December weather forecastNorwalk, CT
December
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.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
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: 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: 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: 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: 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: 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: 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: 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: 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: 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 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: 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: 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: 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: 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).
