December weather forecastWinthrop, MA
December
Weather in December
The first month of the winter, December, is still a cold month in Winthrop, Massachusetts, with an average temperature ranging between min 29.7°F (-1.3°C) and max 39.9°F (4.4°C).Temperature
Winthrop's progression into December involves a drop in the average high-temperature, receding from a frosty 49.5°F (9.7°C) in November to an icy 39.9°F (4.4°C). Winthrop temperatures generally rest at a low of 29.7°F (-1.3°C) during the December nights.Humidity
In Winthrop, the average relative humidity in December is 76%.Rainfall
The months with the most rainfall are March, April and December, with an average 2.91" (74mm) of precipitation.Snowfall
Months with snowfall are January through May, October through December. In Winthrop, during December, snow falls for 5.2 days and regularly aggregates up to 2.83" (72mm) of snow. Throughout the year, there are 29.8 snowfall days, and 15.75" (400mm) of snow is accumulated.Ocean temperature
In Winthrop, the average seawater temperature in December is 46.2°F (7.9°C).Note: Dipping into 46.2°F (7.9°C) below 50°F (10°C) needs protective wear, or you'd face cold shock and breathing issues swiftly. Meanwhile, a slight swim around 55.4°F (13°C) feels cold to the bone.
Daylight
With an average of 9h and 6min of daylight, December has the shortest days of the year.On the first day of December, sunrise is at 6:54 am and sunset at 4:12 pm. On the last day of the month, sunrise is at 7:13 am and sunset at 4:21 pm EST.
Sunshine
The average sunshine in December is 4.7h.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 reading of 2, and below, represents a minimal health hazard from exposure to the Sun's UV radiation for ordinary individuals.Note: A daily high UV index of 2 in December leads to these guidelines:
Unlike children, who always need sun protection, most individuals can remain in the sun for up to an hour without getting burnt. The Sun's most harmful UV rays are emitted around midday; avoid staying outdoors for long during this time. Select sunglasses that boast both UVA and UVB protection to limit the adverse effects of the sun on the eyes. Consider this! The reflection from snow can almost double the intensity of the Sun's UV radiation.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in December
Winthrop, MA
- Average high temperature in December: 39.9°F
The warmest month (with the highest average high temperature) is July (81.7°F).
The month with the lowest average high temperature is January (34.2°F).
- Average low temperature in December: 29.7°F
The month with the highest average low temperature is July (64.9°F).
The coldest month (with the lowest average low temperature) is January (22.6°F).
Average pressure in December
Winthrop, 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
Winthrop, MA
- Average wind speed in December: 9.4mph
The windiest month (with the highest average wind speed) is January (9.9mph).
The calmest month (with the lowest average wind speed) is August (6.2mph).
Average humidity in December
Winthrop, MA
- Average humidity in December: 76%
The month with the highest relative humidity is February (77%).
The month with the lowest relative humidity is April (69%).
Average rainfall in December
Winthrop, MA
- Average rainfall in December: 2.91"
The wettest months (with the highest rainfall) are March, April and December (2.91").
The driest month (with the least rainfall) is September (1.26").
Average rainfall days in December
Winthrop, MA
- Average rainfall days in December: 10.1 days
The month with the highest number of rainy days is May (15.3 days).
The month with the least rainy days is January (7.9 days).
Average snowfall in December
Winthrop, MA
- Average snowfall in December: 2.83"
The month with the highest snowfall is February (4.72").
The months with the least snowfall are June, July, August and September (0").
Average snowfall days in December
Winthrop, MA
- Average snowfall days in December: 5.2 days
The months with the highest number of snowfall days are January and February (7.6 days).
The months with the least snowfall days are June, July, August and September (0 days).
Average sea temperature in December
Winthrop, MA
- Average sea temperature in December: 46.3°F
The best month for swimming (with the highest average sea temperature) is August (67.6°F).
The coldest month (with the lowest average sea temperature) is March (38.8°F).
Average daylight in December /
Average sunshine in December
Winthrop, MA
- Average daylight in December: 9h and 6min
The month with the longest days is June (Average daylight: 15h and 12min).
The month with the shortest days is December (Average daylight: 9h and 6min).
- Average sunshine in December: 4h and 42min
The month with the most sunshine is August (Average sunshine: 10h and 30min).
The month with the least sunshine is February (Average sunshine: 4h and 36min).
Average sunshine days in December
Winthrop, MA
- Average sunshine days in December: 16.5 days
The month with the most sunshine days is September (17.7 days).
The month with the least sunshine days is April (13 days).
Average UV index in December
Winthrop, MA
- 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
Winthrop, MA
- Average cloud cover in December: 48
The month with the most cloud cover is March (Cloud cover 51).
The month with the least cloud cover is August (Cloud cover 32).
Average visibility in December
Winthrop, 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).





