December weather forecastNew Haven, CT
December
Weather in December
December welcomes the onset of winter in New Haven, Connecticut, USA, demonstrating temperatures as low as 32.5°F (0.3°C). Evenings turn cold earlier, marking the arrival of long winter nights. Despite its chilly attributes, locals enjoy the festivity brought in by the Christmas season. The first snowfall makes its entry, preparing New Haven for the beautiful, icy landscapes of the following months. By December, the city is transformed into a winter wonderland, capping the year with a snowy marvel.Temperature
Welcoming December, New Haven observes a shift in the average high-temperature, falling from November's fresh 50.7°F (10.4°C) to a cold 41.7°F (5.4°C). In New Haven, the expected average low-temperature for December is 32.5°F (0.3°C).Humidity
In December, the average relative humidity in New Haven is 75%.Rainfall
The month with the most rainfall in New Haven is December, when the rain falls for 12.5 days and typically aggregates up to 3.86" (98mm) of precipitation.Snowfall
Months with snowfall in New Haven are January through April, November and December. In December, it is snowing for 3.5 days. Throughout December, 1.34" (34mm) of snow is accumulated. Throughout the year, in New Haven, there are 23.1 snowfall days, and 9.21" (234mm) of snow is accumulated.Ocean temperature
In New Haven, the average seawater temperature in December is 48.7°F (9.3°C).Note: Engaging in a swim in 48.7°F (9.3°C) can threaten life. Brief exposure to 55.4°F (13°C) waters is uneasy, and submersion below 50°F (10°C) can lead to cold shock and disrupted breathing patterns, varying by individual.
Daylight
With an average of 9h and 18min of daylight, December has the shortest days of the year.On the first day of December in New Haven, sunrise is at 6:58 am and sunset at 4:23 pm. On the last day of the month, sunrise is at 7:17 am and sunset at 4:32 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 reading of 2, and below, represents a low health risk from exposure to the Sun's UV rays for the ordinary person.Note: The UV index of 2 during December leads to these advisories:
While most can endure approximately an hour in the sun without burning, children always require protection from sunlight. The midday Sun can be harmful due to its potent UV radiation; seek shade and reduce exposure. Tightly woven clothing, when worn loosely, shields effectively against the Sun. Be advised! The UV radiation from the Sun can be almost doubled due to the reflective properties of snow.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in December
New Haven, CT
- Average high temperature in December: 41.7°F
The warmest month (with the highest average high temperature) is July (80.4°F).
The month with the lowest average high temperature is January (35.1°F).
- Average low temperature in December: 32.5°F
The month with the highest average low temperature is July (67.6°F).
The coldest month (with the lowest average low temperature) is January (25.5°F).
Average pressure in December
New Haven, CT
- Average pressure in December: 30.06"Hg
The month with the highest atmospheric pressure is November (30.09"Hg).
The month with the lowest atmospheric pressure is June (29.93"Hg).
Average wind speed in December
New Haven, CT
- Average wind speed in December: 10.2mph
The windiest month (with the highest average wind speed) is January (10.4mph).
The calmest months (with the lowest average wind speed) are July and August (6.8mph).
Average humidity in December
New Haven, CT
- Average humidity in December: 75%
The months with the highest relative humidity are February, May and June (76%).
The months with the lowest relative humidity are April and November (72%).
Average rainfall in December
New Haven, CT
- Average rainfall in December: 3.86"
The wettest month (with the highest rainfall) is December (3.86").
The driest month (with the least rainfall) is September (2.24").
Average rainfall days in December
New Haven, CT
- Average rainfall days in December: 12.5 days
The month with the highest number of rainy days is July (18 days).
The month with the least rainy days is January (9.4 days).
Average snowfall in December
New Haven, CT
- Average snowfall in December: 1.34"
The month with the highest snowfall is March (2.8").
The months with the least snowfall are May, June, July, August, September and October (0").
Average snowfall days in December
New Haven, CT
- Average snowfall days in December: 3.5 days
The month with the highest number of snowfall days is February (7.3 days).
The months with the least snowfall days are June, July, August and September (0 days).
Average sea temperature in December
New Haven, CT
- Average sea temperature in December: 48.7°F
The best month for swimming (with the highest average sea temperature) is August (73°F).
The coldest month (with the lowest average sea temperature) is February (38.5°F).
Average daylight in December /
Average sunshine in December
New Haven, CT
- Average daylight in December: 9h and 18min
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 48min
The month with the most sunshine is July (Average sunshine: 10h and 36min).
The month with the least sunshine is February (Average sunshine: 4h and 42min).
Average sunshine days in December
New Haven, CT
- Average sunshine days in December: 15.4 days
The month with the most sunshine days is November (17.3 days).
The month with the least sunshine days is August (11.3 days).
Average UV index in December
New Haven, CT
- 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
New Haven, CT
- Average cloud cover in December: 48
The months with the most cloud cover are February and December (Cloud cover 48).
The month with the least cloud cover is August (Cloud cover 29).
Average visibility in December
New Haven, CT
- 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).
