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 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's December weather features a mild decline in high-temperatures, reducing from a chilly 47.3°F (8.5°C) in November to a wintry 37.4°F (3°C). In the month of December, an average of 26.2°F (-3.2°C) marks the low-temperature.Humidity
In Groton, the average relative humidity in December is 78%.Rainfall
December is the month with the most rainfall. Rain falls for 9.7 days and accumulates 2.8" (71mm) of precipitation.Snowfall
Months with snowfall are January through May, October through December. In Groton, in December, during 5.3 snowfall days, 4.45" (113mm) of snow is typically accumulated. Throughout the year, there are 32.6 snowfall days, and 22.99" (584mm) of snow is accumulated.Daylight
With an average of 9h and 6min of daylight, December has the shortest days of the year.On the first day of the month, sunrise is at 6:57 am and sunset at 4:13 pm. On the last day of December, sunrise is at 7:16 am and sunset at 4:23 pm EST.
Sunshine
In December, the average sunshine is 4.9h.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 of 2, and less, symbolizes a low threat to health from unprotected exposure to Sun's UV rays for ordinary individuals.Note: In December, the maximum UV index of 2 transforms into these recommendations:
Most individuals can handle sun exposure for up to an hour without burning, but children must always be shielded from sun exposure. The midday Sun can be dangerous due to its intense radiation; always find shade and reduce exposure. Always opt for UVA and UVB-resistant sunglasses on radiant days. Pay attention! The reflection of snow can enhance the Sun's UV radiation almost double.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
How cold is it in 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 month with the shortest days?
What is the average length of the day in December?
When is the sunrise / sunset in December?
How many hours of sunshine does Groton have in December?
What are the months with the lowest UV index?
How high is the UV index in December?
Average temperature in December
Groton, MA
- Average high temperature in December: 37.4°F
The warmest month (with the highest average high temperature) is July (82°F).
The month with the lowest average high temperature is January (31.3°F).
- Average low temperature in December: 26.2°F
The month with the highest average low temperature is July (62.2°F).
The coldest month (with the lowest average low temperature) is January (19.4°F).
Average pressure in December
Groton, MA
- Average pressure in December: 30.04"Hg
The month with the highest atmospheric pressure is November (30.07"Hg).
The month with the lowest atmospheric pressure is June (29.92"Hg).
Average wind speed in December
Groton, MA
- Average wind speed in December: 8mph
The windiest month (with the highest average wind speed) is January (8.4mph).
The calmest month (with the lowest average wind speed) is August (5.4mph).
Average humidity in December
Groton, MA
- Average humidity in December: 78%
The month with the highest relative humidity is February (81%).
The month with the lowest relative humidity is April (71%).
Average rainfall in December
Groton, MA
- Average rainfall in December: 2.8"
The wettest month (with the highest rainfall) is December (2.8").
The driest month (with the least rainfall) is September (1.3").
Average rainfall days in December
Groton, MA
- Average rainfall days in December: 9.7 days
The month with the highest number of rainy days is May (15.5 days).
The month with the least rainy days is February (7.7 days).
Average snowfall in December
Groton, MA
- Average snowfall in December: 4.45"
The month with the highest snowfall is February (6.3").
The months with the least snowfall are June, July, August and September (0").
Average snowfall days in December
Groton, MA
- Average snowfall days in December: 5.3 days
The month with the highest number of snowfall days is January (8.1 days).
The months with the least snowfall days are June, July, August and September (0 days).
Average daylight in December /
Average sunshine in December
Groton, MA
- Average daylight in December: 9h and 1min
The month with the longest days is June (Average daylight: 15h and 18min).
The month with the shortest days is December (Average daylight: 9h and 6min).
- Average sunshine in December: 4h and 5min
The month with the most sunshine is August (Average sunshine: 10h and 18min).
The month with the least sunshine is February (Average sunshine: 4h and 36min).
Average sunshine days in December
Groton, MA
- Average sunshine days in December: 17.7 days
The month with the most sunshine days is November (18.4 days).
The month with the least sunshine days is May (13.5 days).
Average UV index in December
Groton, MA
- 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, MA
- Average cloud cover in December: 47
The month with the most cloud cover is March (Cloud cover 50).
The month with the least cloud cover is August (Cloud cover 34).
Average visibility in December
Groton, MA
- Average visibility in December: 6mi
The months with the highest visibility are April, October, November and December (6mi).
The months with the lowest visibility are January, February, March, May, June, July, August and September (5mi).
Groton, Massachusetts, USA
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