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
With the onset of December, Old Mystic experiences a modest temperature adjustment, with the average high-temperature receding from a cool 50.9°F (10.5°C) in November to an icy 41.7°F (5.4°C). Old Mystic records an average nighttime low of 31.3°F (-0.4°C) in December.Humidity
The average relative humidity in December in Old Mystic is 76%.Rainfall
The month with the most rainfall is December, when the rain falls for 12.3 days and typically aggregates up to 3.78" (96mm) of precipitation.Snowfall
January through May, November and December are months with snowfall. In Old Mystic, Connecticut, during December, snow falls for 4.6 days and regularly aggregates up to 1.69" (43mm) of snow. In Old Mystic, during the entire year, snow falls for 26.7 days and aggregates up to 9.72" (247mm) of snow.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 7:13 am and sunset at 4:28 pm EST.
Sunshine
February and December, with an average of 4.8h of sunshine, are months with the least 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 vulnerability from exposure to the Sun's UV radiation for the average person.Note: The UV index of 2 during December translates into the following guidance:
While most can endure approximately an hour in the sun without burning, children always require protection from sunlight. The Sun's radiation is especially intense around midday; try to stay in shade during this period. A wide-brimmed hat is a staple for defending the face, eyes, ears, and neck from the Sun. Watch out! The Sun's UV radiation can be nearly magnified twofold due to snow reflection.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Is December cold?
What is the average humidity in December?
What is the wettest month?
How many days does it rain in December?
How many days does it snow in December?
What is the month with the shortest days?
How many hours of daylight does Old Mystic have in December?
When is the sunrise / sunset in December?
What are the months with the least sunshine?
How long on average sun shines in December?
What are the months with the lowest UV index in Old Mystic?
How high is the UV index in December in Old Mystic?
Average temperature in December
Old Mystic, CT
- Average high temperature in December: 41.7°F
The warmest month (with the highest average high temperature) is July (80.2°F).
The month with the lowest average high temperature is January (35.4°F).
- Average low temperature in December: 31.3°F
The month with the highest average low temperature is July (65.3°F).
The coldest month (with the lowest average low temperature) is January (24.8°F).
Average pressure in December
Old Mystic, 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
Old Mystic, CT
- Average wind speed in December: 10.1mph
The windiest month (with the highest average wind speed) is January (10.6mph).
The calmest month (with the lowest average wind speed) is August (6.8mph).
Average humidity in December
Old Mystic, CT
- Average humidity in December: 76%
The months with the highest relative humidity are June and July (79%).
The month with the lowest relative humidity is April (73%).
Average rainfall in December
Old Mystic, CT
- Average rainfall in December: 3.78"
The wettest month (with the highest rainfall) is December (3.78").
The driest month (with the least rainfall) is September (1.61").
Average rainfall days in December
Old Mystic, CT
- Average rainfall days in December: 12.3 days
The month with the highest number of rainy days is June (16.6 days).
The month with the least rainy days is January (10 days).
Average snowfall in December
Old Mystic, CT
- Average snowfall in December: 1.69"
The month with the highest snowfall is March (2.56").
The months with the least snowfall are June, July, August, September and October (0").
Average snowfall days in December
Old Mystic, CT
- Average snowfall days in December: 4.6 days
The month with the highest number of snowfall days is January (7 days).
The months with the least snowfall days are June, July, August, September and October (0 days).
Average daylight in December /
Average sunshine in December
Old Mystic, 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 24min).
The months with the least sunshine are February and December (Average sunshine: 4h and 48min).
Average sunshine days in December
Old Mystic, CT
- Average sunshine days in December: 15.5 days
The month with the most sunshine days is November (17.7 days).
The month with the least sunshine days is July (11.5 days).
Average UV index in December
Old Mystic, 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 Mystic, CT
- Average cloud cover in December: 48
The month with the most cloud cover is March (Cloud cover 49).
The month with the least cloud cover is August (Cloud cover 31).
Average visibility in December
Old Mystic, 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 Mystic, Connecticut, USA
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