December weather forecastGlen Rock, PA
December
Weather in December
The first month of the winter, December, is also a wintry month in Glen Rock, Pennsylvania, with an average temperature varying between 30.7°F (-0.7°C) and 42.3°F (5.7°C).Temperature
Glen Rock in December undergoes a slight reduction in the average high-temperature, shifting from November's fresh 51.1°F (10.6°C) to an icy 42.3°F (5.7°C). The mean low-temperature during December nights is a subzero cold 30.7°F (-0.7°C).Humidity
The average relative humidity in December is 79%.Rainfall
In December, the rain falls for 9.2 days. Throughout December, 1.73" (44mm) of precipitation is accumulated. Throughout the year, there are 145.3 rainfall days, and 24.88" (632mm) of precipitation is accumulated.Snowfall
Months with snowfall are January through May, October through December. In Glen Rock, during December, snow falls for 2.9 days and regularly aggregates up to 1.42" (36mm) of snow. Throughout the year, there are 19.2 snowfall days, and 10.59" (269mm) of snow is accumulated.Daylight
The month with the shortest days is December, with an average of 9h and 24min of daylight.On the first day of the month, sunrise is at 7:09 am and sunset at 4:42 pm. On the last day of December, sunrise is at 7:27 am and sunset at 4:52 pm EST.
Sunshine
In Glen Rock, the average sunshine in December is 5h.UV index
January, February, November and December, with an average maximum UV index of 2, are months with the lowest UV index. A UV Index reading of 2, and below, represents a minimal health vulnerability from unprotected exposure to Sun's UV rays for ordinary individuals.Note: In December, a daily maximum UV index of 2 leads to the following instructions:
Unlike children, who always need sun protection, most individuals can remain in the sun for up to an hour without getting burnt. UV radiation from the Sun is most dangerous during midday; take precautions and seek shade. Safeguard your eyes, ears, and face from sun rays with the aid of a wide-brim hat. Take heed! The reflection of snow can intensify the Sun's UV radiation nearly double.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in December
Glen Rock, PA
- Average high temperature in December: 42.3°F
The warmest month (with the highest average high temperature) is July (83.5°F).
The month with the lowest average high temperature is January (36.1°F).
- Average low temperature in December: 30.7°F
The month with the highest average low temperature is July (65.8°F).
The coldest month (with the lowest average low temperature) is January (23.5°F).
Average pressure in December
Glen Rock, 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 (29.94"Hg).
Average wind speed in December
Glen Rock, PA
- Average wind speed in December: 8.2mph
The windiest months (with the highest average wind speed) are February and March (8.9mph).
The calmest month (with the lowest average wind speed) is August (5.2mph).
Average humidity in December
Glen Rock, PA
- Average humidity in December: 79%
The month with the highest relative humidity is May (81%).
The months with the lowest relative humidity are January, March, April and November (76%).
Average rainfall in December
Glen Rock, PA
- Average rainfall in December: 1.73"
The wettest month (with the highest rainfall) is August (3.03").
The driest month (with the least rainfall) is February (1.38").
Average rainfall days in December
Glen Rock, PA
- Average rainfall days in December: 9.2 days
The month with the highest number of rainy days is May (16.8 days).
The month with the least rainy days is January (6.5 days).
Average snowfall in December
Glen Rock, PA
- Average snowfall in December: 1.42"
The month with the highest snowfall is March (3.43").
The months with the least snowfall are June, July, August and September (0").
Average snowfall days in December
Glen Rock, PA
- Average snowfall days in December: 2.9 days
The month with the highest number of snowfall days is January (5.5 days).
The months with the least snowfall days are June, July, August and September (0 days).
Average daylight in December /
Average sunshine in December
Glen Rock, PA
- Average daylight in December: 9h and 24min
The month with the longest days is June (Average daylight: 14h and 54min).
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 42min).
The month with the least sunshine is February (Average sunshine: 4h and 42min).
Average sunshine days in December
Glen Rock, PA
- Average sunshine days in December: 19 days
The month with the most sunshine days is November (20.1 days).
The month with the least sunshine days is May (11.1 days).
Average UV index in December
Glen Rock, PA
- 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, November and December (UV index 2).
Average cloud cover in December
Glen Rock, 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 30).
Average visibility in December
Glen Rock, PA
- Average visibility in December: 6mi
The months with the highest visibility are January, February, March, April, June, July, August, October, November and December (6mi).
The months with the lowest visibility are May and September (5mi).
