December weather forecastRockport, MA
December
Weather in December
The first month of the winter, December, is still a cold month in Rockport, Massachusetts, with an average temperature varying between 32.5°F (0.3°C) and 40.5°F (4.7°C).Temperature
A modest decline in the average high-temperature is seen during December, decreasing from a frosty 48.7°F (9.3°C) in November to an icy 40.5°F (4.7°C). Rockport in December experiences a minor decline in temperature, with an average low of 32.5°F (0.3°C) at night.Humidity
In Rockport, the average relative humidity in December is 75%.Rainfall
The month with the most rainfall is December, when the rain falls for 11.4 days and typically aggregates up to 3.23" (82mm) of precipitation.Snowfall
Months with snowfall are January through April, November and December. In December, it is snowing for 4.9 days. Throughout December, 2.01" (51mm) of snow is accumulated. Throughout the year, there are 27.4 snowfall days, and 9.17" (233mm) of snow is accumulated.Ocean temperature
In Rockport, Massachusetts, the average seawater temperature in December is 46°F (7.8°C).Note: It is risky to swim in 46°F (7.8°C). Temperatures beneath 50°F (10°C) induce rapid cold shock and hyperventilation.
Daylight
The month with the shortest days in Rockport is December, with an average of 9h and 6min of daylight.On the first day of the month, sunrise is at 6:53 am and sunset at 4:09 pm. On the last day of December, sunrise is at 7:12 am and sunset at 4:19 pm EST.
Sunshine
February and December, with an average of 4.8h of sunshine, are months with the least sunshine.UV index
The months with the lowest UV index are January through March, November and December, with an average maximum UV index of 2. A UV Index reading of 2, and below, represents a minimal health vulnerability from unprotected exposure to Sun's UV rays for average individuals.Note: The maximum UV index of 2 during December translates into these guidelines:
While most people are not greatly affected by extended sun exposure, those with fair skin, babies, and children must always have protection. The intensity of the Sun's UV radiation during midday suggests reducing time spent outdoors. Sun protection is enhanced with clothing that boasts a tight weave yet offers a loose fit. Pay attention! The reflection of snow can enhance the Sun's UV radiation almost double.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in December
Rockport, MA
- Average high temperature in December: 40.5°F
The warmest month (with the highest average high temperature) is August (73°F).
The month with the lowest average high temperature is January (34.9°F).
- Average low temperature in December: 32.5°F
The month with the highest average low temperature is August (65.5°F).
The coldest month (with the lowest average low temperature) is January (26.1°F).
Average pressure in December
Rockport, 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 (29.92"Hg).
Average wind speed in December
Rockport, MA
- Average wind speed in December: 14.4mph
The windiest month (with the highest average wind speed) is January (15.2mph).
The calmest months (with the lowest average wind speed) are July and August (8.9mph).
Average humidity in December
Rockport, MA
- Average humidity in December: 75%
The month with the highest relative humidity is June (81%).
The month with the lowest relative humidity is November (73%).
Average rainfall in December
Rockport, MA
- Average rainfall in December: 3.23"
The wettest month (with the highest rainfall) is December (3.23").
The driest month (with the least rainfall) is September (1.73").
Average rainfall days in December
Rockport, MA
- Average rainfall days in December: 11.4 days
The month with the highest number of rainy days is May (16.3 days).
The month with the least rainy days is February (8.2 days).
Average snowfall in December
Rockport, MA
- Average snowfall in December: 2.01"
The month with the highest snowfall is February (2.6").
The months with the least snowfall are May, June, July, August, September and October (0").
Average snowfall days in December
Rockport, MA
- Average snowfall days in December: 4.9 days
The month with the highest number of snowfall days is January (7.8 days).
The months with the least snowfall days are June, July, August, September and October (0 days).
Average sea temperature in December
Rockport, MA
- Average sea temperature in December: 45.9°F
The best month for swimming (with the highest average sea temperature) is August (66.4°F).
The coldest month (with the lowest average sea temperature) is March (38.8°F).
Average daylight in December /
Average sunshine in December
Rockport, MA
- Average daylight in December: 9h and 6min
The month with the longest days is June (Average daylight: 15h and 18min).
The month with the shortest days is December (Average daylight: 9h and 6min).
- Average sunshine in December: 4h and 48min
The month with the most sunshine is August (Average sunshine: 10h and 48min).
The months with the least sunshine are February and December (Average sunshine: 4h and 48min).
Average sunshine days in December
Rockport, MA
- Average sunshine days in December: 15.1 days
The months with the most sunshine days are September and November (16.7 days).
The month with the least sunshine days is February (13.1 days).
Average UV index in December
Rockport, 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
Rockport, MA
- Average cloud cover in December: 48
The month with the most cloud cover is March (Cloud cover 50).
The month with the least cloud cover is August (Cloud cover 27).
Average visibility in December
Rockport, 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).
