December weather forecastRumson, NJ

December

Weather in December

The first month of the winter, December, is also a frosty month in Rumson, New Jersey, with temperature in the range of an average low of 36°F (2.2°C) and an average high of 44.2°F (6.8°C).

Temperature

December's arrival comes with a mild decrease in the average high-temperature, moving subtly from a fresh 52.3°F (11.3°C) in November to a chilly 44.2°F (6.8°C). A modest decline from daytime high temperatures in Rumson is noticed in December, marking the average low at an icy 36°F (2.2°C).

Humidity

In December, the average relative humidity is 75%.

Rainfall

In Rumson, during December, the rain falls for 9.2 days and regularly aggregates up to 1.18" (30mm) of precipitation. Throughout the year, there are 125.1 rainfall days, and 12.64" (321mm) of precipitation is accumulated.

Snowfall

Months with snowfall in Rumson are January through March, October and December. December is the month with the most snowfall. Snow falls for 3.3 days and accumulates 0.47" (12mm) of snow.

Ocean temperature

In Rumson, in December, the average water temperature is 48.2°F (9°C).
Note: Taking a dip in 48.2°F (9°C) can be perilous. Submersion in temperatures under 50°F (10°C) triggers severe cold shock accompanied by hyperventilation.

Daylight

With an average of 9h and 18min of daylight, December has the shortest days of the year in Rumson.
On the first day of the month, sunrise is at 7:00 am and sunset at 4:30 pm. On the last day of December, in Rumson, sunrise is at 7:18 am and sunset at 4:39 pm EST.

Sunshine

The average sunshine in December is 5.1h.

UV index

January, February, 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 unsafe exposure to UV radiation for the average person.
Note: A daily maximum UV index of 2 in December translates into the following instructions:
Unlike children, who always need sun protection, most individuals can remain in the sun for up to an hour without getting burnt. Limiting exposure to the direct Sun during midday hours can help prevent harmful UV radiation effects. For optimum UV protection, wear sun-resistant attire complemented with a hat and quality shades. Take careful note! The UV radiation of the Sun can be nearly doubled by snow reflection.

Updated: Feb 13, 2024
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate

Frequently asked questions

The high-temperature in Rumson, New Jersey, during December is 44.2°F (6.8°C) and the low-temperature is 36°F (2.2°C).

In Rumson, New Jersey, the average relative humidity in December is 75%.

In December, the rain falls for 9.2 days. Throughout December, 1.18" (30mm) of precipitation is accumulated.

The month with the most snowfall in Rumson, New Jersey, is December, when snow falls for 3.3 days and typically aggregates up to 0.47" (12mm) of snow.

December is the first month it typically snows in Rumson, New Jersey. Throughout December, in the average 3.3 snowfall days, it receives 0.47" (12mm) of snow.

In December, the average ocean temperature is 48.2°F (9°C). Swimming in 48.2°F (9°C) is considered life-threatening. Even a few minutes in 55.4°F (13°C) water is uncomfortable, and swimming below 50°F (10°C) may cause total loss of breathing control and cold shock, depending on a person's physique.

The month with the shortest days is December, with an average of 9h and 18min of daylight.

In December, the average day length in Rumson, New Jersey, is 9h and 21min.

On the first day of December in Rumson, New Jersey, sunrise is at 7:00 am and sunset at 4:30 pm. On the last day of the month, sunrise is at 7:18 am and sunset at 4:39 pm EST.

In December, the average sunshine duration is 5.1h.

January, February, November and December, with an average maximum UV index of 2, are months with the lowest UV index in Rumson.

In Rumson, the average daily maximum UV index in December is 2. A UV Index reading of 2, and below, represents a low health risk from unprotected exposure to UV radiation.

Today

Tomorrow

Long-term

Year J F M A M J J A S O N December

Nov

December

Jan

Average high temperature

52.3°F

44.2°F

37.9°F

Average low temperature

Average pressure

Average wind speed

Average max. wind speed

12.3mph

12.5mph

13.1mph

Average wind speed gusts

Average humidity

Average rainfall

Average rainfall days

Average snowfall

Average snowfall days

0.3

3.3

3.9

Average sea temperature

Average daylight

Average sunshine

Average sunshine days

21.6

19.1

21.2

Average UV index

Average cloud cover

Average visibility

Average temperature in December
Rumson, NJ

Average high temperature in December: 44.2°F

The warmest month (with the highest average high temperature) is July (80.2°F).
The month with the lowest average high temperature is January (37.9°F).

Average low temperature in December: 36°F

The month with the highest average low temperature is July (71.2°F).
The coldest month (with the lowest average low temperature) is January (28.8°F).

Average pressure in December
Rumson, 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
Rumson, NJ

Average wind speed in December: 11.7mph

The windiest month (with the highest average wind speed) is January (12.4mph).
The calmest month (with the lowest average wind speed) is July (7.9mph).

Average humidity in December
Rumson, NJ

Average humidity in December: 75%

The months with the highest relative humidity are May and June (79%).
The month with the lowest relative humidity is November (73%).

Average rainfall in December
Rumson, NJ

Average rainfall in December: 1.18"

The wettest month (with the highest rainfall) is July (1.61").
The driest month (with the least rainfall) is January (0.63").

Average rainfall days in December
Rumson, NJ

Average rainfall days in December: 9.2 days

The month with the highest number of rainy days is July (15.1 days).
The month with the least rainy days is January (6.5 days).

Average snowfall in December
Rumson, NJ

Average snowfall in December: 0.47"

The month with the highest snowfall is December (0.47").
The months with the least snowfall are April, May, June, July, August, September and November (0").

Average snowfall days in December
Rumson, NJ

Average snowfall days in December: 3.3 days

The month with the highest number of snowfall days is January (3.9 days).
The months with the least snowfall days are April, May, June, July, August and September (0 days).

Average sea temperature in December
Rumson, NJ

Average sea temperature in December: 48.2°F

The best month for swimming (with the highest average sea temperature) is August (74.5°F).
The coldest month (with the lowest average sea temperature) is February (40.1°F).

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

Average daylight in December: 9h and 18min

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: 5h and 6min

The month with the most sunshine is July (Average sunshine: 10h and 48min).
The month with the least sunshine is February (Average sunshine: 4h and 54min).

Average sunshine days in December
Rumson, NJ

Average sunshine days in December: 19.1 days

The month with the most sunshine days is November (21.6 days).
The month with the least sunshine days is July (13 days).

Average UV index in December
Rumson, 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, November and December (UV index 2).

Average cloud cover in December
Rumson, NJ

Average cloud cover in December: 46

The month with the most cloud cover is February (Cloud cover 47).
The months with the least cloud cover are July and August (Cloud cover 28).

Average visibility in December
Rumson, NJ

Average visibility in December: 6mi

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