December weather forecast and climate
Somerville, NJ

December, the first month of the winter, in Somerville, is also a wintry month, with average temperature varying between 42.3°F (5.7°C) and 30.6°F (-0.8°C).

Temperature

In December, the average high-temperature slightly decreases, from a fresh 50.9°F (10.5°C) in November, to a cold 42.3°F (5.7°C). In Somerville, the average low-temperature is 30.6°F (-0.8°C).

Humidity

Months with the highest humidity are February, October and December, with an average relative humidity of 79%.

Rainfall

December is the month with the most rainfall in Somerville, New Jersey. Rain falls for 10.9 days and accumulates 2.91" (74mm) of precipitation.

Snowfall

January through May, October through December are months with snowfall in Somerville. In Somerville, New Jersey, during 4 snowfall days, 1.46" (37mm) of snow is typically accumulated. In Somerville, during the entire year, snow falls for 23.8 days, and aggregates up to 9.53" (242mm) of snow.

Daylight

With an average of 9.3h of daylight, December has the shortest days of the year in Somerville.

Sunshine

The average sunshine in Somerville is 4.8h.

UV index

January through March, November and December, with an average maximum UV index of 2, are months with the lowest UV index in Somerville. A UV Index estimate of 2, and below, represents a low threat to health from unsafe exposure to the UV radiation for the ordinary person.
Note: In December, the average maximum UV index of 2 translate into the following recommendations:
People with sensitive skin, children, and babies should always be protected from prolonged sun exposure. The solar radiation is most powerful near the mid-day, so the exposure to the direct Sun should be reduced accordingly. Sun-protective clothing, a long-sleeved shirt and pants, a wide-brimmed hat, and UVA and UVB-blocking sunglasses are particularly helpful in blocking UV radiation's harmful effects. Beware! The strength of the UV rays is increased nearly double-fold by the reflection of the snow.

What is the temperature in December in Somerville?

In December, in Somerville, New Jersey, the average high-temperature is 42.3°F (5.7°C), and the average low-temperature is 30.6°F (-0.8°C).

What are the most humid months in Somerville?

Months with the highest humidity in Somerville, New Jersey, are February, October and December, with an average relative humidity of 79%.

What is the average humidity in December in Somerville?

The average relative humidity in December is 79%.

How much does it rain in Somerville in December?

In December, in Somerville, New Jersey, the rain falls for 10.9 days. Throughout December, 2.91" (74mm) of precipitation is accumulated.

What is the wettest month in Somerville?

December is the month with the most rainfall in Somerville, New Jersey. Rain falls for 10.9 days and accumulates 2.91" (74mm) of precipitation.

How many days does it snow in December in Somerville?

In Somerville, during December, snow falls for 4 days and regularly aggregates up to 1.46" (37mm) of snow.

What is the month with the shortest days in Somerville?

With an average of 9.3h of daylight, December has the shortest days of the year in Somerville, New Jersey.

How many hours of daylight does Somerville have in December?

The average length of the day in December in Somerville, New Jersey, is 9.3h.

How long on average sun shines in December in Somerville?

In Somerville, the average sunshine in December is 4.8h.

What is the month with the lowest UV index in Somerville?

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

What is the UV index reading in December in Somerville?

The average daily maximum UV index in December in Somerville, New Jersey, is 2. A UV Index reading of 2, and below, represents a low health threat from unsafe exposure to the Sun's UV rays.
Average temperature in December - Somerville, NJ
  • Average high temperature in December: 5.7°C

The warmest month (with the highest average high temperature) is July (29°C).
The month with the lowest average high temperature is January (2°C).

  • Average low temperature in December: -0.8°C

The month with the highest average low temperature is July (18.9°C).
The coldest month (with the lowest average low temperature) is January (-4.9°C).

Average pressure in December - Somerville, NJ
  • Average pressure in December: 1018.7mbar

The month with the highest atmospheric pressure is November (1019.7mbar).
The month with the lowest atmospheric pressure is June (1013.7mbar).

Average wind speed in December - Somerville, NJ
  • Average wind speed in December: 12.5km/h

The windiest month (with the highest average wind speed) is March (13.9km/h).
The calmest month (with the lowest average wind speed) is August (8.6km/h).

Average humidity in December - Somerville, NJ
  • Average humidity in December: 79%

Months with the highest relative humidity are February, October and December (79%).
The month with the lowest relative humidity is April (74%).

Average rainfall in December - Somerville, NJ
  • Average rainfall in December: 74mm

The wettest month (with the highest rainfall) is December (74mm).
The driest month (with the least rainfall) is September (39mm).

Average rainfall days in December - Somerville, NJ
  • Average rainfall days in December: 10.9 days

The month with the highest number of rainy days is May (17 days).
The month with the least rainy days is February (9 days).

Average snowfall in December - Somerville, NJ
  • Average snowfall in December: 37mm

The month with the highest snowfall is March (72mm).
Months with the least snowfall are June, July, August and September (0mm).

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

The month with the highest number of snowfall days is January (6.8 days).
Months with the least snowfall days are June, July, August and September (0 days).

Average daylight in December / Average sunshine in December - Somerville, NJ
  • Average daylight in December: 9.3h

The month with the longest days is June (Average daylight: 15h).
The month with the shortest days is December (Average daylight: 9.3h).

  • Average sunshine in December: 4.8h

The month with the most sunshine is July (Average sunshine: 10.4h).
The month with the least sunshine is February (Average sunshine: 4.6h).

Average sunshine days in December - Somerville, NJ
  • Average sunshine days in December: 16.3 days

The month with the most sunshine days is November (19.3 days).
The month with the least sunshine days is June (11.7 days).

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

Months with the highest UV index are June, July and August (UV index 6).
Months with the lowest UV index are January, February, March, November and December (UV index 2).

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

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

Average visibility in December - Somerville, NJ
  • Average visibility in December: 9km

Months with the highest visibility are January, February, March, April, June, July, August, October, November and December (9km).
Months with the lowest visibility are May and September (8km).