December weather forecastWashington, NJ
December
Weather in December
December, the first month of the winter in Washington, is also a wintry month, with an average temperature fluctuating between 40.1°F (4.5°C) and 28.4°F (-2°C).Temperature
The arrival of December signals a shift in temperature, down from a chilly 49.8°F (9.9°C) in November to a cold 40.1°F (4.5°C). Washington's average low-temperature in the month of December is recorded at a subzero cold 28.4°F (-2°C).Humidity
The average relative humidity in December is 80%.Rainfall
In December, the rain falls for 11.7 days. Throughout December, 2.8" (71mm) of precipitation is accumulated. In Washington, during the entire year, the rain falls for 157.6 days and collects up to 28.7" (729mm) of precipitation.Snowfall
Months with snowfall are January through May, October through December. In Washington, during December, snow falls for 4.9 days and regularly aggregates up to 2.4" (61mm) of snow. Throughout the year, there are 30.4 snowfall days, and 14.76" (375mm) of snow is accumulated.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 7:05 am and sunset at 4:33 pm. On the last day of December, sunrise is at 7:23 am and sunset at 4:42 pm EST.
Sunshine
In Washington, 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 estimate of 2, and below, represents a minimal health hazard from unprotected exposure to Sun's UV rays for average individuals.Note: In December, the maximum UV index of 2 transforms into these recommendations:
While most people can stay under the sun for an hour without burning, children must always be guarded against sun exposure. To prevent harmful UV exposure, minimize direct contact with the Sun around midday. On sunny days, it's ideal to wear sunglasses that filter out UVA and UVB rays. Keep in mind! Snow's reflective quality 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
Average temperature in December
Washington, NJ
- Average high temperature in December: 40.1°F
The warmest month (with the highest average high temperature) is July (83.7°F).
The month with the lowest average high temperature is January (34°F).
- Average low temperature in December: 28.4°F
The month with the highest average low temperature is July (63°F).
The coldest month (with the lowest average low temperature) is January (21.6°F).
Average pressure in December
Washington, NJ
- 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
Washington, NJ
- Average wind speed in December: 7.3mph
The windiest month (with the highest average wind speed) is March (8.1mph).
The calmest month (with the lowest average wind speed) is August (4.8mph).
Average humidity in December
Washington, NJ
- Average humidity in December: 80%
The month with the highest relative humidity is February (81%).
The month with the lowest relative humidity is April (76%).
Average rainfall in December
Washington, NJ
- Average rainfall in December: 2.8"
The wettest month (with the highest rainfall) is July (2.87").
The driest month (with the least rainfall) is September (1.54").
Average rainfall days in December
Washington, NJ
- Average rainfall days in December: 11.7 days
The month with the highest number of rainy days is May (16.5 days).
The month with the least rainy days is January (8.1 days).
Average snowfall in December
Washington, NJ
- Average snowfall in December: 2.4"
The month with the highest snowfall is February (3.82").
The months with the least snowfall are June, July, August and September (0").
Average snowfall days in December
Washington, NJ
- Average snowfall days in December: 4.9 days
The month with the highest number of snowfall days is January (8.4 days).
The months with the least snowfall days are June, July, August and September (0 days).
Average daylight in December /
Average sunshine in December
Washington, NJ
- Average daylight in December: 9h and 18min
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 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
Washington, NJ
- Average sunshine days in December: 16 days
The month with the most sunshine days is November (17.5 days).
The month with the least sunshine days is April (11.8 days).
Average UV index in December
Washington, NJ
- Average UV index in December: 2
The months with the highest UV index are June and July (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
Washington, NJ
- Average cloud cover in December: 49
The month with the most cloud cover is February (Cloud cover 50).
The month with the least cloud cover is July (Cloud cover 34).
Average visibility in December
Washington, NJ
- Average visibility in December: 5mi
The months with the highest visibility are April and November (6mi).
The months with the lowest visibility are January, February, March, May, June, July, August, September, October and December (5mi).
