December weather forecast
Sag Harbor, NY

December

Weather in December

December, the first month of the winter in Sag Harbor, is also a frosty month, with an average temperature ranging between min 3.3°C and max 7.2°C.

Temperature

With the onset of December, Sag Harbor experiences a modest temperature adjustment, with the average high-temperature gently receding from a cool 11.5°C in November to a chilly 7.2°C. December nights reflect a consistent temperature dip to a cold 3.3°C, a slight descent from daytime peaks.

Humidity

In December, the average relative humidity is 74%.

Rainfall

The month with the most rainfall is December, when the rain falls for 12.8 days and typically aggregates up to 97mm of precipitation.

Snowfall

Months with snowfall are January through March, November and December. In Sag Harbor, in December, snow falls for 2.3 days, with typically accumulated 23mm of snow. In Sag Harbor, during the entire year, snow falls for 13.9 days and aggregates up to 168mm of snow.

Ocean temperature

In December, the average ocean temperature is 9.9°C.
Note: In 9.9°C, even brief exposure to 13°C feels biting, and anything less than 10°C risks cold shock and impaired breathing, considering one's health.

Daylight

December has the shortest days of the year, with an average of 9h and 18min of daylight.
On the first day of December, sunrise is at 6:55 am and sunset at 4:21 pm. On the last day of the month, sunrise is at 7:13 am and sunset at 4:31 pm EST.

Sunshine

The month with the least sunshine is December, with an average of 4.6h of sunshine.

UV index

The months with the lowest UV index are January through March and December, with an average maximum UV index of 2. A UV Index reading of 2, and below, represents a low health risk from exposure to the Sun's UV radiation for the ordinary person.
Note: A daily high UV index of 2 in December leads to these guidelines:
Many can withstand an hour in the sun without burning, yet children must always have protection against sunlight. Direct exposure to the Sun's intense radiation around midday should be avoided for health reasons. Sun protection is enhanced with clothing that boasts a tight weave yet offers a loose fit. Be alert! Nearly double the UV rays from the Sun can be reflected by snow.
Updated: Jun 15, 2024
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate

Frequently asked questions

What are December temperatures?
An average high-temperature, in December, in Sag Harbor, is 7.2°C and the average low-temperature is 3.3°C.
What is the average humidity in December?
In Sag Harbor, the average relative humidity in December is 74%.
What is the wettest month?
December is the month with the most rainfall. Rain falls for 12.8 days and accumulates 97mm of precipitation.
How much does it rain in December?
In Sag Harbor, in December, during 12.8 rainfall days, 97mm of precipitation is typically accumulated.
How many days does it snow in December?
In Sag Harbor, in December, snow falls for 2.3 days, with typically accumulated 23mm of snow.
How cold is the water in December?
In December, the average ocean temperature is 9.9°C. At temperatures below 10°C, swimming in a suitably protected swimsuit is feasible; otherwise, cold shock and loss of breathing control are imminent. Even a short swim, without thermal protection, at temperatures around 13°C is not comfortable.
What is the month with the shortest days?
The month with the shortest days in Sag Harbor, New York, is December, with an average of 9h and 18min of daylight.
What is the average length of the day in December?
In December, the average day length is 9h and 17min.
When is the sunrise / sunset in December?
On the first day of December, sunrise is at 6:55 am and sunset at 4:21 pm. On the last day of the month, sunrise is at 7:13 am and sunset at 4:31 pm EST.
What is the month with the least sunshine?
December has the least sunshine of the year, with an average of 4.6h of sunshine.
How many hours of sunshine does Sag Harbor have in December?
The average sunshine duration in December is 4.6h.
When is the lowest UV index?
January through March and December, with an average maximum UV index of 2, are months with the lowest UV index.
How high is the UV index in December?
In December, the average daily maximum UV index is 2. A UV Index estimate of 2, and below, represents a low health risk from unprotected exposure to UV radiation.
Average high temperature
Average low temperature
Average wind speed
Average max. wind speed
Average wind speed gusts
Average humidity
Average rainfall
Average rainfall days
Average snowfall
Average snowfall days
Average sea temperature
Average daylight
Average sunshine
Average sunshine days
Average UV index
Average cloud cover
Average visibility
Average temperature in December - Sag Harbor, NY
Average temperature in December
Sag Harbor, NY
  • Average high temperature in December: 7.2°C

The warmest month (with the highest average high temperature) is August (24.4°C).
The month with the lowest average high temperature is January (3.8°C).

