Contents
- Weather in December
- Frequently asked questions
- Average temperature in December
- Average pressure in December
- Average wind speed in December
- Average humidity in December
- Average rainfall in December
- Average rainfall days in December
- Average snowfall in December
- Average snowfall days in December
- Average sea temperature in December
- Average daylight in December
- Average sunshine in December
- Average sunshine days in December
- Average UV index in December
- Average cloud cover in December
- Average visibility in December
Weather in December
Temperature
The onset of December coincides with a reduction in the average high-temperature, falling from a cool 50.9°F (10.5°C) in November to a wintry 41.9°F (5.5°C). Cos Cob records a slight downturn to an average 33.3°F (0.7°C) during the nights of December.Humidity
February, May and December, with an average relative humidity of 75%, are the most humid months in Cos Cob.Rainfall
In Cos Cob, during December, the rain falls for 12 days and regularly aggregates up to 3.86" (98mm) of precipitation. In Cos Cob, during the entire year, the rain falls for 165.6 days and collects up to 37.64" (956mm) of precipitation.Snowfall
Months with snowfall are January through April, November and December. In Cos Cob, in December, snow falls for 4.6 days, with typically accumulated 1.61" (41mm) of snow. Throughout the year, in Cos Cob, there are 25.5 snowfall days, and 8.78" (223mm) of snow is accumulated.Ocean temperature
In Cos Cob, the average seawater temperature in December is 47.1°F (8.4°C).Note: One needs to be cautious in 47.1°F (8.4°C) waters. 55.4°F (13°C) is already forbidding, but sub14°F (-10°C) can seriously disrupt your breathing and lead to a frigid shock, considering one's well-being.
Daylight
With an average of 9h and 18min of daylight, December has the shortest days of the year.On the first day of the month, sunrise is at 7:00 am and sunset at 4:26 pm. On the last day of December, in Cos Cob, sunrise is at 7:19 am and sunset at 4:36 pm EST.
Sunshine
The average sunshine in December 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 low threat to health from exposure to the Sun's UV rays for the ordinary person.Note: A daily maximum UV index of 2 in December translates into the following instructions:
Children must always have sun protection, unlike most people, who can tolerate up to an hour in the sun without any burns. Avoiding the Sun's peak radiation during midday hours is essential for health and safety. Sunglasses that ward off UVA and UVB rays play a pivotal role in reducing solar eye damage. Remember to consider! The UV radiation from the Sun can be intensified nearly twice by the reflection of snow.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Is December cold in Cos Cob?
What are the most humid months in Cos Cob?
What is the average humidity in December in Cos Cob?
How much does it rain in Cos Cob in December?
How many days does it snow in December in Cos Cob?
What is the ocean temperature in December in Cos Cob?
What is the month with the shortest days in Cos Cob?
How many hours of daylight does Cos Cob have in December?
When is the sunrise / sunset in December in Cos Cob?
How long on average sun shines in December in Cos Cob?
What are the months with the lowest UV index in Cos Cob?
How high is the UV index in December in Cos Cob?
Average temperature in December
Cos Cob, CT
- Average high temperature in December: 41.9°F
The warmest month (with the highest average high temperature) is July (82°F).
The month with the lowest average high temperature is January (35.8°F).
- Average low temperature in December: 33.3°F
The month with the highest average low temperature is July (69.1°F).
The coldest month (with the lowest average low temperature) is January (26.1°F).
Average pressure in December
Cos Cob, CT
- Average pressure in December: 30.06"Hg
The month with the highest atmospheric pressure is November (30.1"Hg).
The month with the lowest atmospheric pressure is June (29.93"Hg).
Average wind speed in December
Cos Cob, CT
- Average wind speed in December: 9.6mph
The windiest month (with the highest average wind speed) is January (9.9mph).
The calmest month (with the lowest average wind speed) is July (6.5mph).
Average humidity in December
Cos Cob, CT
- Average humidity in December: 75%
The months with the highest relative humidity are February, May and December (75%).
The month with the lowest relative humidity is August (71%).
Average rainfall in December
Cos Cob, CT
- Average rainfall in December: 3.86"
The wettest month (with the highest rainfall) is July (4.13").
The driest months (with the least rainfall) are January and February (2.4").
Average rainfall days in December
Cos Cob, CT
- Average rainfall days in December: 12 days
The month with the highest number of rainy days is July (18.1 days).
The month with the least rainy days is January (7.9 days).
Average snowfall in December
Cos Cob, CT
- Average snowfall in December: 1.61"
The month with the highest snowfall is February (2.52").
The months with the least snowfall are May, June, July, August, September and October (0").
Average snowfall days in December
Cos Cob, CT
- Average snowfall days in December: 4.6 days
The month with the highest number of snowfall days is January (7.2 days).
The months with the least snowfall days are June, July, August, September and October (0 days).
Average sea temperature in December
Cos Cob, CT
- Average sea temperature in December: 47.1°F
The best month for swimming (with the highest average sea temperature) is August (73.1°F).
The coldest month (with the lowest average sea temperature) is February (39.5°F).
Average daylight in December /
Average sunshine in December
Cos Cob, 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
Cos Cob, CT
- Average sunshine days in December: 15.2 days
The month with the most sunshine days is November (17.8 days).
The month with the least sunshine days is June (10.7 days).
Average UV index in December
Cos Cob, 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
Cos Cob, CT
- Average cloud cover in December: 49
The month with the most cloud cover is December (Cloud cover 49).
The month with the least cloud cover is August (Cloud cover 31).
Average visibility in December
Cos Cob, 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).
Cos Cob, Connecticut, USA
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