December weather forecast
Norwalk, CT

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The tourist attraction spot of a stone house home to the Sheffield Island lighthouse in Norwalk, Connecticut
The tourist attraction spot of a stone house home to the Sheffield Island lighthouse in Norwalk, Connecticut

Weather in December

December marks the onset of winter and festive cheer in Norwalk. The weather in December considerably drops from November, with high temperatures reaching 41.9°F (5.5°C) and low temperatures falling to 32.9°F (0.5°C). Along with the festive excitement, residents brace for the cold, chilly winds, frosty mornings, and possibilities of snowfall characteristic to the month, rounding off the year on a wintry note.

Temperature

Setting in of December comes with a decrease in the average high-temperature, moving from a cool 50.9°F (10.5°C) in November to a cold 41.9°F (5.5°C). In Norwalk, the month of December brings a consistent average low-temperature of 32.9°F (0.5°C), slightly cooler than its daytime highs.

Humidity

In December, the average relative humidity in Norwalk is 75%.

Rainfall

In Norwalk, in December, during 12.2 rainfall days, 3.98" (101mm) of precipitation is typically accumulated. Throughout the year, there are 166.3 rainfall days, and 37.87" (962mm) of precipitation is accumulated.

Snowfall

January through April, November and December are months with snowfall. In Norwalk, during December, snow falls for 3.6 days and regularly aggregates up to 1.77" (45mm) of snow. Throughout the year, in Norwalk, there are 24.6 snowfall days, and 9.61" (244mm) of snow is accumulated.

Ocean temperature

In December, the average ocean temperature is 48°F (8.9°C).
Note: Beware of 48°F (8.9°C) waters at 55.4°F (13°C), they're uninviting, and a dip below 50°F (10°C) has risks of breath loss and cold shock, contingent on health.

Daylight

December has the shortest days of the year, with an average of 9h and 18min of daylight.
On the first day of the month, sunrise is at 7:00 am and sunset at 4:25 pm. On the last day of December, in Norwalk, sunrise is at 7:18 am and sunset at 4:35 pm EST.

Sunshine

In Norwalk, the average sunshine in December is 4.8h.

UV index

The months with the lowest UV index in Norwalk, Connecticut, 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 low threat to health from exposure to the Sun's UV rays for ordinary individuals.
Note: A typical high UV index of 2 in December suggests the following recommendations:
Extended exposure to the sun should always be avoided by children, infants, and those with sensitive skin. The midday Sun can be dangerous due to its intense radiation; always find shade and reduce exposure. Combat UV radiation's detrimental effects with sun-safe clothing and UV-blocking eyewear. On your guard! Snow's reflection can almost double the intensity of the Sun's UV radiation.
Updated: Feb 10, 2024
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate

Frequently asked questions

How cold is December in Norwalk?

Norwalk in December has an average high-temperature of 41.9°F (5.5°C) and an average low-temperature of 32.9°F (0.5°C). The average heat index (a.k.a. 'feels like', 'apparent temperature'), which combines air temperature and relative humidity, in July is estimated at 86°F (30°C).

What is the average humidity in December in Norwalk?

In December, the average relative humidity in Norwalk, Connecticut, is 75%.

How much does it rain in Norwalk in December?

In December, the rain falls for 12.2 days. Throughout December, 3.98" (101mm) of precipitation is accumulated.

How much does it snow in Norwalk in December?

In Norwalk, in December, snow falls for 3.6 days, with typically accumulated 1.77" (45mm) of snow.

What is the ocean temperature in December in Norwalk?

In Norwalk, the average seawater temperature in December is 48°F (8.9°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.

What is the month with the shortest days in Norwalk?

With an average of 9h and 18min of daylight, December has the shortest days of the year.

What is the average length of the day in December in Norwalk?

The average day length in December is 9h and 16min.

What time are sunrise and sunset in December in Norwalk?

In December, on the first day of the month, sunrise is at 7:00 am and sunset at 4:25 pm. On the last day of the month, in Norwalk, Connecticut, sunrise is at 7:18 am and sunset at 4:35 pm EST.

How long on average sun shines in December in Norwalk?

In Norwalk, the average sunshine duration in December is 4.8h.

When is the lowest UV index in Norwalk?

The months with the lowest UV index in Norwalk are January through March, November and December, with an average maximum UV index of 2.

What is the UV index intensity in December in Norwalk?

In December, the average daily maximum UV index is 2. A UV Index reading of 2, and below, represents a minimal hazard to health from unsafe exposure to Sun's UV rays.
Average humidity
Average rainfall days
Average snowfall days
Average daylight
Average sunshine
Average sunshine days
Average UV index
Average cloud cover
Average visibility

Average temperature in December
Norwalk, CT

Average temperature in December - Norwalk, CT
  • Average high temperature in December: 41.9°F

The warmest month (with the highest average high temperature) is July (81.1°F).
The month with the lowest average high temperature is January (35.8°F).

  • Average low temperature in December: 32.9°F

The month with the highest average low temperature is July (68.2°F).
The coldest month (with the lowest average low temperature) is January (26.4°F).

Average pressure in December
Norwalk, CT

Average pressure in December - Norwalk, 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
Norwalk, CT

Average wind speed in December - Norwalk, CT
  • Average wind speed in December: 9.8mph

The windiest month (with the highest average wind speed) is January (10.1mph).
The calmest month (with the lowest average wind speed) is July (6.5mph).

Average humidity in December
Norwalk, CT

Average humidity in December - Norwalk, 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
Norwalk, CT

Average rainfall in December - Norwalk, CT
  • Average rainfall in December: 3.98"

The wettest month (with the highest rainfall) is July (4.13").
The driest months (with the least rainfall) are January and February (2.36").

Average rainfall days in December
Norwalk, CT

Average rainfall days in December - Norwalk, CT
  • Average rainfall days in December: 12.2 days

The month with the highest number of rainy days is July (18.1 days).
The month with the least rainy days is January (8.3 days).

Average snowfall in December
Norwalk, CT

Average snowfall in December - Norwalk, CT
  • Average snowfall in December: 1.77"

The month with the highest snowfall is February (2.83").
The months with the least snowfall are May, June, July, August, September and October (0").

Average snowfall days in December
Norwalk, CT

Average snowfall days in December - Norwalk, CT
  • Average snowfall days in December: 3.6 days

The month with the highest number of snowfall days is February (7.4 days).
The months with the least snowfall days are June, July, August and September (0 days).

Average sea temperature in December
Norwalk, CT

Average sea temperature in December - Norwalk, CT
  • Average sea temperature in December: 48.1°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 (39°F).

Average daylight in December /
Average sunshine in December
Norwalk, CT

Average daylight in December / Average sunshine in December - Norwalk, CT
  • Average daylight in December: 9h and 2min

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 5min

The month with the most sunshine is July (Average sunshine: 10h and 30min).
The month with the least sunshine is February (Average sunshine: 4h and 42min).

Average sunshine days in December
Norwalk, CT

Average sunshine days in December - Norwalk, CT
  • Average sunshine days in December: 15.4 days

The month with the most sunshine days is January (17.8 days).
The month with the least sunshine days is June (10 days).

Average UV index in December
Norwalk, CT

Average UV index in December - Norwalk, 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
Norwalk, CT

Average cloud cover in December - Norwalk, CT
  • Average cloud cover in December: 48

The months with the most cloud cover are February, March and December (Cloud cover 48).
The month with the least cloud cover is August (Cloud cover 30).

Average visibility in December
Norwalk, CT

Average visibility in December - Norwalk, 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).

Norwalk, Connecticut, USA

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