December weather forecast
Mamaroneck, NY

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Weather in December

The first month of the winter, December, is also an icy month in Mamaroneck, New York, with an average temperature fluctuating between 32.9°F (0.5°C) and 41.9°F (5.5°C).

Temperature

Start of December brings a shift in the average high-temperature, falling from November's fresh 50.9°F (10.5°C) to a wintry 41.9°F (5.5°C). During the nights of December, Mamaroneck records an average low-temperature of 32.9°F (0.5°C), reflecting a modest decrease from daytime highs.

Humidity

February and December, with an average relative humidity of 75%, are the most humid months.

Rainfall

In Mamaroneck, New York, in December, it is raining for 11.6 days, with typically 2.95" (75mm) of accumulated precipitation. In Mamaroneck, during the entire year, the rain falls for 150.3 days and collects up to 27.72" (704mm) of precipitation.

Snowfall

January through April, November and December are months with snowfall. In Mamaroneck, in December, during 2.5 snowfall days, 1.5" (38mm) of snow is typically accumulated. Throughout the year, in Mamaroneck, New York, there are 18.1 snowfall days, and 8.46" (215mm) of snow is accumulated.

Ocean temperature

In Mamaroneck, the average seawater temperature in December is 48°F (8.9°C).
Note: Swimming in 48°F (8.9°C) poses a severe threat. Even short exposure to 55.4°F (13°C) is chilling, and going below 50°F (10°C) can cause breathing irregularities and intense cold shock, based on one's stamina.

Daylight

The month with the shortest days in Mamaroneck is December, with an average of 9h and 18min of daylight.
On the first day of December in Mamaroneck, New York, sunrise is at 7:00 am and sunset at 4:27 pm. On the last day of the month, sunrise is at 7:19 am and sunset at 4:36 pm EST.

Sunshine

In Mamaroneck, New York, the average sunshine in December is 4.9h.

UV index

January through March, November and December, with an average maximum UV index of 2, are months with the lowest UV index in Mamaroneck. A UV Index reading of 2, and below, represents a minimal health vulnerability from exposure to the Sun's UV radiation for the ordinary person.
Note: In December, the average maximum UV index of 2 translates into the following recommendations:
Those with sensitive skin, infants, and children require constant safeguarding 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. In bright sunlight, prioritize sunglasses that grant protection from UVA and UVB radiation. Warning! The reflection from snow can nearly magnify the Sun's UV radiation twofold.
Updated: Feb 13, 2024
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate

Frequently asked questions

How cold is it in Mamaroneck in December?

The high-temperature in Mamaroneck, New York, during December is 41.9°F (5.5°C) and the low-temperature is 32.9°F (0.5°C). In August, the average heat index (a.k.a. 'real feel', 'feels like'), which represents the influence of relative humidity on air temperature, is appraised at 86°F (30°C).

What is the most humid month in Mamaroneck?

February and December, with an average relative humidity of 75%, are most humid months in Mamaroneck, New York.

What is the average humidity in December in Mamaroneck?

In Mamaroneck, New York, the average relative humidity in December is 75%.

How many days does it rain in December in Mamaroneck?

In Mamaroneck, New York, during December, the rain falls for 11.6 days and regularly aggregates up to 2.95" (75mm) of precipitation.

How much does it snow in Mamaroneck in December?

In Mamaroneck, in December, during 2.5 snowfall days, 1.5" (38mm) of snow is typically accumulated.

What is the water temperature in December in Mamaroneck?

In December, the average ocean temperature in Mamaroneck, New York, is 48°F (8.9°C). Swimming in 48°F (8.9°C) is considered dangerous. Unprotected immersion in temperatures below 50°F (10°C) causes quickly maximum intensity cold shock with hyperventilation.

What is the month with the shortest days in Mamaroneck?

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

How many hours of daylight does Mamaroneck have in December?

In Mamaroneck, New York, the average day length in December is 9h and 17min.

