December weather forecast
Mountainville, NJ

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Weather in December

December, the first month of the winter in Mountainville, is still a cold month, with an average temperature fluctuating between 29.3°F (-1.5°C) and 41°F (5°C).

Temperature

As Mountainville, New Jersey, enters December, the average high-temperature decreases from the a cool 50.4°F (10.2°C) of November to an icy 41°F (5°C). The mean low-temperature during December nights is a freezing cold 29.3°F (-1.5°C).

Humidity

February, October and December, with an average relative humidity of 80%, are the most humid months.

Rainfall

The month with the most rainfall is December, when the rain falls for 12.3 days and typically aggregates up to 3.35" (85mm) of precipitation.

Snowfall

Months with snowfall are January through May, October through December. In Mountainville, in December, snow falls for 4 days, with typically accumulated 2.32" (59mm) of snow. In Mountainville, during the entire year, snow falls for 27.8 days and aggregates up to 15.35" (390mm) 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 7:04 am and sunset at 4:32 pm. On the last day of December, sunrise is at 7:23 am and sunset at 4:42 pm EST.

Sunshine

In December, the average sunshine in Mountainville is 4.9h.

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 of 2, and less, symbolizes a minimal health hazard from exposure to the Sun's UV radiation for the ordinary person.
Note: An average maximum UV index of 2 in December leads to these recommendations:
Infants, children, and people with sensitive skin should always have protection against lengthy periods of sun exposure. Direct Sun exposure should be minimized especially during midday when radiation is most intense. A hat with a generous brim can prevent nearly 50% of UV rays from reaching your eyes. Beware! Reflection from snow can magnify the Sun's UV radiation nearly twofold.
Updated: Jul 22, 2024
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate

Frequently asked questions

Is it cold during December?

The high-temperature, in December, in Mountainville, records 41°F (5°C), while the low-temperature is 29.3°F (-1.5°C). The average heat index (a.k.a. 'felt air temperature', 'real feel'), which factors the actual air temperature with the relative humidity, in August is computed to be 87.8°F (31°C).

What is the most humid month in Mountainville?

February, October and December, with an average relative humidity of 80%, are most humid months.

What is the average humidity in December?

The average relative humidity in December in Mountainville is 80%.

What is the wettest month in Mountainville?

The month with the most rainfall is December, when the rain falls for 12.3 days and typically aggregates up to 3.35" (85mm) of precipitation.

How much does it rain in December?

In December, the rain falls for 12.3 days. Throughout December, 3.35" (85mm) of precipitation is accumulated.

How many days does it snow in December?

In Mountainville, in December, during 4 snowfall days, 2.32" (59mm) of snow is typically accumulated.

What is the month with the shortest days?

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

How many hours of daylight does Mountainville have in December?

The average day length in December is 9h and 19min.

When is the sunrise / sunset in December?

In December, on the first day of the month, sunrise is at 7:04 am and sunset at 4:32 pm. On the last day of the month, sunrise is at 7:23 am and sunset at 4:42 pm EST.

How long on average sun shines in December?

In December, the average sunshine duration is 4.9h.

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.

How high is the UV index in December?

In Mountainville, the average daily maximum UV index in December is 2. A UV Index of 2, and less, symbolizes a minimal hazard to health from 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
Mountainville, NJ

Average temperature in December - Mountainville, NJ
  • Average high temperature in December: 41°F

The warmest month (with the highest average high temperature) is July (83.8°F).
The month with the lowest average high temperature is January (35.1°F).

  • Average low temperature in December: 29.3°F

The month with the highest average low temperature is July (64°F).
The coldest month (with the lowest average low temperature) is January (22.3°F).

Average pressure in December
Mountainville, NJ

Average pressure in December - Mountainville, NJ
  • Average pressure in December: 30.09"Hg

The month with the highest atmospheric pressure is November (30.11"Hg).
The month with the lowest atmospheric pressure is June (29.93"Hg).

Average wind speed in December
Mountainville, NJ

Average wind speed in December - Mountainville, NJ
  • Average wind speed in December: 7.5mph

The windiest month (with the highest average wind speed) is March (8.3mph).
The calmest month (with the lowest average wind speed) is August (5mph).

Average humidity in December
Mountainville, NJ

Average humidity in December - Mountainville, NJ
  • Average humidity in December: 80%

The months with the highest relative humidity are February, October and December (80%).
The month with the lowest relative humidity is April (75%).

Average rainfall in December
Mountainville, NJ

Average rainfall in December - Mountainville, NJ
  • Average rainfall in December: 3.35"

The wettest month (with the highest rainfall) is December (3.35").
The driest month (with the least rainfall) is September (1.89").

Average rainfall days in December
Mountainville, NJ

Average rainfall days in December - Mountainville, NJ
  • Average rainfall days in December: 12.3 days

The month with the highest number of rainy days is July (17.6 days).
The month with the least rainy days is January (8.8 days).

Average snowfall in December
Mountainville, NJ

Average snowfall in December - Mountainville, NJ
  • Average snowfall in December: 2.32"

The month with the highest snowfall is March (4.76").
The months with the least snowfall are June, July, August and September (0").

Average snowfall days in December
Mountainville, NJ

Average snowfall days in December - Mountainville, NJ
  • Average snowfall days in December: 4 days

The months with the highest number of snowfall days are January and February (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
Mountainville, NJ

Average daylight in December / Average sunshine in December - Mountainville, NJ
  • 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 5min

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 36min).

Average sunshine days in December
Mountainville, NJ

Average sunshine days in December - Mountainville, NJ
  • Average sunshine days in December: 16.2 days

The month with the most sunshine days is November (17.5 days).
The month with the least sunshine days is June (11 days).

Average UV index in December
Mountainville, NJ

Average UV index in December - Mountainville, NJ
  • Average UV index in December: 2

The months with the highest UV index are June, July and August (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
Mountainville, NJ

Average cloud cover in December - Mountainville, NJ
  • Average cloud cover in December: 49

The months with the most cloud cover are February and December (Cloud cover 49).
The months with the least cloud cover are July and August (Cloud cover 34).

Average visibility in December
Mountainville, NJ

Average visibility in December - Mountainville, NJ
  • 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).

Mountainville, New Jersey, USA

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