December weather forecastGlen Rock, NJ
December
Weather in December
The first month of the winter, December, is also an icy month in Glen Rock, New Jersey, with an average temperature varying between 30.9°F (-0.6°C) and 41.2°F (5.1°C).Temperature
In Glen Rock, the beginning of December is marked by a lowered average high-temperature, shifting from November's fresh 50.9°F (10.5°C) to an icy 41.2°F (5.1°C). December brings Glen Rock a consistent average low-temperature of 30.9°F (-0.6°C).Humidity
February and December, with an average relative humidity of 78%, are the most humid months.Rainfall
The wettest months are July and December, with an average 3.07" (78mm) of rainfall.Snowfall
Months with snowfall are January through May, October through December. In Glen Rock, in December, snow falls for 4 days, with typically accumulated 1.54" (39mm) of snow. In Glen Rock, during the entire year, snow falls for 24.9 days and aggregates up to 10.04" (255mm) of snow.Daylight
December has the shortest days of the year, with an average of 9h and 18min of daylight.On the first day of December, sunrise is at 7:02 am and sunset at 4:29 pm. On the last day of the month, sunrise is at 7:21 am and sunset at 4:38 pm EST.
Sunshine
In December, the average sunshine is 4.8h.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 of 2, and less, symbolizes a low health risk from unsafe exposure to UV radiation for the average person.Note: An average UV index of 2 in December transforms into this advice:
Many can withstand an hour in the sun without burning, yet children must always have protection against sunlight. Direct Sun exposure should be minimized especially during midday when radiation is most intense. Employ a hat with a wide brim for robust protection, cutting UV exposure by half. Alert! The snow's reflection can amplify the UV radiation of the Sun nearly twice.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in December
Glen Rock, NJ
- Average high temperature in December: 41.2°F
The warmest month (with the highest average high temperature) is July (84.4°F).
The month with the lowest average high temperature is January (35.2°F).
- Average low temperature in December: 30.9°F
The month with the highest average low temperature is July (66.7°F).
The coldest month (with the lowest average low temperature) is January (23.4°F).
Average pressure in December
Glen Rock, NJ
- Average pressure in December: 30.07"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
Glen Rock, NJ
- Average wind speed in December: 7.8mph
The windiest month (with the highest average wind speed) is March (8.4mph).
The calmest months (with the lowest average wind speed) are July and August (5.5mph).
Average humidity in December
Glen Rock, NJ
- Average humidity in December: 78%
The months with the highest relative humidity are February and December (78%).
The months with the lowest relative humidity are April, July and August (72%).
Average rainfall in December
Glen Rock, NJ
- Average rainfall in December: 3.07"
The wettest months (with the highest rainfall) are July and December (3.07").
The driest month (with the least rainfall) is September (1.73").
Average rainfall days in December
Glen Rock, NJ
- Average rainfall days in December: 11.2 days
The month with the highest number of rainy days is June (17 days).
The month with the least rainy days is January (8.9 days).
Average snowfall in December
Glen Rock, NJ
- Average snowfall in December: 1.54"
The month with the highest snowfall is February (3.23").
The months with the least snowfall are June, July, August and September (0").
Average snowfall days in December
Glen Rock, NJ
- Average snowfall days in December: 4 days
The month with the highest number of snowfall days is February (7.2 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, NJ
- 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 48min
The month with the most sunshine is July (Average sunshine: 10h and 24min).
The month with the least sunshine is February (Average sunshine: 4h and 36min).
Average sunshine days in December
Glen Rock, NJ
- Average sunshine days in December: 15.7 days
The month with the most sunshine days is November (18.8 days).
The month with the least sunshine days is June (10.5 days).
Average UV index in December
Glen Rock, NJ
- 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
Glen Rock, NJ
- Average cloud cover in December: 48
The month with the most cloud cover is March (Cloud cover 49).
The month with the least cloud cover is August (Cloud cover 33).
Average visibility in December
Glen Rock, NJ
- 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).
