December weather forecastChatham, NJ
December
Weather in December
December, the first month of the winter in Chatham, is also a wintry month, with an average temperature fluctuating between 40.8°F (4.9°C) and 29.7°F (-1.3°C).Temperature
The commencement of December indicates a shift in the average high-temperature, receding from November's fresh 50.5°F (10.3°C) to an icy 40.8°F (4.9°C). In the month of December, the temperature in Chatham generally rests at an average low of 29.7°F (-1.3°C).Humidity
The months with the highest humidity are February and December, with an average relative humidity of 80%.Rainfall
In Chatham, in December, it is raining for 11.6 days, with typically 3.03" (77mm) of accumulated precipitation. In Chatham, during the entire year, the rain falls for 164.2 days and collects up to 30.67" (779mm) of precipitation.Snowfall
January through May, October through December are months with snowfall. In December, it is snowing for 4 days. Throughout December, 1.61" (41mm) of snow is accumulated. Throughout the year, there are 26 snowfall days, and 11.61" (295mm) of snow is accumulated.Daylight
The month with the shortest days in Chatham is December, with an average of 9h and 18min of daylight.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 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 estimate of 2, and below, represents a minimal health vulnerability from exposure to the Sun's UV radiation for the ordinary person.Note: The average daily UV index of 2 in December transforms into the following instructions:
For the majority, extended sun exposure is not of great concern. Infants and people with sensitive skin must always be protected. The midday Sun can be dangerous due to its intense radiation; always find shade and reduce exposure. Consider a wide-brim hat essential for effective sun defense covering your face, neck, and eyes. Notice! The UV radiation of the Sun can be intensified nearly twofold due to the reflective quality of snow.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in December
Chatham, 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
Chatham, 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
Chatham, 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
Chatham, 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
Chatham, 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
Chatham, 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
Chatham, 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
Chatham, 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
Chatham, 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
Chatham, 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
Chatham, 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
Chatham, 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
Chatham, 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).
