December weather forecast
Sayville, NY

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Weather in December

December, the first month of the winter in Sayville, is still a chilly month, with an average temperature fluctuating between 37.2°F (2.9°C) and 44.1°F (6.7°C).

Temperature

December signifies a gentle decline in Sayville's average high-temperature, easing from a cool 52.3°F (11.3°C) in November to a chilly 44.1°F (6.7°C). In Sayville, the December nights are characterized by an average low-temperature of 37.2°F (2.9°C), a minor dip from daytime readings.

Humidity

The average relative humidity in December is 74%.

Rainfall

The month with the most rainfall in Sayville is December, when the rain falls for 12.3 days and typically aggregates up to 3.74" (95mm) of precipitation.

Snowfall

January through March, May, October and December are months with snowfall in Sayville. December is the first month it typically snows in Sayville. Throughout December, in the average 2.4 snowfall days, it receives 1.22" (31mm) of snow. Throughout the year, in Sayville, there are 14.7 snowfall days, and 6.14" (156mm) of snow is accumulated.

Daylight

December has the shortest days of the year, with an average of 9h and 18min of daylight.
On the first day of December in Sayville, sunrise is at 6:57 am and sunset at 4:25 pm. On the last day of the month, sunrise is at 7:16 am and sunset at 4:35 pm EST.

Sunshine

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

UV index

January through March and December, with an average maximum UV index of 2, are months with the lowest UV index in Sayville. A UV Index reading of 2, and below, represents a minimal health hazard from unprotected exposure to Sun's UV rays for average individuals.
Note: The maximum daily UV index, 2 in December, converts into the following recommendations:
Extended sunlight exposure does not pose significant problems for most people, except for children, infants, and people with fair skin who always need shielding. UV radiation from the Sun is most dangerous during midday; take precautions and seek shade. On days when the sun blazes, arm yourself with sunglasses that block UVA and UVB radiation. Note this! The Sun's UV radiation can nearly be doubled by the reflection off snow.
Updated: Feb 13, 2024
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate

Frequently asked questions

How cold is it in Sayville in December?

The high-temperature during December is 44.1°F (6.7°C) and the low-temperature is 37.2°F (2.9°C).

What is the average humidity in December in Sayville?

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

What is the wettest month in Sayville?

December is the month with the most rainfall. Rain falls for 12.3 days and accumulates 3.74" (95mm) of precipitation.

How many days does it rain in December in Sayville?

In Sayville, New York, in December, it is raining for 12.3 days, with typically 3.74" (95mm) of accumulated precipitation.

When does it start to snow in Sayville?

December is the first month it typically snows in Sayville. Throughout December, in the average 2.4 snowfall days, it receives 1.22" (31mm) of snow.

What is the month with the shortest days in Sayville?

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

What is the average length of the day in December in Sayville?

In Sayville, the average day length in December is 9h and 19min.

When is the sunrise / sunset in December in Sayville?

In December, on the first day of the month, sunrise is at 6:57 am and sunset at 4:25 pm. On the last day of the month, in Sayville, sunrise is at 7:16 am and sunset at 4:35 pm EST.

How many hours of sunshine does Sayville have in December?

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

What are the months with the lowest UV index in Sayville?

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

How high is the UV index in December in Sayville?

In Sayville, New York, the average daily maximum UV index in December is 2. A UV Index value of 2, and less, symbolizes a minimal hazard to health from 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
Sayville, NY

Average temperature in December - Sayville, NY
  • Average high temperature in December: 44.1°F

The warmest month (with the highest average high temperature) is August (78.1°F).
The month with the lowest average high temperature is January (37.9°F).

  • Average low temperature in December: 37.2°F

The month with the highest average low temperature is August (71.8°F).
The coldest month (with the lowest average low temperature) is January (30.2°F).

Average pressure in December
Sayville, NY

Average pressure in December - Sayville, NY
  • Average pressure in December: 30.06"Hg

The month with the highest atmospheric pressure is November (30.09"Hg).
The month with the lowest atmospheric pressure is June (29.93"Hg).

Average wind speed in December
Sayville, NY

Average wind speed in December - Sayville, NY
  • Average wind speed in December: 13.4mph

The windiest month (with the highest average wind speed) is January (13.8mph).
The calmest months (with the lowest average wind speed) are July and August (9mph).

Average humidity in December
Sayville, NY

Average humidity in December - Sayville, NY
  • Average humidity in December: 74%

The months with the highest relative humidity are May and June (78%).
The month with the lowest relative humidity is November (71%).

Average rainfall in December
Sayville, NY

Average rainfall in December - Sayville, NY
  • Average rainfall in December: 3.74"

The wettest month (with the highest rainfall) is December (3.74").
The driest month (with the least rainfall) is January (2.17").

Average rainfall days in December
Sayville, NY

Average rainfall days in December - Sayville, NY
  • Average rainfall days in December: 12.3 days

The month with the highest number of rainy days is July (17.7 days).
The month with the least rainy days is January (8.3 days).

Average snowfall in December
Sayville, NY

Average snowfall in December - Sayville, NY
  • Average snowfall in December: 1.22"

The month with the highest snowfall is March (2.13").
The months with the least snowfall are April, June, July, August, September and November (0").

Average snowfall days in December
Sayville, NY

Average snowfall days in December - Sayville, NY
  • Average snowfall days in December: 2.4 days

The month with the highest number of snowfall days is February (4.6 days).
The months with the least snowfall days are June, July, August and September (0 days).

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

Average daylight in December / Average sunshine in December - Sayville, NY
  • Average daylight in December: 9h and 2min

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: 4h and 5min

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 48min).

Average sunshine days in December
Sayville, NY

Average sunshine days in December - Sayville, NY
  • Average sunshine days in December: 16.9 days

The month with the most sunshine days is November (18.8 days).
The month with the least sunshine days is July (11.3 days).

Average UV index in December
Sayville, NY

Average UV index in December - Sayville, 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
Sayville, NY

Average cloud cover in December - Sayville, NY
  • Average cloud cover in December: 48

The month with the most cloud cover is December (Cloud cover 48).
The month with the least cloud cover is August (Cloud cover 27).

Average visibility in December
Sayville, NY

Average visibility in December - Sayville, 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).

Sayville, New York, USA

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