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
December comes with a decrease in the average high-temperature, falling from a fresh 50.9°F (10.5°C) in November to a cold 41.9°F (5.5°C). Throughout December, Old Greenwich reports a steady low-temperature average of 33.4°F (0.8°C), slightly lower than its daytime counterpart.Humidity
The months with the highest humidity are February, May, June and December, with an average relative humidity of 75%.Rainfall
In Old Greenwich, Connecticut, in December, it is raining for 12.4 days, with typically 4.09" (104mm) of accumulated precipitation. Throughout the year, there are 166.6 rainfall days, and 38.07" (967mm) of precipitation is accumulated.Snowfall
January through April, November and December are months with snowfall. In Old Greenwich, in December, snow falls for 4.4 days, with typically accumulated 1.81" (46mm) of snow. Throughout the year, there are 24.8 snowfall days, and 9.33" (237mm) of snow is accumulated.Ocean temperature
In December, the average ocean temperature in Old Greenwich is 47.1°F (8.4°C).Note: Swimming at temperatures less than 50°F (10°C) in 47.1°F (8.4°C) is feasible with the right swimsuit; if not, expect cold shock and breathlessness. A quick swim at 55.4°F (13°C) without adequate warmth can be discomforting.
Daylight
With an average of 9h and 18min of daylight, December has the shortest days of the year.On the first day of December, sunrise is at 7:00 am and sunset at 4:26 pm. On the last day of the month, sunrise is at 7:19 am and sunset at 4:36 pm EST.
Sunshine
The months with the least sunshine are February and December, with an average of 4.7h of sunshine.UV index
January through March, November and December, with an average maximum UV index of 2, are months with the lowest UV index. A UV Index value of 2, and less, symbolizes a minimal health hazard from unprotected exposure to Sun's UV rays for the ordinary person.Note: A maximum high UV index of 2 in December translates into the following recommendations:
Prolonged sun exposure generally does not trouble most people. However, it is vital to ensure protection for babies, children, and individuals with sensitive skin. It's crucial to reduce time in the direct Sun around mid-day due to the intense solar radiation. Shield yourself from the harmful effects of UV radiation with sun-protective attire, a hat, and quality sunglasses. Remember this! The UV radiation of the Sun can be nearly doubled by the reflective properties of snow.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Is it cold during December?
What are the most humid months?
What is the average humidity in December?
How much does it rain in December?
How many days does it snow in December?
How cold is the water in December?
What is the month with the shortest days?
How many hours of daylight does Old Greenwich have in December?
When is the sunrise / sunset in December?
What is the month with the least sunshine?
How long on average sun shines in December?
What is the month with the lowest UV index?
What is the UV index reading in December?
Average temperature in December
Old Greenwich, CT
- Average high temperature in December: 41.9°F
The warmest month (with the highest average high temperature) is July (81.9°F).
The month with the lowest average high temperature is January (36°F).
- Average low temperature in December: 33.4°F
The month with the highest average low temperature is July (69.3°F).
The coldest month (with the lowest average low temperature) is January (26.2°F).
Average pressure in December
Old Greenwich, 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
Old Greenwich, 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 (6.6mph).
Average humidity in December
Old Greenwich, CT
- Average humidity in December: 75%
The months with the highest relative humidity are February, May, June and December (75%).
The month with the lowest relative humidity is August (71%).
Average rainfall in December
Old Greenwich, CT
- Average rainfall in December: 4.09"
The wettest month (with the highest rainfall) is July (4.13").
The driest month (with the least rainfall) is January (2.44").
Average rainfall days in December
Old Greenwich, CT
- Average rainfall days in December: 12.4 days
The month with the highest number of rainy days is July (17.8 days).
The month with the least rainy days is January (8.6 days).
Average snowfall in December
Old Greenwich, CT
- Average snowfall in December: 1.81"
The month with the highest snowfall is February (2.6").
The months with the least snowfall are May, June, July, August, September and October (0").
Average snowfall days in December
Old Greenwich, CT
- Average snowfall days in December: 4.4 days
The month with the highest number of snowfall days is February (7.3 days).
The months with the least snowfall days are May, June, July, August, September and October (0 days).
Average sea temperature in December
Old Greenwich, 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
Old Greenwich, 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 4min
The month with the most sunshine is July (Average sunshine: 10h and 30min).
The months with the least sunshine are February and December (Average sunshine: 4h and 42min).
Average sunshine days in December
Old Greenwich, CT
- Average sunshine days in December: 14.8 days
The month with the most sunshine days is November (17.9 days).
The month with the least sunshine days is June (11.1 days).
Average UV index in December
Old Greenwich, 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
Old Greenwich, 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
Old Greenwich, 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).
Old Greenwich, Connecticut, USA
Weather forecast for your location
2. Allow the app to use your location