December weather forecastLocust Valley, NY

December

Weather in December

December, the first month of the winter in Locust Valley, is also a wintry month, with an average temperature fluctuating between 42.4°F (5.8°C) and 34.7°F (1.5°C).

Temperature

Locust Valley's December weather features a light decline in high-temperatures, reducing from a fresh 51.1°F (10.6°C) in November to a cold 42.4°F (5.8°C). Consistently, Locust Valley reports average nighttime temperatures of 34.7°F (1.5°C) during December, a marginal step down from its daytime highs.

Humidity

The months with the highest humidity in Locust Valley are February, May and December, with an average relative humidity of 75%.

Rainfall

December is the month with the most rainfall in Locust Valley. Rain falls for 12.9 days and accumulates 4.06" (103mm) of precipitation.

Snowfall

Months with snowfall in Locust Valley are January through April, November and December. In Locust Valley, in December, snow falls for 3.5 days, with typically accumulated 1.54" (39mm) of snow. Throughout the year, there are 22.2 snowfall days, and 7.24" (184mm) of snow is accumulated.

Daylight

December has the shortest days of the year in Locust Valley, with an average of 9h and 18min of daylight.
On the first day of December in Locust Valley, sunrise is at 7:00 am and sunset at 4:27 pm. On the last day of the month, sunrise is at 7:18 am and sunset at 4:36 pm EST.

Sunshine

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. A UV Index of 2, and less, symbolizes a low health risk from unsafe exposure to UV radiation for the ordinary person.
Note: In December, a daily maximum UV index of 2 leads to the following instructions:
Children, infants, and individuals with sensitive skin should be constantly protected from extended sun exposure. Direct Sun exposure should be minimized especially during midday when radiation is most intense. Tightly woven clothing, when worn loosely, shields effectively against the Sun. Be advised! The UV radiation from the Sun can be almost doubled due to the reflective properties of snow.

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

Frequently asked questions

In Locust Valley, in December, the average high-temperature is 42.4°F (5.8°C), and the average low-temperature is 34.7°F (1.5°C). The average heat index (a.k.a. 'feels like', 'apparent temperature'), which takes the relative humidity and factors it into the air temperature reading, in July is appraised at 86°F (30°C).

February, May and December, with an average relative humidity of 75%, are most humid months in Locust Valley.

In December, the average relative humidity is 75%.

The month with the most rainfall in Locust Valley is December, when the rain falls for 12.9 days and typically aggregates up to 4.06" (103mm) of precipitation.

In Locust Valley, in December, during 12.9 rainfall days, 4.06" (103mm) of precipitation is typically accumulated.

In December, it is snowing for 3.5 days. Throughout December, 1.54" (39mm) of snow is accumulated.

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

The average day length in December in Locust Valley, New York, is 9h and 18min.

In December, on the first day of the month, sunrise is at 7:00 am and sunset at 4:27 pm. On the last day of the month, sunrise is at 7:18 am and sunset at 4:36 pm EST.

In Locust Valley, the average sunshine duration in December is 4.9h.

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

In Locust Valley, the average daily maximum UV index in December is 2. A UV Index of 2, and less, symbolizes 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

51.1°F

42.4°F

36.5°F

Average low temperature

Average pressure

Average wind speed

Average max. wind speed

11.2mph

11.6mph

11.9mph

Average wind speed gusts

Average humidity

Average rainfall

Average rainfall days

Average snowfall

Average snowfall days

Average daylight

Average sunshine

Average sunshine days

15.5

17.3

Average UV index

Average cloud cover

Average visibility

Average temperature in December
Locust Valley, NY

Average high temperature in December: 42.4°F

The warmest month (with the highest average high temperature) is July (81.5°F).
The month with the lowest average high temperature is January (36.5°F).

Average low temperature in December: 34.7°F

The months with the highest average low temperature are July and August (70.3°F).
The coldest month (with the lowest average low temperature) is January (27.3°F).

Average pressure in December
Locust Valley, 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
Locust Valley, NY

Average wind speed in December: 10.8mph

The windiest month (with the highest average wind speed) is January (11.2mph).
The calmest month (with the lowest average wind speed) is July (7.3mph).

Average humidity in December
Locust Valley, NY

Average humidity in December: 75%

The months with the highest relative humidity are February, May and December (75%).
The months with the lowest relative humidity are August and November (71%).

Average rainfall in December
Locust Valley, NY

Average rainfall in December: 4.06"

The wettest month (with the highest rainfall) is December (4.06").
The driest month (with the least rainfall) is September (2.4").

Average rainfall days in December
Locust Valley, NY

Average rainfall days in December: 12.9 days

The month with the highest number of rainy days is July (17.9 days).
The month with the least rainy days is January (9.3 days).

Average snowfall in December
Locust Valley, NY

Average snowfall in December: 1.54"

The month with the highest snowfall is March (2.01").
The months with the least snowfall are May, June, July, August, September and October (0").

Average snowfall days in December
Locust Valley, NY

Average snowfall days in December: 3.5 days

The month with the highest number of snowfall days is January (6.8 days).
The months with the least snowfall days are June, July, August, September and October (0 days).

Average daylight in December /
Average sunshine in December
Locust Valley, 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 54min

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
Locust Valley, NY

Average sunshine days in December: 15.5 days

The month with the most sunshine days is November (18 days).
The month with the least sunshine days is July (10.6 days).

Average UV index in December
Locust Valley, 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
Locust Valley, NY

Average cloud cover in December: 47

The months with the most cloud cover are February and December (Cloud cover 47).
The months with the least cloud cover are July and August (Cloud cover 29).

Average visibility in December
Locust Valley, 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).