New Haven
Connecticut, USA
Long-term weather forecast
Long-term weather forecast

December weather forecast and climate
New Haven, CT

A scenic shot from above of the greeny New Haven Green in Connecticut, with the rest of the city and a far away dramatic landscape
A scenic shot from above of the greeny New Haven Green in Connecticut, with the rest of the city and a far away dramatic landscape
The first month of the winter, December, is still a chilly month in New Haven, Connecticut, with average temperature varying between 43°F (6.1°C) and 28.4°F (-2°C).

Temperature

In New Haven, the average high-temperature decreases, from a cool 53.4°F (11.9°C) in November, to a frosty 43°F (6.1°C). In New Haven, Connecticut, the average low-temperature is 28.4°F (-2°C).

Rainfall

In December, the rain falls for 12 days. Throughout December, 3.6" (91.7mm) of precipitation is accumulated. In New Haven, during the entire year, the rain falls for 119 days and collects up to 47.1" (1196.6mm) of precipitation.

Ocean temperature

In New Haven, the average water temperature is 48.7°F (9.3°C). At temperatures below 50°F (10°C), swimming in a suitably protected swimsuit is feasible; otherwise, cold shock and loss of breathing control are imminent. Even a short swim, without thermal protection, at temperatures around 55.4°F (13°C) is not comfortable.

Daylight

With an average of 9.2h of daylight, December has the shortest days of the year in New Haven.

Sunshine

November and December, with an average of 5h of sunshine, are months with the least sunshine.

UV index

The month with the lowest UV index is December, with an average maximum UV index of 1. A UV Index estimate of 2, and below, represents a minimal health vulnerability from unprotected exposure to the Sun's UV rays for average individuals.
In December, the average maximum UV index of 1 translate into the following recommendations:
Extended sun exposure is not an issue for the majority. Children, infants, and fair-skinned individuals always need to be protected. The solar radiation is most powerful near the mid-day, so the exposure to the direct Sun should be reduced accordingly. On bright days sunglasses that block both UVA and UVB rays should be worn. A hat with a wide brim is extremely helpful, as it can prevent roughly 50% of UV radiation from reaching the eyes.

What is the temperature in December in New Haven?

In December, in New Haven, the average high-temperature is 43°F (6.1°C), and the average low-temperature is 28.4°F (-2°C).

How many days does it rain in December in New Haven?

In New Haven, in December, during 12 rainfall days, 3.6" (91.7mm) of precipitation is typically accumulated.

What is the ocean temperature in December in New Haven?

In December, the average ocean temperature is 48.7°F (9.3°C). Swimming in 48.7°F (9.3°C) is considered dangerous. Unprotected immersion in temperatures below 50°F (10°C) causes quickly maximum intensity cold shock with hyperventilation.

What is the month with the shortest days in New Haven?

With an average of 9.2h of daylight, December has the shortest days of the year in New Haven, Connecticut.

What is the average length of the day in December in New Haven?

In December, the average length of the day in New Haven is 9.2h.

What is the month with the least sunshine in New Haven?

November and December, with an average of 5h of sunshine, are months with the least sunshine in New Haven.

How many hours of sunshine does New Haven have in December?

In New Haven, the average sunshine in December is 5h.

When is the lowest UV index in New Haven?

With an average maximum UV index of 1, December is the month with the lowest UV index in New Haven.

What is the UV index reading in December in New Haven?

The average daily maximum UV index in December is 1. A UV Index of 2, and less, symbolizes a minimal health vulnerability from the exposure to the Sun's UV radiation.
Average temperature in December - New Haven, CT
  • Average high temperature in December: 42.9°F

The warmest month (with the highest average high temperature) is July (82.5°F).
The month with the lowest average high temperature is January (37.8°F).

  • Average low temperature in December: 28.4°F

The month with the highest average low temperature is July (65.5°F).
The coldest month (with the lowest average low temperature) is January (22.2°F).

Average rainfall in December - New Haven, CT
  • Average rainfall in December: 3.6"

Wettest months (with the highest rainfall) are April and September (4.4").
The driest month (with the lowest rainfall) is February (2.9").

Average rainfall days in December - New Haven, CT
  • Average rainfall days in December: 12 days

The month with the highest number of rainy days is December (12 days).
The month with the lowest number of rainy days is October (7 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: 9.2h

The month with the longest days is June (Average daylight: 15.1h).
The month with shortest days is December (Average daylight: 9.2h).

  • Average sunshine in December: 5h

Months with most sunshine are May, June and July (Average sunshine: 9h).
Months with least sunshine are November and December (Average sunshine: 5).

Average UV index in December - New Haven, CT
  • Average UV index in December: 1

Months with the highest UV index are June, July and August (UV index 8).
The month with the lowest UV index is December (UV index 1).