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
In December, the average high-temperature decreases from a cool 50.5°F (10.3°C) in November to a wintry 40.8°F (4.9°C). Summit's average low-temperature for the month of December records at a subzero cold 29.7°F (-1.3°C).Humidity
The months with the highest humidity in Summit are February and December, with an average relative humidity of 80%.Rainfall
In Summit, during December, the rain falls for 11.6 days and regularly aggregates up to 3.03" (77mm) of precipitation. In Summit, during the entire year, the rain falls for 164.2 days and collects up to 30.67" (779mm) of precipitation.Snowfall
Months with snowfall in Summit are January through May, October through December. In Summit, in December, snow falls for 4 days, with typically accumulated 1.61" (41mm) of snow. Throughout the year, there are 26 snowfall days, and 11.61" (295mm) of snow is accumulated.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 4:30 pm. On the last day of December, sunrise is at 7:21 am and sunset at 4:40 pm EST.
Sunshine
In Summit, New Jersey, the average sunshine in December is 4.8h.UV index
The months with the lowest UV index in Summit 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 threat to health from unprotected exposure to Sun's UV rays for the average person.Note: The maximum UV index of 2 during December leads to these instructions:
Prolonged sun exposure should always be prevented in babies, children, and those with sensitive skin. The Sun's harshest UV rays are around midday; it's wise to seek shade and limit time outdoors. Arm yourself against UV rays' harm with protective apparel and UV-filtering shades. Guard yourself! Snow reflection can almost double the UV radiation from the Sun.
Frequently asked questions
Is December cold in Summit?
What are the most humid months in Summit?
What is the average humidity in December in Summit?
How much does it rain in Summit in December?
How many days does it snow in December in Summit?
What is the month with the shortest days in Summit?
What is the average length of the day in December in Summit?
When are sunrise and sunset in December in Summit?
How long on average sun shines in December in Summit?
When is the lowest UV index in Summit?
What is the UV index reading in December in Summit?
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 2min
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 5min
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).
Summit, New Jersey, USA
Weather forecast for your location
2. Allow the app to use your location
