December weather forecastSummit, NJ
December
Weather in December
December, the first month of the winter in Summit, is also an icy month, with temperature in the range of an average high of 40.8°F (4.9°C) and an average low of 29.7°F (-1.3°C).Temperature
Summit's progression into December includes a drop in the average high-temperature, from a cool 50.5°F (10.3°C) in November to a wintry 40.8°F (4.9°C). Summit's temperature drops to an average low of 29.7°F (-1.3°C) during the nights of December.Humidity
The months with the highest humidity are February and December, with an average relative humidity of 80%.Rainfall
In December, the rain falls for 11.6 days. Throughout December, 3.03" (77mm) of precipitation is accumulated. Throughout the year, there are 164.2 rainfall days, and 30.67" (779mm) of precipitation is accumulated.Snowfall
Months with snowfall in Summit are January through May, October through December. In December, it is snowing for 4 days. Throughout December, 1.61" (41mm) of snow is accumulated. In Summit, during the entire year, snow falls for 26 days and aggregates up to 11.61" (295mm) of snow.Daylight
The month with the shortest days is December, with an average of 9h and 18min of daylight.On the first day of December, sunrise is at 7:02 am and sunset at 4:30 pm. On the last day of the month, sunrise is at 7:21 am and sunset at 4:40 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 value of 2, and less, symbolizes a low threat to health from exposure to the Sun's UV rays for the ordinary person.Note: An average maximum UV index of 2 in December leads to these recommendations:
Children, babies, and those with sensitive skin should always be shielded from long periods of sun exposure. The midday Sun can be harmful due to its potent UV radiation; seek shade and reduce exposure. Arm yourself against UV rays' harm with protective apparel and UV-filtering shades. Caution! The reflection of snow 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
Summit, NJ
- Average high temperature in December: 40.8°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 (35.1°F).
- Average low temperature in December: 29.7°F
The month with the highest average low temperature is July (65.7°F).
The coldest month (with the lowest average low temperature) is January (22.5°F).
Average pressure in December
Summit, NJ
- Average pressure in December: 30.08"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
Summit, NJ
- Average wind speed in December: 7.6mph
The windiest month (with the highest average wind speed) is March (8.5mph).
The calmest month (with the lowest average wind speed) is August (5.3mph).
Average humidity in December
Summit, NJ
- Average humidity in December: 80%
The months with the highest relative humidity are February and December (80%).
The months with the lowest relative humidity are April and August (74%).
Average rainfall in December
Summit, NJ
- Average rainfall in December: 3.03"
The wettest month (with the highest rainfall) is July (3.27").
The driest month (with the least rainfall) is September (1.69").
Average rainfall days in December
Summit, NJ
- Average rainfall days in December: 11.6 days
The month with the highest number of rainy days is July (17.4 days).
The month with the least rainy days is January (8.8 days).
Average snowfall in December
Summit, NJ
- Average snowfall in December: 1.61"
The month with the highest snowfall is March (3.5").
The months with the least snowfall are June, July, August and September (0").
Average snowfall days in December
Summit, NJ
- Average snowfall days in December: 4 days
The month with the highest number of snowfall days is January (7.6 days).
The months with the least snowfall days are June, July, August and September (0 days).
Average daylight in December /
Average sunshine in December
Summit, 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 48min
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
Summit, NJ
- Average sunshine days in December: 15.6 days
The month with the most sunshine days is November (18.3 days).
The month with the least sunshine days is June (10.5 days).
Average UV index in December
Summit, 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
Summit, NJ
- Average cloud cover in December: 48
The months with the most cloud cover are February and March (Cloud cover 49).
The months with the least cloud cover are July and August (Cloud cover 34).
Average visibility in December
Summit, 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).
