December weather forecastHaddam, CT
December
Weather in December
The first month of the winter, December, is also an icy month in Haddam, Connecticut, with an average temperature fluctuating between 40.6°F (4.8°C) and 30°F (-1.1°C).Temperature
The shift from November to December corresponds with a decrease in the average high-temperature, down to an icy 40.6°F (4.8°C) from a fresh 50°F (10°C). During December, the temperature in Haddam is averaged to a low of 30°F (-1.1°C) at night.Humidity
The average relative humidity in December is 76%.Rainfall
In December, the rain falls for 8.6 days. Throughout December, 1.14" (29mm) of precipitation is accumulated. Throughout the year, there are 109.9 rainfall days, and 11.14" (283mm) of precipitation is accumulated.Snowfall
Months with snowfall are January through May, November and December. In Haddam, in December, during 3.7 snowfall days, 0.55" (14mm) of snow is typically accumulated. Throughout the year, there are 19.9 snowfall days, and 3.7" (94mm) of snow is accumulated.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 6:57 am and sunset at 4:21 pm. On the last day of December, sunrise is at 7:16 am and sunset at 4:30 pm EST.
Sunshine
In December, the average sunshine is 4.6h.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 of 2, and less, symbolizes a minimal health vulnerability from unprotected exposure to Sun's UV rays for average individuals.Note: The UV index of 2 in December translates into these instructions:
Despite the majority tolerating prolonged sun exposure, those with sensitive skin, infants, and children demand continual protection. The Sun's most harmful UV rays are emitted around midday; avoid staying outdoors for long during this time. A wide-brimmed hat provides unparalleled sun protection for sensitive areas like the eyes, ears, and neck. Be on the lookout! Nearly twofold UV radiation from the Sun can be reflected by snow.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in December
Haddam, CT
- Average high temperature in December: 40.6°F
The warmest month (with the highest average high temperature) is July (82.6°F).
The month with the lowest average high temperature is January (34.7°F).
- Average low temperature in December: 30°F
The month with the highest average low temperature is July (63.9°F).
The coldest month (with the lowest average low temperature) is January (22.8°F).
Average pressure in December
Haddam, 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
Haddam, CT
- Average wind speed in December: 8.4mph
The windiest months (with the highest average wind speed) are January and March (8.6mph).
The calmest months (with the lowest average wind speed) are July and August (5.7mph).
Average humidity in December
Haddam, CT
- Average humidity in December: 76%
The month with the highest relative humidity is February (78%).
The month with the lowest relative humidity is April (72%).
Average rainfall in December
Haddam, CT
- Average rainfall in December: 1.14"
The wettest month (with the highest rainfall) is July (1.18").
The driest month (with the least rainfall) is September (0.39").
Average rainfall days in December
Haddam, CT
- Average rainfall days in December: 8.6 days
The month with the highest number of rainy days is July (12.7 days).
The month with the least rainy days is January (5.9 days).
Average snowfall in December
Haddam, CT
- Average snowfall in December: 0.55"
The month with the highest snowfall is March (1.14").
The months with the least snowfall are June, July, August, September and October (0").
Average snowfall days in December
Haddam, CT
- Average snowfall days in December: 3.7 days
The month with the highest number of snowfall days is February (5.2 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
Haddam, CT
- Average daylight in December: 9h and 12min
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 36min
The months with the most sunshine are July and August (Average sunshine: 10h and 6min).
The month with the least sunshine is February (Average sunshine: 4h and 30min).
Average sunshine days in December
Haddam, CT
- Average sunshine days in December: 19.2 days
The month with the most sunshine days is November (20.9 days).
The month with the least sunshine days is July (16.3 days).
Average UV index in December
Haddam, 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
Haddam, CT
- Average cloud cover in December: 50
The months with the most cloud cover are February and March (Cloud cover 51).
The month with the least cloud cover is August (Cloud cover 35).
Average visibility in December
Haddam, CT
- Average visibility in December: 6mi
The months with the highest visibility are January, March, April, September, October, November and December (6mi).
The months with the lowest visibility are February, May, June, July and August (5mi).
