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
December brings a decrease in the average high-temperature, shifting from a fresh 50.9°F (10.5°C) in November to an icy 41.9°F (5.5°C). In December, the average low-temperature is a still wintry 32.4°F (0.2°C).Humidity
The average relative humidity in December is 75%.Rainfall
December is the month with the most rainfall. Rain falls for 9.5 days and accumulates 0.94" (24mm) of precipitation.Snowfall
January through March, November and December are months with snowfall. In South Lyme, Connecticut, during December, snow falls for 3.2 days and regularly aggregates up to 0.28" (7mm) of snow. Throughout the year, there are 18.4 snowfall days, and 1.69" (43mm) of snow is accumulated.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 6:56 am and sunset at 4:20 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 4.8h 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 minimal health hazard from unsafe exposure to UV radiation for average individuals.Note: The maximum daily UV index of 2 in December converts into the following recommendations:
Although the majority can endure up to an hour in the sun without burns, children always require sun protection. Considering the harmful UV rays from the Sun during midday, it's essential to reduce exposure. Protect your eyes, ears, face, and neck from the Sun by wearing a wide-brimmed hat. Take into account! The reflection from snow can nearly double the Sun's UV radiation intensity.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Is December cold in South Lyme?
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?
What is the average length of the day in December in South Lyme?
When are sunrise and sunset in December?
What is the month with the least sunshine?
How many hours of sunshine does South Lyme have in December?
What are the months with the lowest UV index?
How high is the UV index in December?
Average temperature in December
South Lyme, CT
- Average high temperature in December: 41.9°F
The warmest month (with the highest average high temperature) is July (79.5°F).
The month with the lowest average high temperature is January (35.4°F).
- Average low temperature in December: 32.4°F
The month with the highest average low temperature is July (66.4°F).
The coldest month (with the lowest average low temperature) is January (25.7°F).
Average pressure in December
South Lyme, 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
South Lyme, CT
- Average wind speed in December: 10.7mph
The windiest month (with the highest average wind speed) is January (11.1mph).
The calmest month (with the lowest average wind speed) is July (7.2mph).
Average humidity in December
South Lyme, CT
- Average humidity in December: 75%
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
South Lyme, CT
- Average rainfall in December: 0.94"
The wettest month (with the highest rainfall) is December (0.94").
The driest month (with the least rainfall) is September (0.35").
Average rainfall days in December
South Lyme, CT
- Average rainfall days in December: 9.5 days
The month with the highest number of rainy days is July (11.5 days).
The months with the least rainy days are February and November (6.6 days).
Average snowfall in December
South Lyme, CT
- Average snowfall in December: 0.28"
The month with the highest snowfall is March (0.63").
The months with the least snowfall are April, May, June, July, August, September and October (0").
Average snowfall days in December
South Lyme, CT
- Average snowfall days in December: 3.2 days
The month with the highest number of snowfall days is January (5.4 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
South Lyme, 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 months with the most sunshine are July and August (Average sunshine: 10h and 36min).
The months with the least sunshine are February and December (Average sunshine: 4h and 48min).
Average sunshine days in December
South Lyme, CT
- Average sunshine days in December: 19.7 days
The month with the most sunshine days is November (21.1 days).
The month with the least sunshine days is July (15.8 days).
Average UV index in December
South Lyme, 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
South Lyme, CT
- Average cloud cover in December: 48
The months with the most cloud cover are February and December (Cloud cover 48).
The month with the least cloud cover is August (Cloud cover 28).
Average visibility in December
South Lyme, 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).
South Lyme, Connecticut, USA
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