December weather forecastRockleigh, NJ
December
Weather in December
The first month of the winter, December, is also an icy month in Rockleigh, New Jersey, with an average temperature ranging between min 30.9°F (-0.6°C) and max 41.7°F (5.4°C).Temperature
Transition into December marks a drop in the average high-temperature, moving from a cool 50.9°F (10.5°C) in November to a wintry 41.7°F (5.4°C). Rockleigh experiences a mean temperature of 30.9°F (-0.6°C) during December nights.Humidity
In Rockleigh, the average relative humidity in December is 76%.Rainfall
The month with the most rainfall is December, when the rain falls for 10.7 days and typically aggregates up to 3.46" (88mm) of precipitation.Snowfall
Months with snowfall in Rockleigh are January through April, November and December. In Rockleigh, during December, snow falls for 4.6 days and regularly aggregates up to 1.93" (49mm) of snow. In Rockleigh, during the entire year, snow falls for 25.5 days and aggregates up to 10.55" (268mm) 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 the month, sunrise is at 7:01 am and sunset at 4:28 pm. On the last day of December, sunrise is at 7:20 am and sunset at 4:37 pm EST.
Sunshine
In December, the average sunshine is 4.7h.UV index
The months with the lowest UV index in Rockleigh 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 hazard from exposure to the Sun's UV radiation for ordinary individuals.Note: In December, a daily UV index of 2 turns into the following recommendations:
While most people are not greatly affected by extended sun exposure, those with fair skin, babies, and children must always have protection. Avoiding the Sun during its peak radiation time around midday is a healthy practice. To best shield against UV radiation, choose sun-safe garments and dependable sunglasses. On your guard! Snow's reflection can almost double the intensity of the Sun's UV radiation.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in December
Rockleigh, NJ
- Average high temperature in December: 41.7°F
The warmest month (with the highest average high temperature) is July (84.9°F).
The month with the lowest average high temperature is January (35.4°F).
- Average low temperature in December: 30.9°F
The month with the highest average low temperature is July (68°F).
The coldest month (with the lowest average low temperature) is January (24.1°F).
Average pressure in December
Rockleigh, NJ
- 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
Rockleigh, NJ
- Average wind speed in December: 8mph
The windiest months (with the highest average wind speed) are January and March (8.5mph).
The calmest months (with the lowest average wind speed) are July and August (5.8mph).
Average humidity in December
Rockleigh, NJ
- Average humidity in December: 76%
The month with the highest relative humidity is February (77%).
The month with the lowest relative humidity is August (68%).
Average rainfall in December
Rockleigh, NJ
- Average rainfall in December: 3.46"
The wettest month (with the highest rainfall) is December (3.46").
The driest month (with the least rainfall) is September (1.73").
Average rainfall days in December
Rockleigh, NJ
- Average rainfall days in December: 10.7 days
The month with the highest number of rainy days is May (16.8 days).
The month with the least rainy days is January (8.2 days).
Average snowfall in December
Rockleigh, NJ
- Average snowfall in December: 1.93"
The month with the highest snowfall is March (3.07").
The months with the least snowfall are May, June, July, August, September and October (0").
Average snowfall days in December
Rockleigh, NJ
- Average snowfall days in December: 4.6 days
The month with the highest number of snowfall days is January (6.9 days).
The months with the least snowfall days are May, June, July, August, September and October (0 days).
Average daylight in December /
Average sunshine in December
Rockleigh, 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 42min
The month with the most sunshine is July (Average sunshine: 10h and 18min).
The month with the least sunshine is February (Average sunshine: 4h and 36min).
Average sunshine days in December
Rockleigh, NJ
- Average sunshine days in December: 16.8 days
The months with the most sunshine days are January and November (18.1 days).
The months with the least sunshine days are April and June (12.7 days).
Average UV index in December
Rockleigh, 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
Rockleigh, NJ
- Average cloud cover in December: 49
The months with the most cloud cover are February, March and December (Cloud cover 49).
The month with the least cloud cover is August (Cloud cover 32).
Average visibility in December
Rockleigh, NJ
- 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).
