December weather forecast
Mammoth, PA

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Weather in December

The first month of the winter, December, is still a cold month in Mammoth, Pennsylvania, with temperature in the range of an average low of 27.7°F (-2.4°C) and an average high of 39.2°F (4°C).

Temperature

The arrival of December corresponds with a reduction in the average high-temperature, down from November's chilly 48.9°F (9.4°C) to a wintry 39.2°F (4°C). Mammoth observes an average nighttime temperature of 27.7°F (-2.4°C) during December.

Humidity

In December, the average relative humidity is 84%.

Rainfall

In Mammoth, during December, the rain falls for 13.1 days and regularly aggregates up to 3.03" (77mm) of precipitation. In Mammoth, during the entire year, the rain falls for 185.4 days and collects up to 34.02" (864mm) of precipitation.

Snowfall

January through May, October through December are months with snowfall. In December, in Mammoth, it is snowing for 12.8 days. Throughout December, 6.1" (155mm) of snow is accumulated. In Mammoth, during the entire year, snow falls for 63.2 days and aggregates up to 29.02" (737mm) of snow.

Daylight

The month with the shortest days in Mammoth, Pennsylvania, is December, with an average of 9h and 24min of daylight.
On the first day of December in Mammoth, sunrise is at 7:21 am and sunset at 4:52 pm. On the last day of the month, sunrise is at 7:40 am and sunset at 5:02 pm EST.

Sunshine

In Mammoth, the average sunshine in December is 3.6h.

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 value of 2, and less, symbolizes a low health risk from unsafe exposure to UV radiation for the ordinary person.
Note: In December, an average UV index of 2 transforms into the following instructions:
While most people are not greatly affected by extended sun exposure, those with fair skin, babies, and children must always have protection. Considering the strength of solar radiation at midday, one should avoid direct Sun exposure. For optimum UV protection, wear sun-resistant attire complemented with a hat and quality shades. Mark this! Snow reflection can nearly double the UV radiation intensity from the Sun.

Frequently asked questions

Is it cold in Mammoth during December?

During December, Mammoth experiences an average high-temperature of 39.2°F (4°C) and a low-temperature of 27.7°F (-2.4°C). The average heat index (a.k.a. 'feels like', 'real feel'), which represents the influence of relative humidity on air temperature, in August is computed to be 84.2°F (29°C).

What is the average humidity in December?

In December, the average relative humidity is 84%.

How much does it rain in December?

In December, the rain falls for 13.1 days. Throughout December, 3.03" (77mm) of precipitation is accumulated.

How much does it snow in December?

In Mammoth, during December, snow falls for 12.8 days and regularly aggregates up to 6.1" (155mm) of snow.

What is the month with the shortest days?

December has the shortest days of the year, with an average of 9h and 24min of daylight.

What is the average length of the day in December?

In Mammoth, the average day length in December is 9h and 22min.

When is the sunrise / sunset in December?

In December, on the first day of the month, sunrise is at 7:21 am and sunset at 4:52 pm. On the last day of the month, sunrise is at 7:40 am and sunset at 5:02 pm EST.

How long on average sun shines in December?

In Mammoth, the average sunshine duration in December is 3.6h.

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 in Mammoth.

What is the UV index intensity in December?

In December, the average daily maximum UV index in Mammoth, Pennsylvania, is 2. A UV Index value of 2, and less, symbolizes a low health threat 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
Mammoth, PA

Average temperature in December - Mammoth, PA
  • Average high temperature in December: 39.2°F

The warmest month (with the highest average high temperature) is July (82°F).
The month with the lowest average high temperature is January (33.3°F).

  • Average low temperature in December: 27.7°F

The month with the highest average low temperature is July (60.4°F).
The coldest month (with the lowest average low temperature) is January (20.3°F).

Average pressure in December
Mammoth, PA

Average pressure in December - Mammoth, 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
Mammoth, PA

Average wind speed in December - Mammoth, PA
  • Average wind speed in December: 7.9mph

The windiest month (with the highest average wind speed) is January (8.5mph).
The calmest month (with the lowest average wind speed) is August (4.8mph).

Average humidity in December
Mammoth, PA

Average humidity in December - Mammoth, PA
  • Average humidity in December: 84%

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

Average rainfall in December
Mammoth, PA

Average rainfall in December - Mammoth, PA
  • Average rainfall in December: 3.03"

The wettest month (with the highest rainfall) is May (3.66").
The driest month (with the least rainfall) is November (2.01").

Average rainfall days in December
Mammoth, PA

Average rainfall days in December - Mammoth, PA
  • Average rainfall days in December: 13.1 days

The month with the highest number of rainy days is May (22 days).
The month with the least rainy days is January (9.8 days).

Average snowfall in December
Mammoth, PA

Average snowfall in December - Mammoth, PA
  • Average snowfall in December: 6.1"

The month with the highest snowfall is January (7.09").
The months with the least snowfall are June, July, August and September (0").

Average snowfall days in December
Mammoth, PA

Average snowfall days in December - Mammoth, PA
  • Average snowfall days in December: 12.8 days

The month with the highest number of snowfall days is January (17.3 days).
The months with the least snowfall days are June, July, August and September (0 days).

Average daylight in December /
Average sunshine in December
Mammoth, PA

Average daylight in December / Average sunshine in December - Mammoth, 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 24min).

  • Average sunshine in December: 3h and 4min

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

Average sunshine days in December
Mammoth, PA

Average sunshine days in December - Mammoth, PA
  • Average sunshine days in December: 9.7 days

The month with the most sunshine days is November (13.5 days).
The month with the least sunshine days is January (6.5 days).

Average UV index in December
Mammoth, PA

Average UV index in December - Mammoth, PA
  • Average UV index in December: 2

The month with the highest UV index is July (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
Mammoth, PA

Average cloud cover in December - Mammoth, PA
  • Average cloud cover in December: 64

The month with the most cloud cover is January (Cloud cover 69).
The month with the least cloud cover is August (Cloud cover 35).

Average visibility in December
Mammoth, PA

Average visibility in December - Mammoth, PA
  • Average visibility in December: 5mi

The month with the highest visibility is April (6mi).
The months with the lowest visibility are January and February (4mi).

Mammoth, Pennsylvania, USA

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