December weather forecast
Allendale, NJ

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Weather in December

December, the first month of the winter in Allendale, is also a wintry month, with an average temperature fluctuating between 40.8°F (4.9°C) and 30.4°F (-0.9°C).

Temperature

Allendale's average high-temperature decreases in December, falling from a fresh 50.7°F (10.4°C) in November to an icy 40.8°F (4.9°C). In December, the nighttime temperature lowers to an average of 30.4°F (-0.9°C).

Humidity

February and December, with an average relative humidity of 78%, are the most humid months in Allendale.

Rainfall

The month with the most rainfall is December, when the rain falls for 10.6 days and typically aggregates up to 3.58" (91mm) of precipitation.

Snowfall

Months with snowfall are January through April, October through December. In Allendale, in December, during 4.5 snowfall days, 2.05" (52mm) of snow is typically accumulated. Throughout the year, there are 28 snowfall days, and 13.82" (351mm) of snow is accumulated.

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 7:02 am and sunset at 4:28 pm. On the last day of December, sunrise is at 7:21 am and sunset at 4:38 pm EST.

Sunshine

In Allendale, the average sunshine in December is 4.7h.

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 low health risk from exposure to the Sun's UV radiation for the average person.
Note: In December, the average maximum UV index of 2 translates into the following recommendations:
Apart from children, who require continuous protection, most can endure sun exposure for up to an hour without experiencing burns. For skin protection, it's recommended to minimize Sun exposure during its peak hours around midday. Boost your sun resistance with garments that are densely woven yet spacious. Be attentive! The reflective property of snow can nearly double the Sun's UV radiation.
Updated: Jul 12, 2024
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate

Frequently asked questions

How cold is December?

The average high-temperature, in December, in Allendale, is 40.8°F (4.9°C), while the average low-temperature is 30.4°F (-0.9°C). The average heat index (a.k.a. 'apparent temperature', 'feels like'), which combines air temperature and relative humidity, in August is computed to be 87.8°F (31°C).

What is the most humid month?

February and December, with an average relative humidity of 78%, are most humid months.

What is the average humidity in December?

The average relative humidity in December is 78%.

What is the rainiest month?

The month with the most rainfall is December, when the rain falls for 10.6 days and typically aggregates up to 3.58" (91mm) of precipitation.

How much does it rain in December?

In Allendale, in December, it is raining for 10.6 days, with typically 3.58" (91mm) of accumulated precipitation.

How much does it snow in December?

In December, it is snowing for 4.5 days. Throughout December, 2.05" (52mm) 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.

What is the average length of the day in December?

In Allendale, the average day length in December is 9h and 17min.

When is the sunrise / sunset in December?

On the first day of December, sunrise is at 7:02 am and sunset at 4:28 pm. On the last day of the month, sunrise is at 7:21 am and sunset at 4:38 pm EST.

How many hours of sunshine does Allendale have in December?

The average sunshine duration in December is 4.7h.

What are the months with the lowest UV index in Allendale?

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 intensity in December?

In December, the average daily maximum UV index is 2. A UV Index reading of 2, and below, represents a low health risk 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
Allendale, NJ

Average temperature in December - Allendale, NJ
  • Average high temperature in December: 40.8°F

The warmest month (with the highest average high temperature) is July (84.7°F).
The month with the lowest average high temperature is January (35.2°F).

  • Average low temperature in December: 30.4°F

The month with the highest average low temperature is July (66.6°F).
The coldest month (with the lowest average low temperature) is January (22.8°F).

Average pressure in December
Allendale, NJ

Average pressure in December - Allendale, NJ
  • Average pressure in December: 30.07"Hg

The month with the highest atmospheric pressure is November (30.1"Hg).
The month with the lowest atmospheric pressure is June (29.93"Hg).

Average wind speed in December
Allendale, NJ

Average wind speed in December - Allendale, NJ
  • Average wind speed in December: 7.3mph

The windiest month (with the highest average wind speed) is March (8mph).
The calmest month (with the lowest average wind speed) is August (5.4mph).

Average humidity in December
Allendale, NJ

Average humidity in December - Allendale, NJ
  • Average humidity in December: 78%

The months with the highest relative humidity are February and December (78%).
The month with the lowest relative humidity is August (70%).

Average rainfall in December
Allendale, NJ

Average rainfall in December - Allendale, NJ
  • Average rainfall in December: 3.58"

The wettest month (with the highest rainfall) is December (3.58").
The driest month (with the least rainfall) is September (1.89").

Average rainfall days in December
Allendale, NJ

Average rainfall days in December - Allendale, NJ
  • Average rainfall days in December: 10.6 days

The months with the highest number of rainy days are May and July (16.8 days).
The month with the least rainy days is January (8.4 days).

Average snowfall in December
Allendale, NJ

Average snowfall in December - Allendale, NJ
  • Average snowfall in December: 2.05"

The month with the highest snowfall is February (4.09").
The months with the least snowfall are May, June, July, August and September (0").

Average snowfall days in December
Allendale, NJ

Average snowfall days in December - Allendale, NJ
  • Average snowfall days in December: 4.5 days

The month with the highest number of snowfall days is February (7.9 days).
The months with the least snowfall days are May, June, July, August and September (0 days).

Average daylight in December /
Average sunshine in December
Allendale, NJ

Average daylight in December / Average sunshine in December - Allendale, NJ
  • Average daylight in December: 9h and 2min

The month with the longest days is June (Average daylight: 15h and 6min).
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 12min).
The month with the least sunshine is February (Average sunshine: 4h and 30min).

Average sunshine days in December
Allendale, NJ

Average sunshine days in December - Allendale, NJ
  • Average sunshine days in December: 16.7 days

The month with the most sunshine days is November (18.7 days).
The month with the least sunshine days is June (11.5 days).

Average UV index in December
Allendale, NJ

Average UV index in December - Allendale, 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
Allendale, NJ

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

The month with the most cloud cover is March (Cloud cover 50).
The month with the least cloud cover is August (Cloud cover 34).

Average visibility in December
Allendale, NJ

Average visibility in December - Allendale, NJ
  • Average visibility in December: 6mi

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

Allendale, New Jersey, USA

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