December weather forecastUpper Brookville, NY

December

Weather in December

The first month of the winter, December, is also an icy month in Upper Brookville, New York, with an average temperature fluctuating between 42.4°F (5.8°C) and 34.7°F (1.5°C).

Temperature

The arrival of December correlates with a minor temperature reduction, down from November's fresh 51.1°F (10.6°C) to an icy 42.4°F (5.8°C). December nights cool to an average low-temperature of 34.7°F (1.5°C), a marginal decrease from its daytime equivalent.

Humidity

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

Rainfall

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

Snowfall

Months with snowfall are January through April, November and December. In December, it is snowing for 3.5 days. Throughout December, 1.54" (39mm) of snow is accumulated. In Upper Brookville, during the entire year, snow falls for 22.2 days and aggregates up to 7.24" (184mm) of snow.

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 Upper Brookville, sunrise is at 6:59 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

In December, the average sunshine is 4.9h.

UV index

The months with the lowest UV index are January through March, November and December, with an average maximum UV index of 2. A UV Index reading of 2, and below, represents a minimal health vulnerability from exposure to the Sun's UV rays for the average person.
Note: In December, the average maximum UV index of 2 translates into the following recommendations:
Children, infants, and individuals with sensitive skin should be constantly protected from extended sun exposure. The Sun is most powerful around mid-day, so it's a good practice to reduce direct exposure. Always opt for UVA and UVB-resistant sunglasses on radiant days. Be aware! The intensity of the Sun's UV radiation can be amplified nearly twice due to snow reflection.
Updated: Jul 28, 2024
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate

Frequently asked questions

The high-temperature during December is 42.4°F (5.8°C) and the low-temperature is 34.7°F (1.5°C). In July, the average heat index (a.k.a. 'feels like', 'real feel'), which factors the actual air temperature with the relative humidity, is calculated to be 86°F (30°C).

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

The average relative humidity in December is 75%.

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

In Upper Brookville, during December, the rain falls for 12.9 days and regularly aggregates up to 4.06" (103mm) of precipitation.

In Upper Brookville, in December, snow falls for 3.5 days, with typically accumulated 1.54" (39mm) of snow.

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

The average day length in December in Upper Brookville is 9h and 18min.

On the first day of December, sunrise is at 6:59 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 Upper Brookville, the average sunshine duration in December is 4.9h.

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

The average daily maximum UV index in December is 2. A UV Index reading of 2, and below, represents a low health threat from exposure to Sun's UV rays.
Average high temperature
Average low temperature
Average pressure
Average wind speed
Average max. wind speed
Average wind speed gusts
Average humidity
Average rainfall
Average rainfall days
Average snowfall
Average snowfall days
Average daylight
Average sunshine
Average sunshine days
Average UV index
Average cloud cover
Average visibility

Average temperature in December
Upper Brookville, 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
Upper Brookville, 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
Upper Brookville, 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
Upper Brookville, 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
Upper Brookville, 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
Upper Brookville, 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
Upper Brookville, 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
Upper Brookville, 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
Upper Brookville, 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
Upper Brookville, 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
Upper Brookville, 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
Upper Brookville, 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
Upper Brookville, 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).