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
The arrival of December corresponds with a reduction in the average high-temperature, down from November's fresh 50.9°F (10.5°C) to a cold 41.7°F (5.4°C). Throughout December, Old Tappan witnesses a nighttime temperature average of 30.9°F (-0.6°C).Humidity
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 are January through April, November and December. In Old Tappan, New Jersey, during December, snow falls for 4.6 days and regularly aggregates up to 1.93" (49mm) of snow. In Old Tappan, New Jersey, during the entire year, snow falls for 25.5 days and aggregates up to 10.55" (268mm) 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 7:02 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
The average sunshine in December is 4.7h.UV index
January through March, 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 low health risk from exposure to the Sun's UV radiation for average individuals.Note: The maximum UV index of 2 during December leads to these instructions:
Though the majority can handle prolonged sun exposure, it is crucial to always shield babies, children, and those with fair skin. It's crucial to reduce time in the direct Sun around mid-day due to the intense solar radiation. A wide-brimmed hat is a staple for defending the face, eyes, ears, and neck from the Sun. Warning! The reflection from snow can nearly magnify the Sun's UV radiation twofold.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
How cold does it get in December?
What is the average humidity in December?
What is the wettest month?
How much does it rain in Old Tappan in December?
How much does it snow in December?
What is the month with the shortest days?
What is the average length of the day in December?
What time are sunrise and sunset in December?
How many hours of sunshine does Old Tappan have in December?
When is the lowest UV index?
How high is the UV index in December?
Average temperature in December
Old Tappan, 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
Old Tappan, 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
Old Tappan, 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
Old Tappan, 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
Old Tappan, 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
Old Tappan, 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
Old Tappan, 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
Old Tappan, 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
Old Tappan, NJ
- Average daylight in December: 9h and 2min
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 4min
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
Old Tappan, 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
Old Tappan, 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
Old Tappan, 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
Old Tappan, 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).
Old Tappan, New Jersey, USA
Weather forecast for your location
2. Allow the app to use your location