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
Groton, Connecticut, experiences a temperature shift at the start of December, with average high-temperatures adjusting from a fresh 50.9°F (10.5°C) in November to a cold 41.9°F (5.5°C). December notes an average low temperature of 33.3°F (0.7°C), subtly down from the daytime highs.Humidity
In December, the average relative humidity is 75%.Rainfall
The month with the most rainfall is December, when the rain falls for 13.4 days and typically aggregates up to 3.86" (98mm) of precipitation.Snowfall
Months with snowfall in Groton are January through April, November and December. In Groton, Connecticut, in December, during 4.8 snowfall days, 1.22" (31mm) of snow is typically accumulated. In Groton, during the entire year, snow falls for 24 days and aggregates up to 7.68" (195mm) of snow.Ocean temperature
In Groton, in December, the average water temperature is 48.9°F (9.4°C).Note: Without suitable protection, venturing into 48.9°F (9.4°C) waters cooler than 50°F (10°C) can lead to pronounced cold shock and rapid breaths.
Daylight
The month with the shortest days is December, with an average of 9h and 12min of daylight.On the first day of the month, sunrise is at 6:55 am and sunset at 4:19 pm. On the last day of December, sunrise is at 7:14 am and sunset at 4:29 pm EST.
Sunshine
The months with the least sunshine are February and December, with an average of 4.9h 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 estimate of 2, and below, represents a low health risk from exposure to the Sun's UV rays for the average person.Note: In December, an average UV index of 2 transforms into the following instructions:
Most individuals face no major issues with lengthy exposure to the sun, but children, infants, and individuals with fair skin always require protection. Direct Sun exposure should be minimized especially during midday when radiation is most intense. Shield yourself from the harmful effects of UV radiation with sun-protective attire, a hat, and quality sunglasses. Be prepared! The intensity of the Sun's UV radiation can be amplified nearly double due to snow reflection.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
How cold is December?
What is the average humidity in December?
What is the wettest month?
How much does it rain in December?
How many days does it snow in December?
What is the ocean temperature in December?
What is the month with the shortest days?
What is the average length of the day in December?
When is the sunrise / sunset in December?
What are the months with the least sunshine?
How many hours of sunshine does Groton have in December?
What is the month with the lowest UV index?
What is the UV index reading in December in Groton?
Average temperature in December
Groton, CT
- Average high temperature in December: 41.9°F
The warmest month (with the highest average high temperature) is July (78.6°F).
The month with the lowest average high temperature is January (36.1°F).
- Average low temperature in December: 33.3°F
The month with the highest average low temperature is July (66.7°F).
The coldest month (with the lowest average low temperature) is January (26.2°F).
Average pressure in December
Groton, CT
- Average pressure in December: 30.05"Hg
The month with the highest atmospheric pressure is November (30.08"Hg).
The month with the lowest atmospheric pressure is June (29.93"Hg).
Average wind speed in December
Groton, CT
- Average wind speed in December: 11.5mph
The windiest month (with the highest average wind speed) is January (11.9mph).
The calmest months (with the lowest average wind speed) are July and August (7.8mph).
Average humidity in December
Groton, CT
- Average humidity in December: 75%
The month with the highest relative humidity is June (80%).
The months with the lowest relative humidity are January, March, April and November (74%).
Average rainfall in December
Groton, CT
- Average rainfall in December: 3.86"
The wettest month (with the highest rainfall) is December (3.86").
The driest month (with the least rainfall) is September (1.65").
Average rainfall days in December
Groton, CT
- Average rainfall days in December: 13.4 days
The month with the highest number of rainy days is July (15.8 days).
The month with the least rainy days is February (9.5 days).
Average snowfall in December
Groton, CT
- Average snowfall in December: 1.22"
The month with the highest snowfall is March (2.56").
The months with the least snowfall are May, June, July, August, September and October (0").
Average snowfall days in December
Groton, CT
- Average snowfall days in December: 4.8 days
The month with the highest number of snowfall days is February (6.8 days).
The months with the least snowfall days are June, July, August, September and October (0 days).
Average sea temperature in December
Groton, CT
- Average sea temperature in December: 48.9°F
The best month for swimming (with the highest average sea temperature) is August (72.1°F).
The coldest month (with the lowest average sea temperature) is February (38.8°F).
Average daylight in December /
Average sunshine in December
Groton, CT
- Average daylight in December: 9h and 1min
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 12min).
- Average sunshine in December: 4h and 5min
The month with the most sunshine is August (Average sunshine: 10h and 36min).
The months with the least sunshine are February and December (Average sunshine: 4h and 54min).
Average sunshine days in December
Groton, CT
- Average sunshine days in December: 13.9 days
The month with the most sunshine days is November (16.5 days).
The month with the least sunshine days is February (12.5 days).
Average UV index in December
Groton, 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
Groton, CT
- Average cloud cover in December: 47
The months with the most cloud cover are February, March and December (Cloud cover 47).
The month with the least cloud cover is August (Cloud cover 29).
Average visibility in December
Groton, 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).
Groton, Connecticut, USA
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