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
Greenwich's weather in December involves a decrease in the average high-temperature, moving down from November's fresh 50.9°F (10.5°C) to a cold 41.9°F (5.5°C). Nighttime temperature reflects an average dip to a still icy 33.3°F (0.7°C) in December, subtly cooler than its daytime highs.Humidity
The months with the highest humidity are February, May and December, with an average relative humidity of 75%.Rainfall
In December, the rain falls for 12 days. Throughout December, 3.86" (98mm) of precipitation is accumulated. Throughout the year, in Greenwich, Connecticut, there are 165.6 rainfall days, and 37.64" (956mm) of precipitation is accumulated.Snowfall
Months with snowfall are January through April, November and December. In Greenwich, during December, snow falls for 4.6 days and regularly aggregates up to 1.61" (41mm) of snow. Throughout the year, there are 25.5 snowfall days, and 8.78" (223mm) of snow is accumulated.Ocean temperature
In Greenwich, the average seawater temperature in December is 47.1°F (8.4°C).Note: Staying in 47.1°F (8.4°C) waters for just a few moments at 55.4°F (13°C) can be harrowing, and below 50°F (10°C) poses breathing and cold shock risks, depending on individual tolerance.
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, sunrise is at 7:19 am and sunset at 4:36 pm EST.
Sunshine
In Greenwich, the average sunshine in December is 4.8h.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 of 2, and less, symbolizes a low health risk from unprotected exposure to Sun's UV rays for the average person.Note: In December, the UV index of 2 transforms into the following advice:
While extended sun exposure does not significantly affect most people, those with sensitive skin, children, and infants should always be protected. To guard against the harmful effects of the Sun, minimize exposure during midday. Prioritize a wide-brim hat for comprehensive sun defense for your face, neck, eyes, and ears. Attention! Nearly twice the Sun's UV radiation can be reflected by snow.
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Data Sources | Weather Forecasting & Climate
Frequently asked questions
How cold is December in Greenwich?
What is the most humid month in Greenwich?
What is the average humidity in December in Greenwich?
How much does it rain in Greenwich in December?
How much does it snow in Greenwich in December?
How cold is the water in December in Greenwich?
What is the month with the shortest days in Greenwich?
What is the average length of the day in December in Greenwich?
When are sunrise and sunset in December in Greenwich?
How many hours of sunshine does Greenwich have in December?
What are the months with the lowest UV index in Greenwich?
How high is the UV index in December in Greenwich?
Average temperature in December
Greenwich, 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
Greenwich, 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
Greenwich, 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
Greenwich, 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
Greenwich, 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
Greenwich, 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
Greenwich, 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
Greenwich, 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
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
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 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
Greenwich, 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
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
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
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).
Greenwich, Connecticut, USA
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