Contents
- Weather in December
- Frequently asked questions
- Average temperature in December
- Average pressure in December
- Average wind speed in December
- Average humidity in December
- Average rainfall in December
- Average rainfall days in December
- Average snowfall in December
- Average snowfall days in December
- Average daylight in December
- Average sunshine in December
- Average sunshine days in December
- Average UV index in December
- Average cloud cover in December
- Average visibility in December
Weather in December
Temperature
December brings a slight decrease in the average high-temperature, shifting from a cool 52.3°F (11.3°C) in November to a frosty 43.7°F (6.5°C). An average low-temperature of 32.4°F (0.2°C) is noted during the nights in December.Humidity
In December, the average relative humidity is 77%.Rainfall
In December, the rain falls for 10.9 days. Throughout December, 3.19" (81mm) of precipitation is accumulated. Throughout the year, in Greenbrook, there are 154.4 rainfall days, and 31.38" (797mm) of precipitation is accumulated.Snowfall
Months with snowfall are January through May, November and December. In Greenbrook, during December, snow falls for 2.8 days and regularly aggregates up to 1.22" (31mm) of snow. Throughout the year, there are 15.9 snowfall days, and 8.5" (216mm) of snow is accumulated.Daylight
December has the shortest days of the year in Greenbrook, Pennsylvania, with an average of 9h and 24min of daylight.On the first day of December, sunrise is at 7:03 am and sunset at 4:34 pm. On the last day of the month, sunrise is at 7:21 am and sunset at 4:43 pm EST.
Sunshine
In December, the average sunshine is 5h.UV index
The months with the lowest UV index are January, February, November and December, with an average maximum UV index of 2. A UV Index value of 2, and less, symbolizes a minimal health vulnerability from exposure to the Sun's UV radiation for ordinary individuals.Note: In December, the maximum UV index of 2 suggests these 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. Protect yourself from the midday Sun's peak UV radiation by minimizing exposure. Clothes that are both tight-knit and comfortably loose are prime choices for sun protection. Caution! The reflection of snow can nearly double the intensity of the Sun's UV radiation.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Is it cold in Greenbrook during December?
What is the average humidity in December in Greenbrook?
How many days does it rain in December in Greenbrook?
How much does it snow in Greenbrook in December?
What is the month with the shortest days in Greenbrook?
What is the average length of the day in December in Greenbrook?
When is the sunrise / sunset in December in Greenbrook?
How long on average sun shines in December in Greenbrook?
What are the months with the lowest UV index in Greenbrook?
How high is the UV index in December in Greenbrook?
Average temperature in December
Greenbrook, PA
- Average high temperature in December: 43.7°F
The warmest month (with the highest average high temperature) is July (85.5°F).
The month with the lowest average high temperature is January (37°F).
- Average low temperature in December: 32.4°F
The month with the highest average low temperature is July (68°F).
The coldest month (with the lowest average low temperature) is January (25.2°F).
Average pressure in December
Greenbrook, PA
- Average pressure in December: 30.09"Hg
The month with the highest atmospheric pressure is November (30.11"Hg).
The month with the lowest atmospheric pressure is June (29.93"Hg).
Average wind speed in December
Greenbrook, PA
- Average wind speed in December: 7.6mph
The windiest month (with the highest average wind speed) is March (8.6mph).
The calmest month (with the lowest average wind speed) is August (5.4mph).
Average humidity in December
Greenbrook, PA
- Average humidity in December: 77%
The months with the highest relative humidity are February and October (78%).
The month with the lowest relative humidity is April (72%).
Average rainfall in December
Greenbrook, PA
- Average rainfall in December: 3.19"
The wettest month (with the highest rainfall) is July (3.66").
The driest month (with the least rainfall) is January (1.89").
Average rainfall days in December
Greenbrook, PA
- Average rainfall days in December: 10.9 days
The month with the highest number of rainy days is July (18.8 days).
The month with the least rainy days is January (8 days).
Average snowfall in December
Greenbrook, PA
- Average snowfall in December: 1.22"
The month with the highest snowfall is March (2.99").
The months with the least snowfall are June, July, August, September and October (0").
Average snowfall days in December
Greenbrook, PA
- Average snowfall days in December: 2.8 days
The month with the highest number of snowfall days is January (4.8 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
Greenbrook, 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 24min).
- Average sunshine in December: 5h and 0min
The month with the most sunshine is July (Average sunshine: 10h and 36min).
The month with the least sunshine is February (Average sunshine: 4h and 48min).
Average sunshine days in December
Greenbrook, PA
- Average sunshine days in December: 18.1 days
The month with the most sunshine days is November (20.6 days).
The month with the least sunshine days is July (9.9 days).
Average UV index in December
Greenbrook, PA
- Average UV index in December: 2
The months with the highest UV index are May, June, July and August (UV index 6).
The months with the lowest UV index are January, February, November and December (UV index 2).
Average cloud cover in December
Greenbrook, PA
- Average cloud cover in December: 46
The months with the most cloud cover are February and March (Cloud cover 47).
The month with the least cloud cover is July (Cloud cover 32).
Average visibility in December
Greenbrook, PA
- Average visibility in December: 6mi
The months with the highest visibility are January, February, March, April, June, July, August, September, October, November and December (6mi).
The month with the lowest visibility is May (5mi).
Greenbrook, Pennsylvania, USA
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