December weather forecast
Brentwood, PA

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Weather in December

The first month of the winter, December, is also an icy month in Brentwood, Pennsylvania, with an average temperature varying between 28.2°F (-2.1°C) and 39.7°F (4.3°C).

Temperature

The transition into December is accompanied by a temperature decrease, with the average high-temperature shifting from a chilly 49.3°F (9.6°C) in November to a cold 39.7°F (4.3°C). December nights observe an average temperature dip to a freezing cold 28.2°F (-2.1°C).

Humidity

In Brentwood, the average relative humidity in December is 83%.

Rainfall

In Brentwood, during December, the rain falls for 10.7 days and regularly aggregates up to 2.09" (53mm) of precipitation. Throughout the year, there are 164 rainfall days, and 26.89" (683mm) of precipitation is accumulated.

Snowfall

January through April, October through December are months with snowfall. In Brentwood, during December, snow falls for 11.8 days and regularly aggregates up to 2.64" (67mm) of snow. In Brentwood, during the entire year, snow falls for 53.3 days and aggregates up to 13.27" (337mm) of snow.

Daylight

With an average of 9h and 18min of daylight, December has the shortest days of the year.
On the first day of the month, sunrise is at 7:24 am and sunset at 4:54 pm. On the last day of December, sunrise is at 7:42 am and sunset at 5:03 pm EST.

Sunshine

The average sunshine in December is 3.3h.

UV index

December is the month with the lowest UV index, with an average maximum UV index of 1. A UV Index of 2, and less, symbolizes a minimal health vulnerability from unprotected exposure to Sun's UV rays for ordinary individuals.
Note: A maximum high UV index of 1 in December translates into the following recommendations:
Extended exposure to the sun should always be avoided by children, infants, and those with sensitive skin. Solar radiation peaks around mid-day, so it's wise to limit exposure to the Sun at this time. For a sun-safe wardrobe, go for clothes that are tightly woven and generously sized. Heads up! The UV radiation from the Sun can almost be doubled by snow reflection.
Updated: Aug 14, 2024
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate

Frequently asked questions

Is it cold during December?

In Brentwood, in December, the average high-temperature is 39.7°F (4.3°C), and the average low-temperature is 28.2°F (-2.1°C). The average heat index (a.k.a. 'felt air temperature', 'real feel'), which combines relative humidity and air temperature, in August is appraised at 87.8°F (31°C).

What is the average humidity in December?

In December, the average relative humidity is 83%.

How many days does it rain in December?

In December, the rain falls for 10.7 days. Throughout December, 2.09" (53mm) of precipitation is accumulated.

How many days does it snow in December in Brentwood?

In Brentwood, in December, snow falls for 11.8 days, with typically accumulated 2.64" (67mm) of snow.

What is the month with the shortest days?

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

How many hours of daylight does Brentwood have in December?

In December, the average day length in Brentwood is 9h and 21min.

When are sunrise and sunset in December?

In December, on the first day of the month, sunrise is at 7:24 am and sunset at 4:54 pm. On the last day of the month, sunrise is at 7:42 am and sunset at 5:03 pm EST.

How long on average sun shines in December?

In December, the average sunshine duration is 3.3h.

When is the lowest UV index in Brentwood?

The month with the lowest UV index is December, with an average maximum UV index of 1.

What is the UV index reading in December?

In December, the average daily maximum UV index is 1. A UV Index value of 2, and less, symbolizes a minimal health vulnerability 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
Brentwood, PA

Average temperature in December - Brentwood, PA
  • Average high temperature in December: 39.7°F

The warmest month (with the highest average high temperature) is July (83.8°F).
The month with the lowest average high temperature is January (33.4°F).

  • Average low temperature in December: 28.2°F

The month with the highest average low temperature is July (63°F).
The coldest month (with the lowest average low temperature) is January (20.8°F).

Average pressure in December
Brentwood, PA

Average pressure in December - Brentwood, PA
  • Average pressure in December: 30.11"Hg

The month with the highest atmospheric pressure is November (30.13"Hg).
The month with the lowest atmospheric pressure is June (29.95"Hg).

Average wind speed in December
Brentwood, PA

Average wind speed in December - Brentwood, PA
  • Average wind speed in December: 7.3mph

The windiest month (with the highest average wind speed) is January (7.9mph).
The calmest month (with the lowest average wind speed) is August (4.7mph).

Average humidity in December
Brentwood, PA

Average humidity in December - Brentwood, PA
  • Average humidity in December: 83%

The months with the highest relative humidity are January and February (84%).
The month with the lowest relative humidity is August (73%).

Average rainfall in December
Brentwood, PA

Average rainfall in December - Brentwood, PA
  • Average rainfall in December: 2.09"

The wettest month (with the highest rainfall) is May (3.07").
The driest month (with the least rainfall) is November (1.61").

Average rainfall days in December
Brentwood, PA

Average rainfall days in December - Brentwood, PA
  • Average rainfall days in December: 10.7 days

The month with the highest number of rainy days is May (18.4 days).
The month with the least rainy days is January (8.5 days).

Average snowfall in December
Brentwood, PA

Average snowfall in December - Brentwood, PA
  • Average snowfall in December: 2.64"

The month with the highest snowfall is January (3.46").
The months with the least snowfall are May, June, July, August and September (0").

Average snowfall days in December
Brentwood, PA

Average snowfall days in December - Brentwood, PA
  • Average snowfall days in December: 11.8 days

The month with the highest number of snowfall days is January (16.3 days).
The months with the least snowfall days are May, June, July, August and September (0 days).

Average daylight in December /
Average sunshine in December
Brentwood, PA

Average daylight in December / Average sunshine in December - Brentwood, PA
  • 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: 3h and 2min

The month with the most sunshine is August (Average sunshine: 10h and 6min).
The month with the least sunshine is January (Average sunshine: 2h and 54min).

Average sunshine days in December
Brentwood, PA

Average sunshine days in December - Brentwood, PA
  • Average sunshine days in December: 11 days

The month with the most sunshine days is November (16.4 days).
The month with the least sunshine days is February (9.5 days).

Average UV index in December
Brentwood, PA

Average UV index in December - Brentwood, PA
  • Average UV index in December: 1

The months with the highest UV index are June and July (UV index 6).
The month with the lowest UV index is December (UV index 1).

Average cloud cover in December
Brentwood, PA

Average cloud cover in December - Brentwood, PA
  • Average cloud cover in December: 66

The month with the most cloud cover is January (Cloud cover 69).
The month with the least cloud cover is August (Cloud cover 34).

Average visibility in December
Brentwood, PA

Average visibility in December - Brentwood, PA
  • Average visibility in December: 5mi

The months with the highest visibility are April, June, July, August and November (6mi).
The months with the lowest visibility are January, February, March, May, September, October and December (5mi).

Brentwood, Pennsylvania, USA

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