December weather forecastOld Lyme, CT
December
Weather in December
The first month of the winter, December, is also an icy month in Old Lyme, Connecticut, with an average temperature ranging between min 32.4°F (0.2°C) and max 41.9°F (5.5°C).Temperature
Old Lyme's December weather features a mild decline in high-temperatures, reducing from a cool 50.9°F (10.5°C) in November to an icy 41.9°F (5.5°C). Old Lyme's temperature drops to an average low of 32.4°F (0.2°C) during the nights of December.Humidity
In Old Lyme, 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 December, it is snowing for 3.2 days. Throughout December, 0.28" (7mm) of snow is accumulated. Throughout the year, there are 18.4 snowfall days, and 1.69" (43mm) of snow is accumulated.Daylight
December has the shortest days of the year, with an average of 9h and 18min of daylight.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 7:15 am and sunset at 4:30 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 low threat to health from unsafe exposure to UV radiation for the ordinary person.Note: In December, the maximum UV index of 2 translates into these guidelines:
For the majority, extended sun exposure is not of great concern. Infants and people with sensitive skin must always be protected. Midday Sun has the strongest UV rays, making it crucial to limit exposure and find shade. For a sun-safe wardrobe, go for clothes that are tightly woven and generously sized. Mind this! Nearly twice the UV radiation from the Sun can be reflected by the snow.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in December
Old 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
Old 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
Old 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
Old 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
Old 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
Old 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
Old 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
Old 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
Old Lyme, CT
- Average daylight in December: 9h and 18min
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 48min
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
Old 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
Old 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
Old 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
Old 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).
