire year, the rain falls for 143 days and collects up to 14.8" (376mm) of precipitation.

Snowfall

January through May, October through December are months with snowfall. In Green Hills, in December, snow falls for 6.5 days, with typically accumulated 0.83" (21mm) of snow. In Green Hills, during the entire year, snow falls for 33.5 days and aggregates up to 4.88" (124mm) of snow.

Daylight

The month with the shortest days is December, with an average of 9h and 24min of daylight.
On the first day of December, sunrise is at 7:24 am and sunset at 4:56 pm. On the last day of the month, sunrise is at 7:43 am and sunset at 5:05 pm EST.

Sunshine

In Green Hills, the average sunshine in December is 3.5h.

UV index

With an average maximum UV index of 1, December is the month with the lowest UV index. A UV Index value of 2, and less, symbolizes a minimal health hazard from unprotected exposure to Sun's UV rays for the average person.
Note: The maximum UV index of 1 during December leads to these instructions:
Children must always have sun protection, unlike most people, who can tolerate up to an hour in the sun without any burns. Considering the Sun's intensity during midday, it's wise to minimize direct exposure. Always opt for UVA and UVB-resistant sunglasses on radiant days. Be cautious! The UV radiation from the Sun can be magnified almost twofold by snow reflection.

Frequently asked questions

In Green Hills, in December, the average high-temperature is 40.1°F (4.5°C), and the average low-temperature is 28.6°F (-1.9°C). The average heat index (a.k.a. 'feels like', 'felt air temperature'), which takes the relative humidity and factors it into the air temperature reading, in August is appraised at 87.8°F (31°C).

The average relative humidity in December is 84%.

In December, the rain falls for 9.4 days. Throughout December, 1.06" (27mm) of precipitation is accumulated.

In Green Hills, in December, snow falls for 6.5 days, with typically accumulated 0.83" (21mm) of snow.

The month with the shortest days in Green Hills is December, with an average of 9h and 24min of daylight.

In Green Hills, Pennsylvania, the average day length in December is 9h and 23min.

On the first day of December, sunrise is at 7:24 am and sunset at 4:56 pm. On the last day of the month, sunrise is at 7:43 am and sunset at 5:05 pm EST.

The average sunshine duration in December is 3.5h.

With an average maximum UV index of 1, December is the month with the lowest UV index.

In December, the average daily maximum UV index is 1. A UV Index value of 2, and less, symbolizes a low health threat from exposure to Sun's UV rays.
Average high temperature
Average low temperature
Average pressure
Average wind speed
Average max. wind speed
Average wind speed gusts
Average humidity
Average rainfall
Average rainfall days
Average snowfall
Average snowfall days
Average daylight
Average sunshine
Average sunshine days
Average UV index
Average cloud cover
Average visibility

Average temperature in December
Green Hills, PA

  • Average high temperature in December: 40.1°F

The warmest month (with the highest average high temperature) is July (83.3°F).
The month with the lowest average high temperature is January (33.6°F).

  • Average low temperature in December: 28.6°F

The month with the highest average low temperature is July (61.9°F).
The coldest month (with the lowest average low temperature) is January (20.8°F).

Average pressure in December
Green Hills, PA

  • Average pressure in December: 30.11"Hg

The month with the highest atmospheric pressure is November (30.14"Hg).
The month with the lowest atmospheric pressure is June (29.95"Hg).

Average wind speed in December
Green Hills, PA

  • Average wind speed in December: 7.1mph

The windiest month (with the highest average wind speed) is January (7.8mph).
The calmest month (with the lowest average wind speed) is August (4.5mph).

Average humidity in December
Green Hills, PA

  • Average humidity in December: 84%

The month with the highest relative humidity is February (85%).
The months with the lowest relative humidity are April, July and August (77%).

Average rainfall in December
Green Hills, PA

  • Average rainfall in December: 1.06"

The wettest month (with the highest rainfall) is July (1.65").
The driest months (with the least rainfall) are January and November (0.94").

Average rainfall days in December
Green Hills, PA

  • Average rainfall days in December: 9.4 days

The month with the highest number of rainy days is May (17.2 days).
The month with the least rainy days is February (7.3 days).

Average snowfall in December
Green Hills, PA

  • Average snowfall in December: 0.83"

The month with the highest snowfall is February (1.26").
The months with the least snowfall are June, July, August and September (0").

Average snowfall days in December
Green Hills, PA

  • Average snowfall days in December: 6.5 days

The month with the highest number of snowfall days is January (9.8 days).
The months with the least snowfall days are June, July, August and September (0 days).

Average daylight in December /
Average sunshine in December
Green Hills, PA

  • Average daylight in December: 9h and 24min

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 24min).

  • Average sunshine in December: 3h and 30min

The month with the most sunshine is August (Average sunshine: 10h and 12min).
The month with the least sunshine is January (Average sunshine: 3h and 0min).

Average sunshine days in December
Green Hills, PA

  • Average sunshine days in December: 17.5 days

The month with the most sunshine days is November (19.1 days).
The month with the least sunshine days is May (11.8 days).

Average UV index in December
Green Hills, PA

  • Average UV index in December: 1

The months with the highest UV index are June, July and August (UV index 6).
The month with the lowest UV index is December (UV index 1).

Average cloud cover in December
Green Hills, PA

  • Average cloud cover in December: 64

The month with the most cloud cover is January (Cloud cover 68).
The month with the least cloud cover is August (Cloud cover 33).

Average visibility in December
Green Hills, PA

  • Average visibility in December: 5mi

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