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
The transition into December involves a small decrease in the average high-temperature, dipping slightly from a fresh 51.3°F (10.7°C) in November to a frosty 43.7°F (6.5°C). A modest decline from daytime high temperatures is noticed in December, marking the average low at a cold 36.5°F (2.5°C).Humidity
In December, the average relative humidity is 75%.Rainfall
In December, the rain falls for 14.2 days. Throughout December, 3.62" (92mm) of precipitation is accumulated. Throughout the year, there are 157.2 rainfall days, and 31.77" (807mm) of precipitation is accumulated.Snowfall
January through April and December are months with snowfall. December is the first month it typically snows. Throughout December, in the average 4.4 snowfall days, it receives 0.87" (22mm) of snow. In Hyannis Port, during the entire year, snow falls for 24.1 days and aggregates up to 6.1" (155mm) of snow.Daylight
With an average of 9h and 12min of daylight, December has the shortest days of the year.On the first day of December, sunrise is at 6:49 am and sunset at 4:11 pm. On the last day of the month, sunrise is at 7:07 am and sunset at 4:21 pm EST.
Sunshine
The month with the least sunshine is December, with an average of 4.6h 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 in Hyannis Port, Massachusetts. A UV Index estimate of 2, and below, represents a minimal health vulnerability from exposure to the Sun's UV rays for the average person.Note: The maximum daily UV index of 2 during December translates into the following directions:
Prolonged exposure to sunlight rarely troubles the majority, but constant protection is vital for babies, children, and fair-skinned people. During midday, the Sun's radiation is strongest, and it's advisable to reduce direct exposure. Consider a wide-brim hat essential for effective sun defense covering your face, neck, and eyes. Forewarned is forearmed! The Sun's UV radiation can be almost doubled in intensity by snow reflection.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
How cold is December?
What is the average humidity in December?
How much does it rain in December?
When does it start to snow?
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?
What is the month with the least sunshine in Hyannis Port?
How many hours of sunshine does Hyannis Port have in December?
When is the lowest UV index?
What is the UV index reading in December?
Average temperature in December
Hyannis Port, MA
- Average high temperature in December: 43.7°F
The warmest month (with the highest average high temperature) is August (72.5°F).
The month with the lowest average high temperature is January (38.3°F).
- Average low temperature in December: 36.5°F
The month with the highest average low temperature is August (68.2°F).
The coldest month (with the lowest average low temperature) is January (30.4°F).
Average pressure in December
Hyannis Port, MA
- Average pressure in December: 30.03"Hg
The month with the highest atmospheric pressure is November (30.06"Hg).
The month with the lowest atmospheric pressure is June (29.93"Hg).
Average wind speed in December
Hyannis Port, MA
- Average wind speed in December: 16.1mph
The windiest month (with the highest average wind speed) is January (16.5mph).
The calmest month (with the lowest average wind speed) is August (10.6mph).
Average humidity in December
Hyannis Port, MA
- Average humidity in December: 75%
The month with the highest relative humidity is July (84%).
The month with the lowest relative humidity is November (74%).
Average rainfall in December
Hyannis Port, MA
- Average rainfall in December: 3.62"
The wettest month (with the highest rainfall) is October (3.7").
The driest month (with the least rainfall) is August (1.73").
Average rainfall days in December
Hyannis Port, MA
- Average rainfall days in December: 14.2 days
The month with the highest number of rainy days is April (15.8 days).
The month with the least rainy days is February (10.3 days).
Average snowfall in December
Hyannis Port, MA
- Average snowfall in December: 0.87"
The month with the highest snowfall is March (1.93").
The months with the least snowfall are May, June, July, August, September, October and November (0").
Average snowfall days in December
Hyannis Port, MA
- Average snowfall days in December: 4.4 days
The month with the highest number of snowfall days is February (7.1 days).
The months with the least snowfall days are May, June, July, August, September and October (0 days).
Average daylight in December /
Average sunshine in December
Hyannis Port, MA
- 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 4min
The month with the most sunshine is August (Average sunshine: 10h and 48min).
The month with the least sunshine is December (Average sunshine: 4h and 36min).
Average sunshine days in December
Hyannis Port, MA
- Average sunshine days in December: 12.6 days
The month with the most sunshine days is August (17.7 days).
The month with the least sunshine days is February (11.4 days).
Average UV index in December
Hyannis Port, MA
- Average UV index in December: 2
The months with the highest UV index are 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
Hyannis Port, MA
- Average cloud cover in December: 50
The months with the most cloud cover are February and December (Cloud cover 50).
The month with the least cloud cover is August (Cloud cover 27).
Average visibility in December
Hyannis Port, MA
- 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).
Hyannis Port, Massachusetts, USA
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