December weather forecast
Princeton Junction, NJ

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Weather in December

The first month of the winter, December, is still a chilly month in Princeton Junction, New Jersey, with an average temperature ranging between max 43°F (6.1°C) and min 31.1°F (-0.5°C).

Temperature

December's onset brings a negligible change in high-temperatures, falling from a cool 51.8°F (11°C) in November to a frosty 43°F (6.1°C). Princeton Junction in December anticipates an average nighttime temperature of 31.1°F (-0.5°C).

Humidity

In December, the average relative humidity is 78%.

Rainfall

In Princeton Junction, in December, it is raining for 8.2 days, with typically 1.26" (32mm) of accumulated precipitation. In Princeton Junction, New Jersey, during the entire year, the rain falls for 119.3 days and collects up to 12.72" (323mm) of precipitation.

Snowfall

Months with snowfall are January through May, November and December. In Princeton Junction, in December, snow falls for 2.7 days, with typically accumulated 0.75" (19mm) of snow. In Princeton Junction, New Jersey, during the entire year, snow falls for 16.4 days and aggregates up to 4.41" (112mm) 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 the month, sunrise is at 7:02 am and sunset at 4:32 pm. On the last day of December, in Princeton Junction, sunrise is at 7:21 am and sunset at 4:42 pm EST.

Sunshine

The average sunshine in December is 5h.

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 low health risk from unsafe exposure to UV radiation for the average person.
Note: A maximum high UV index of 2 in December translates into the following recommendations:
While many people can endure lengthy sun exposure, it remains imperative to safeguard babies, children, and fair-skinned individuals. Solar radiation is at its peak intensity during midday, so it's advisable to stay indoors or in the shade. A hat with a generous brim can prevent nearly 50% of UV rays from reaching your eyes. Notice this! Nearly double the intensity of the Sun's UV radiation can be caused by snow reflection.
Updated: Aug 24, 2024
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate

Frequently asked questions

Is it cold during December?

During December, Princeton Junction experiences an average high-temperature of 43°F (6.1°C) and a low-temperature of 31.1°F (-0.5°C). The average heat index (a.k.a. 'feels like', 'felt air temperature'), which calculates the temperature value influenced by the moisture in the air, in August is evaluated at 89.6°F (32°C).

What is the average humidity in December?

The average relative humidity in December is 78%.

How many days does it rain in December?

In December, the rain falls for 8.2 days. Throughout December, 1.26" (32mm) of precipitation is accumulated.

How much does it snow in Princeton Junction in December?

In Princeton Junction, in December, during 2.7 snowfall days, 0.75" (19mm) of snow is typically accumulated.

What is the month with the shortest days?

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

What is the average length of the day in December?

In Princeton Junction, the average day length in December is 9h and 21min.

When are sunrise and sunset in December?

On the first day of December, sunrise is at 7:02 am and sunset at 4:32 pm. On the last day of the month, sunrise is at 7:21 am and sunset at 4:42 pm EST.

How long on average sun shines in December?

The average sunshine duration in December is 5h.

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 intensity in December in Princeton Junction?

The average daily maximum UV index in December is 2. A UV Index of 2, and less, symbolizes a minimal hazard to health 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
Princeton Junction, NJ

Average temperature in December - Princeton Junction, NJ
  • Average high temperature in December: 43°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 (36.9°F).

  • Average low temperature in December: 31.1°F

The month with the highest average low temperature is July (66.9°F).
The coldest month (with the lowest average low temperature) is January (24.3°F).

Average pressure in December
Princeton Junction, NJ

Average pressure in December - Princeton Junction, NJ
  • Average pressure in December: 30.08"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
Princeton Junction, NJ

Average wind speed in December - Princeton Junction, NJ
  • Average wind speed in December: 7.8mph

The windiest month (with the highest average wind speed) is March (8.8mph).
The calmest month (with the lowest average wind speed) is August (5.4mph).

Average humidity in December
Princeton Junction, NJ

Average humidity in December - Princeton Junction, NJ
  • Average humidity in December: 78%

The month with the highest relative humidity is October (79%).
The month with the lowest relative humidity is April (73%).

Average rainfall in December
Princeton Junction, NJ

Average rainfall in December - Princeton Junction, NJ
  • Average rainfall in December: 1.26"

The wettest month (with the highest rainfall) is July (1.69").
The driest month (with the least rainfall) is September (0.67").

Average rainfall days in December
Princeton Junction, NJ

Average rainfall days in December - Princeton Junction, NJ
  • Average rainfall days in December: 8.2 days

The month with the highest number of rainy days is July (13.9 days).
The month with the least rainy days is January (6.1 days).

Average snowfall in December
Princeton Junction, NJ

Average snowfall in December - Princeton Junction, NJ
  • Average snowfall in December: 0.75"

The month with the highest snowfall is March (1.42").
The months with the least snowfall are June, July, August, September and October (0").

Average snowfall days in December
Princeton Junction, NJ

Average snowfall days in December - Princeton Junction, NJ
  • Average snowfall days in December: 2.7 days

The month with the highest number of snowfall days is January (4.6 days).
The months with the least snowfall days are June, July, August, September and October (0 days).

Average daylight in December /
Average sunshine in December
Princeton Junction, NJ

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

  • Average sunshine in December: 5h and 0min

The month with the most sunshine is July (Average sunshine: 10h and 30min).
The month with the least sunshine is February (Average sunshine: 4h and 48min).

Average sunshine days in December
Princeton Junction, NJ

Average sunshine days in December - Princeton Junction, NJ
  • Average sunshine days in December: 20.5 days

The month with the most sunshine days is January (21.8 days).
The month with the least sunshine days is July (13.3 days).

Average UV index in December
Princeton Junction, NJ

Average UV index in December - Princeton Junction, 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
Princeton Junction, NJ

Average cloud cover in December - Princeton Junction, NJ
  • Average cloud cover in December: 47

The months with the most cloud cover are February, March and December (Cloud cover 47).
The months with the least cloud cover are July and August (Cloud cover 33).

Average visibility in December
Princeton Junction, NJ

Average visibility in December - Princeton Junction, 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).

Princeton Junction, New Jersey, USA

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