  • Average low temperature in December: 3.3°C

The month with the highest average low temperature is August (21.8°C).
The coldest month (with the lowest average low temperature) is January (-0.4°C).

Average pressure in December - Sag Harbor, NY
Average pressure in December
Sag Harbor, NY
  • Average pressure in December: 1017.6mbar

The month with the highest atmospheric pressure is November (1018.7mbar).
The month with the lowest atmospheric pressure is June (1013.7mbar).

Average wind speed in December - Sag Harbor, NY
Average wind speed in December
Sag Harbor, NY
  • Average wind speed in December: 25.2km/h

The windiest month (with the highest average wind speed) is January (25.7km/h).
The calmest month (with the lowest average wind speed) is July (16.8km/h).

Average humidity in December - Sag Harbor, NY
Average humidity in December
Sag Harbor, NY
  • Average humidity in December: 74%

The months with the highest relative humidity are May and June (81%).
The month with the lowest relative humidity is November (72%).

Average rainfall in December - Sag Harbor, NY
Average rainfall in December
Sag Harbor, NY
  • Average rainfall in December: 97mm

The wettest month (with the highest rainfall) is December (97mm).
The driest month (with the least rainfall) is September (55mm).

Average rainfall days in December - Sag Harbor, NY
Average rainfall days in December
Sag Harbor, NY
  • Average rainfall days in December: 12.8 days

The month with the highest number of rainy days is May (15.3 days).
The month with the least rainy days is January (9.1 days).

Average snowfall in December - Sag Harbor, NY
Average snowfall in December
Sag Harbor, NY
  • Average snowfall in December: 23mm

The month with the highest snowfall is March (60mm).
The months with the least snowfall are April, May, June, July, August, September and October (0mm).

Average snowfall days in December - Sag Harbor, NY
Average snowfall days in December
Sag Harbor, NY
  • Average snowfall days in December: 2.3 days

The month with the highest number of snowfall days is January (4.2 days).
The months with the least snowfall days are May, June, July, August, September and October (0 days).

Average sea temperature in December - Sag Harbor, NY
Average sea temperature in December
Sag Harbor, NY
  • Average sea temperature in December: 9.9°C

The best month for swimming (with the highest average sea temperature) is August (22.9°C).
The coldest month (with the lowest average sea temperature) is February (4.3°C).

Average daylight in December / Average sunshine in December - Sag Harbor, NY
Average daylight in December /
Average sunshine in December
Sag Harbor, 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 4min

The months with the most sunshine are July and August (Average sunshine: 10h and 36min).
The month with the least sunshine is December (Average sunshine: 4h and 36min).

Average sunshine days in December - Sag Harbor, NY
Average sunshine days in December
Sag Harbor, NY
  • Average sunshine days in December: 13.7 days

The month with the most sunshine days is November (16.8 days).
The month with the least sunshine days is February (12.8 days).

Average UV index in December - Sag Harbor, NY
Average UV index in December
Sag Harbor, 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 and December (UV index 2).

Average cloud cover in December - Sag Harbor, NY
Average cloud cover in December
Sag Harbor, NY
  • Average cloud cover in December: 52

The month with the most cloud cover is December (Cloud cover 52).
The month with the least cloud cover is August (Cloud cover 27).

Average visibility in December - Sag Harbor, NY
Average visibility in December
Sag Harbor, NY
  • Average visibility in December: 9km

The months with the highest visibility are June, July, August, September, October and November (10km).
The months with the lowest visibility are January, February, March, April, May and December (9km).

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