December weather forecast
Mount Aetna, PA

Share

Weather in December

The first month of the winter, December, is still a cold month in Mount Aetna, Pennsylvania, with temperature in the range of an average high of 40.5°F (4.7°C) and an average low of 29.3°F (-1.5°C).

Temperature

The transition into December involves a small decrease in the average high-temperature, dipping slightly from a chilly 49.5°F (9.7°C) in November to a cold 40.5°F (4.7°C). The mean low-temperature during December nights is a freezing cold 29.3°F (-1.5°C).

Humidity

The average relative humidity in December in Mount Aetna is 80%.

Rainfall

In Mount Aetna, during December, the rain falls for 11.5 days and regularly aggregates up to 2.72" (69mm) of precipitation. In Mount Aetna, during the entire year, the rain falls for 168.8 days and collects up to 33.27" (845mm) of precipitation.

Snowfall

Months with snowfall are January through May, October through December. In December, it is snowing for 5.4 days. Throughout December, 1.97" (50mm) of snow is accumulated. Throughout the year, there are 29.6 snowfall days, and 15.59" (396mm) of snow is accumulated.

Daylight

December has the shortest days of the year, with an average of 9h and 18min of daylight.
On the first day of the month, sunrise is at 7:09 am and sunset at 4:39 pm. On the last day of December, sunrise is at 7:28 am and sunset at 4:48 pm EST.

Sunshine

In December, the average sunshine is 4.6h.

UV index

January through March, November and December, with an average maximum UV index of 2, are months with the lowest UV index. A UV Index estimate of 2, and below, represents a minimal health vulnerability from unsafe exposure to UV radiation for ordinary individuals.
Note: In December, the average maximum UV index of 2 translates into the following recommendations:
Children necessitate constant protection from sunlight, unlike the majority, who can remain under the sun for about an hour without burning. The Sun is at its harshest during midday; protect yourself by staying in shaded areas and minimizing exposure. During bright days, sunglasses that offer UVA and UVB defense are recommended. Heads up! The UV radiation from the Sun can almost be doubled by snow reflection.
Updated: Aug 24, 2024
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate

Frequently asked questions

How cold does it get in December?

In Mount Aetna, in December, the average high-temperature is 40.5°F (4.7°C), and the average low-temperature is 29.3°F (-1.5°C). The average heat index (a.k.a. 'apparent temperature', 'real feel'), which combines air temperature and relative humidity, in July is evaluated at 89.6°F (32°C).

What is the average humidity in December?

In Mount Aetna, the average relative humidity in December is 80%.

How many days does it rain in December?

In Mount Aetna, in December, during 11.5 rainfall days, 2.72" (69mm) of precipitation is typically accumulated.

How much does it snow in December?

In Mount Aetna, Pennsylvania, during December, snow falls for 5.4 days and regularly aggregates up to 1.97" (50mm) of snow.

What is the month with the shortest days?

December has the shortest days of the year in Mount Aetna, Pennsylvania, with an average of 9h and 18min of daylight.

How many hours of daylight does Mount Aetna have in December?

The average day length in December in Mount Aetna is 9h and 20min.

When is the sunrise / sunset in December?

In December, on the first day of the month, sunrise is at 7:09 am and sunset at 4:39 pm. On the last day of the month, sunrise is at 7:28 am and sunset at 4:48 pm EST.

How long on average sun shines in December?

In December, the average sunshine duration is 4.6h.

When is the lowest UV index?

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

What is the UV index reading in December?

In Mount Aetna, the average daily maximum UV index in December is 2. A UV Index of 2, and less, symbolizes a low health risk from unsafe exposure to Sun's UV rays.
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
Mount Aetna, PA

Average temperature in December - Mount Aetna, PA
  • Average high temperature in December: 40.5°F

The warmest month (with the highest average high temperature) is July (82.2°F).
The month with the lowest average high temperature is January (33.6°F).

  • Average low temperature in December: 29.3°F

The month with the highest average low temperature is July (63.3°F).
The coldest month (with the lowest average low temperature) is January (21.7°F).

Average pressure in December
Mount Aetna, PA

Average pressure in December - Mount Aetna, 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
Mount Aetna, PA

Average wind speed in December - Mount Aetna, PA
  • Average wind speed in December: 8mph

The windiest month (with the highest average wind speed) is March (8.8mph).
The calmest month (with the lowest average wind speed) is August (4.8mph).

Average humidity in December
Mount Aetna, PA

Average humidity in December - Mount Aetna, PA
  • Average humidity in December: 80%

The months with the highest relative humidity are February, May and October (81%).
The month with the lowest relative humidity is April (76%).

Average rainfall in December
Mount Aetna, PA

Average rainfall in December - Mount Aetna, PA
  • Average rainfall in December: 2.72"

The wettest month (with the highest rainfall) is August (3.39").
The driest month (with the least rainfall) is September (2.24").

Average rainfall days in December
Mount Aetna, PA

Average rainfall days in December - Mount Aetna, PA
  • Average rainfall days in December: 11.5 days

The month with the highest number of rainy days is May (18.4 days).
The month with the least rainy days is January (9.3 days).

Average snowfall in December
Mount Aetna, PA

Average snowfall in December - Mount Aetna, PA
  • Average snowfall in December: 1.97"

The month with the highest snowfall is March (4.49").
The months with the least snowfall are June, July, August and September (0").

Average snowfall days in December
Mount Aetna, PA

Average snowfall days in December - Mount Aetna, PA
  • Average snowfall days in December: 5.4 days

The month with the highest number of snowfall days is January (9.2 days).
The months with the least snowfall days are June, July, August and September (0 days).

Average daylight in December /
Average sunshine in December
Mount Aetna, PA

Average daylight in December / Average sunshine in December - Mount Aetna, 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 4min

The month with the most sunshine is July (Average sunshine: 10h and 24min).
The month with the least sunshine is February (Average sunshine: 4h and 30min).

Average sunshine days in December
Mount Aetna, PA

Average sunshine days in December - Mount Aetna, PA
  • Average sunshine days in December: 14.9 days

The month with the most sunshine days is November (17.6 days).
The month with the least sunshine days is May (10.2 days).

Average UV index in December
Mount Aetna, PA

Average UV index in December - Mount Aetna, 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
Mount Aetna, PA

Average cloud cover in December - Mount Aetna, PA
  • Average cloud cover in December: 50

The month with the most cloud cover is February (Cloud cover 51).
The month with the least cloud cover is July (Cloud cover 32).

Average visibility in December
Mount Aetna, PA

Average visibility in December - Mount Aetna, PA
  • Average visibility in December: 6mi

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

Mount Aetna, Pennsylvania, USA

Weather forecast for your location

1. Click Locate me button
2. Allow the app to use your location