December weather forecast
Hillsdale, NJ

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Weather in December

December, the first month of the winter in Hillsdale, is still a cold month, with an average temperature varying between 30.4°F (-0.9°C) and 40.8°F (4.9°C).

Temperature

As December commences, the average high-temperature shows a reduction, transitioning from a fresh 50.7°F (10.4°C) in November to a cold 40.8°F (4.9°C). Hillsdale's nighttime temperature in December drops 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.

Rainfall

December is the month with the most rainfall in Hillsdale. Rain falls for 10.6 days and accumulates 3.58" (91mm) of precipitation.

Snowfall

January through April, October through December are months with snowfall. In December, it is snowing for 4.5 days. Throughout December, 2.05" (52mm) of snow is accumulated. In Hillsdale, during the entire year, snow falls for 28 days and aggregates up to 13.82" (351mm) of snow.

Daylight

With an average of 9h and 18min of daylight, December has the shortest days of the year in Hillsdale, New Jersey.
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, in Hillsdale, sunrise is at 7:20 am and sunset at 4:38 pm EST.

Sunshine

In Hillsdale, 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 in Hillsdale. A UV Index of 2, and less, symbolizes a minimal health vulnerability from exposure to the Sun's UV radiation for ordinary individuals.
Note: In December, the maximum UV index of 2 suggests this advice:
In contrast to children, who must always be shielded from the sun, most people can tolerate up to an hour of sun exposure without any burns. Avoiding direct sun during mid-day hours can prevent harmful UV radiation exposure. Protect your eyes, ears, face, and neck from the Sun by wearing a wide-brimmed hat. Be watchful! The reflection of snow can enhance the intensity of the Sun's UV radiation nearly double.
Updated: Feb 13, 2024
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate

Frequently asked questions

How cold does it get in Hillsdale in December?

In Hillsdale, in December, the average high-temperature is 40.8°F (4.9°C), and the average low-temperature is 30.4°F (-0.9°C). The average heat index (a.k.a. 'feels like', 'felt air temperature'), which represents the influence of relative humidity on air temperature, in August is appraised at 87.8°F (31°C).

What are the most humid months in Hillsdale?

The months with the highest humidity in Hillsdale, New Jersey, are February and December, with an average relative humidity of 78%.

What is the average humidity in December in Hillsdale?

In December, the average relative humidity is 78%.

What is the rainiest month in Hillsdale?

December is the month with the most rainfall in Hillsdale. Rain falls for 10.6 days and accumulates 3.58" (91mm) of precipitation.

How many days does it rain in December in Hillsdale?

In Hillsdale, New Jersey, in December, during 10.6 rainfall days, 3.58" (91mm) of precipitation is typically accumulated.

How many days does it snow in December in Hillsdale?

In Hillsdale, during December, snow falls for 4.5 days and regularly aggregates up to 2.05" (52mm) of snow.

What is the month with the shortest days in Hillsdale?

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

How many hours of daylight does Hillsdale have in December?

The average day length in December is 9h and 17min.

When are sunrise and sunset in December in Hillsdale?

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 7:20 am and sunset at 4:38 pm EST.

How long on average sun shines in December in Hillsdale?

In December, the average sunshine duration in Hillsdale, New Jersey, is 4.7h.

When is the lowest UV index in Hillsdale?

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

How high is the UV index in December in Hillsdale?

The average daily maximum UV index in December in Hillsdale is 2. A UV Index reading of 2, and below, represents 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
Hillsdale, NJ

Average temperature in December - Hillsdale, 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
Hillsdale, NJ

Average pressure in December - Hillsdale, 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
Hillsdale, NJ

Average wind speed in December - Hillsdale, 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
Hillsdale, NJ

Average humidity in December - Hillsdale, 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
Hillsdale, NJ

Average rainfall in December - Hillsdale, 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
Hillsdale, NJ

Average rainfall days in December - Hillsdale, 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
Hillsdale, NJ

Average snowfall in December - Hillsdale, 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
Hillsdale, NJ

Average snowfall days in December - Hillsdale, 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
Hillsdale, NJ

Average daylight in December / Average sunshine in December - Hillsdale, 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
Hillsdale, NJ

Average sunshine days in December - Hillsdale, 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
Hillsdale, NJ

Average UV index in December - Hillsdale, 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
Hillsdale, NJ

Average cloud cover in December - Hillsdale, 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
Hillsdale, NJ

Average visibility in December - Hillsdale, 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).

Hillsdale, New Jersey, USA

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