What time are sunrise and sunset in December in Mamaroneck?

On the first day of December, sunrise is at 7:00 am and sunset at 4:27 pm. On the last day of the month, sunrise is at 7:19 am and sunset at 4:36 pm EST.

How long on average sun shines in December in Mamaroneck?

In December, the average sunshine duration in Mamaroneck, New York, is 4.9h.

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

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

How high is the UV index in December in Mamaroneck?

The average daily maximum UV index in December in Mamaroneck, New York, is 2. A UV Index of 2, and less, symbolizes a minimal health vulnerability 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
Mamaroneck, NY

Average temperature in December - Mamaroneck, NY
  • Average high temperature in December: 41.9°F

The warmest month (with the highest average high temperature) is July (82.9°F).
The month with the lowest average high temperature is January (36.3°F).

  • Average low temperature in December: 32.9°F

The month with the highest average low temperature is July (69.4°F).
The coldest month (with the lowest average low temperature) is January (25.9°F).

Average pressure in December
Mamaroneck, NY

Average pressure in December - Mamaroneck, NY
  • 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
Mamaroneck, NY

Average wind speed in December - Mamaroneck, NY
  • Average wind speed in December: 9.4mph

The windiest month (with the highest average wind speed) is January (9.9mph).
The calmest month (with the lowest average wind speed) is July (6.5mph).

Average humidity in December
Mamaroneck, NY

Average humidity in December - Mamaroneck, NY
  • Average humidity in December: 75%

The months with the highest relative humidity are February and December (75%).
The month with the lowest relative humidity is August (70%).

Average rainfall in December
Mamaroneck, NY

Average rainfall in December - Mamaroneck, NY
  • Average rainfall in December: 2.95"

The wettest month (with the highest rainfall) is July (3.23").
The driest months (with the least rainfall) are January and February (1.69").

Average rainfall days in December
Mamaroneck, NY

Average rainfall days in December - Mamaroneck, NY
  • Average rainfall days in December: 11.6 days

The month with the highest number of rainy days is July (17.3 days).
The month with the least rainy days is January (7.3 days).

Average snowfall in December
Mamaroneck, NY

Average snowfall in December - Mamaroneck, NY
  • Average snowfall in December: 1.5"

The month with the highest snowfall is March (2.8").
The months with the least snowfall are May, June, July, August, September and October (0").

Average snowfall days in December
Mamaroneck, NY

Average snowfall days in December - Mamaroneck, NY
  • Average snowfall days in December: 2.5 days

The months with the highest number of snowfall days are January and February (5.3 days).
The months with the least snowfall days are May, June, July, August, September and October (0 days).

Average sea temperature in December
Mamaroneck, NY

Average sea temperature in December - Mamaroneck, NY
  • Average sea temperature in December: 48.1°F

The best month for swimming (with the highest average sea temperature) is August (74.1°F).
The coldest month (with the lowest average sea temperature) is February (39.9°F).

Average daylight in December /
Average sunshine in December
Mamaroneck, NY

Average daylight in December / Average sunshine in December - Mamaroneck, NY
  • 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 5min

The month with the most sunshine is July (Average sunshine: 10h and 42min).
The month with the least sunshine is February (Average sunshine: 4h and 48min).

Average sunshine days in December
Mamaroneck, NY

Average sunshine days in December - Mamaroneck, NY
  • Average sunshine days in December: 17.5 days

The month with the most sunshine days is January (19.6 days).
The month with the least sunshine days is July (12 days).

Average UV index in December
Mamaroneck, NY

Average UV index in December - Mamaroneck, NY
  • 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
Mamaroneck, NY

Average cloud cover in December - Mamaroneck, NY
  • Average cloud cover in December: 47

The months with the most cloud cover are February, March and December (Cloud cover 47).
The month with the least cloud cover is August (Cloud cover 29).

Average visibility in December
Mamaroneck, NY

Average visibility in December - Mamaroneck, NY
  • 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).

Mamaroneck, New York, USA

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