December weather forecastGreenport, NY

December

Weather in December

December, the first month of the winter in Greenport, is still a chilly month, with an average temperature fluctuating between 37.9°F (3.3°C) and 45°F (7.2°C).

Temperature

In Greenport, the average high-temperature in December slightly decreases from a cool 52.7°F (11.5°C) in November to a frosty 45°F (7.2°C). Greenport's average temperature throughout the nights in December exhibits a minor decrease from daytime highs, stabilizing at a cold 37.9°F (3.3°C).

Humidity

In Greenport, the average relative humidity in December is 74%.

Rainfall

December is the month with the most rainfall. Rain falls for 12.8 days and accumulates 3.82" (97mm) of precipitation.

Snowfall

January through March, November and December are months with snowfall in Greenport. In Greenport, in December, snow falls for 2.3 days, with typically accumulated 0.91" (23mm) of snow. Throughout the year, in Greenport, New York, there are 13.9 snowfall days, and 6.61" (168mm) of snow is accumulated.

Ocean temperature

In December, the average ocean temperature in Greenport is 48.9°F (9.4°C).
Note: Diving into 48.9°F (9.4°C) is practical below 50°F (10°C), given you're wearing protective swim gear; without it, expect a quick onset of cold shock and a struggle to breathe. Merely touching waters at 55.4°F (13°C) feels ice-cold.

Daylight

The month with the shortest days is December, with an average of 9h and 18min of daylight.
On the first day of December in Greenport, sunrise is at 6:55 am and sunset at 4:21 pm. On the last day of the month, sunrise is at 7:14 am and sunset at 4:30 pm EST.

Sunshine

December has the least sunshine of the year, with an average of 4.6h of sunshine.

UV index

January through March and December, with an average maximum UV index of 2, are months with the lowest UV index. A UV Index value of 2, and less, symbolizes a minimal health hazard from unprotected exposure to Sun's UV rays for the average person.
Note: In December, the maximum UV index of 2 transforms into these recommendations:
Prolonged exposure to sunlight rarely troubles the majority, but constant protection is vital for babies, children, and fair-skinned people. The Sun's most intense and consequently most harmful UV radiation during midday hours should be decreased by minimizing exposure and seeking shade. Combat UV radiation's detrimental effects with sun-safe clothing and UV-blocking eyewear. On your guard! Snow's reflection can almost double the intensity of the Sun's UV radiation.

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

Frequently asked questions

In December, the average high-temperature and low-temperature in Greenport, New York, are 45°F (7.2°C) and 37.9°F (3.3°C) respectively.

In Greenport, New York, the average relative humidity in December is 74%.

The month with the most rainfall in Greenport is December, when the rain falls for 12.8 days and typically aggregates up to 3.82" (97mm) of precipitation.

In Greenport, New York, in December, it is raining for 12.8 days, with typically 3.82" (97mm) of accumulated precipitation.

In December, in Greenport, New York, it is snowing for 2.3 days. Throughout December, 0.91" (23mm) of snow is accumulated.

In December, the average ocean temperature in Greenport, New York, is 48.9°F (9.4°C). At temperatures below 50°F (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 55.4°F (13°C) is not comfortable.

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

In December, the average day length in Greenport is 9h and 16min.

In December, on the first day of the month, sunrise is at 6:55 am and sunset at 4:21 pm. On the last day of the month, in Greenport, New York, sunrise is at 7:14 am and sunset at 4:30 pm EST.

The month with the least sunshine in Greenport, New York, is December, with an average of 4.6h of sunshine.

In Greenport, New York, the average sunshine duration in December is 4.6h.

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

In Greenport, the average daily maximum UV index in December is 2. A UV Index estimate of 2, and below, represents a minimal hazard to health from unsafe exposure to Sun's UV rays.

Today

Tomorrow

Long-term

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

Nov

December

Jan

Average high temperature

52.7°F

45°F

38.8°F

Average low temperature

Average pressure

Average wind speed

Average max. wind speed

16.3mph

16.7mph

16.8mph

Average wind speed gusts

Average humidity

Average rainfall

Average rainfall days

Average snowfall

Average snowfall days

0.2

2.3

4.2

Average sea temperature

Average daylight

Average sunshine

Average sunshine days

16.8

13.7

15.3

Average UV index

Average cloud cover

Average visibility

Average temperature in December
Greenport, NY

Average high temperature in December: 45°F

The warmest month (with the highest average high temperature) is August (75.9°F).
The month with the lowest average high temperature is January (38.8°F).

Average low temperature in December: 37.9°F

The month with the highest average low temperature is August (71.2°F).
The coldest month (with the lowest average low temperature) is January (31.3°F).

Average pressure in December
Greenport, NY

Average pressure in December: 30.05"Hg

The month with the highest atmospheric pressure is November (30.08"Hg).
The month with the lowest atmospheric pressure is June (29.93"Hg).

Average wind speed in December
Greenport, NY

Average wind speed in December: 15.7mph

The windiest month (with the highest average wind speed) is January (16mph).
The calmest month (with the lowest average wind speed) is July (10.4mph).

Average humidity in December
Greenport, 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
Greenport, NY

Average rainfall in December: 3.82"

The wettest month (with the highest rainfall) is December (3.82").
The driest month (with the least rainfall) is September (2.17").

Average rainfall days in December
Greenport, 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
Greenport, NY

Average snowfall in December: 0.91"

The month with the highest snowfall is March (2.36").
The months with the least snowfall are April, May, June, July, August, September and October (0").

Average snowfall days in December
Greenport, 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
Greenport, NY

Average sea temperature in December: 48.9°F

The best month for swimming (with the highest average sea temperature) is August (72.1°F).
The coldest month (with the lowest average sea temperature) is February (38.8°F).

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

Average daylight in December: 9h and 18min

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 36min

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
Greenport, 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
Greenport, 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
Greenport, 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
Greenport, 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).