December weather forecastBoothbay Harbor, ME
December
Weather in December
December, the first month of the winter in Boothbay Harbor, is also an icy month, with an average temperature varying between 25.3°F (-3.7°C) and 35.2°F (1.8°C).Temperature
Transition from November to December is accompanied by a temperature drop, with average high-temperatures decreasing from a frosty 45.5°F (7.5°C) to a cold 35.2°F (1.8°C). In December, Boothbay Harbor encounters an average low-temperature of 25.3°F (-3.7°C) during the night.Humidity
In December, the average relative humidity in Boothbay Harbor is 78%.Rainfall
December is the month with the most rainfall. Rain falls for 10.8 days and accumulates 3.5" (89mm) of precipitation.Snowfall
January through May, November and December are months with snowfall. In Boothbay Harbor, in December, during 7 snowfall days, 3.39" (86mm) of snow is typically accumulated. Throughout the year, there are 40 snowfall days, and 20.08" (510mm) of snow is accumulated.Ocean temperature
In Boothbay Harbor, the average seawater temperature in December is 45.3°F (7.4°C).Note: To swim in 45.3°F (7.4°C) at less than 50°F (10°C), ensure you're well-protected. Without it, be prepared for a sudden jolt of cold and breathing issues. Remember, even 55.4°F (13°C) is not welcoming.
Daylight
The month with the shortest days is December, with an average of 9h and 0min of daylight.On the first day of the month, sunrise is at 6:53 am and sunset at 4:02 pm. On the last day of December, sunrise is at 7:12 am and sunset at 4:11 pm EST.
Sunshine
The months with the least sunshine are February and December, with an average of 4.6h of 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 value of 2, and less, symbolizes a minimal health hazard from unprotected exposure to Sun's UV rays for the average person.Note: The UV index of 2 during December leads to these advisories:
Extended sun exposure is not an issue for the majority. Children, infants, and fair-skinned individuals always need to be protected. When the Sun is at its strongest around midday, find shade and limit exposure. Counter UV radiation's ill effects with clothing designed for sun safety and UV-resistant eyewear. Be attentive! The reflective property of snow can nearly double the Sun's UV radiation.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in December
Boothbay Harbor, ME
- Average high temperature in December: 35.2°F
The warmest months (with the highest average high temperature) are July and August (74.1°F).
The month with the lowest average high temperature is January (29.7°F).
- Average low temperature in December: 25.3°F
The month with the highest average low temperature is July (59.5°F).
The coldest month (with the lowest average low temperature) is January (18°F).
Average pressure in December
Boothbay Harbor, ME
- Average pressure in December: 30.01"Hg
The months with the highest atmospheric pressure are September and November (30.04"Hg).
The month with the lowest atmospheric pressure is June (29.91"Hg).
Average wind speed in December
Boothbay Harbor, ME
- Average wind speed in December: 10mph
The windiest months (with the highest average wind speed) are January and March (10.6mph).
The calmest month (with the lowest average wind speed) is August (6.5mph).
Average humidity in December
Boothbay Harbor, ME
- Average humidity in December: 78%
The months with the highest relative humidity are June and July (82%).
The month with the lowest relative humidity is November (76%).
Average rainfall in December
Boothbay Harbor, ME
- Average rainfall in December: 3.5"
The wettest month (with the highest rainfall) is December (3.5").
The driest month (with the least rainfall) is September (1.5").
Average rainfall days in December
Boothbay Harbor, ME
- Average rainfall days in December: 10.8 days
The month with the highest number of rainy days is April (15.1 days).
The month with the least rainy days is January (6.6 days).
Average snowfall in December
Boothbay Harbor, ME
- Average snowfall in December: 3.39"
The month with the highest snowfall is January (5.28").
The months with the least snowfall are June, July, August, September and October (0").
Average snowfall days in December
Boothbay Harbor, ME
- Average snowfall days in December: 7 days
The month with the highest number of snowfall days is February (9.5 days).
The months with the least snowfall days are June, July, August and September (0 days).
Average sea temperature in December
Boothbay Harbor, ME
- Average sea temperature in December: 45.4°F
The best month for swimming (with the highest average sea temperature) is August (62.2°F).
The coldest month (with the lowest average sea temperature) is March (37.9°F).
Average daylight in December /
Average sunshine in December
Boothbay Harbor, ME
- Average daylight in December: 9h and 0min
The month with the longest days is June (Average daylight: 15h and 24min).
The month with the shortest days is December (Average daylight: 9h and 0min).
- Average sunshine in December: 4h and 36min
The month with the most sunshine is August (Average sunshine: 10h and 18min).
The months with the least sunshine are February and December (Average sunshine: 4h and 36min).
Average sunshine days in December
Boothbay Harbor, ME
- Average sunshine days in December: 14.5 days
The month with the most sunshine days is September (17.5 days).
The month with the least sunshine days is April (11.7 days).
Average UV index in December
Boothbay Harbor, ME
- Average UV index in December: 2
The month with the highest UV index is July (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
Boothbay Harbor, ME
- Average cloud cover in December: 51
The months with the most cloud cover are February and March (Cloud cover 52).
The month with the least cloud cover is August (Cloud cover 33).
Average visibility in December
Boothbay Harbor, ME
- Average visibility in December: 6mi
The months with the highest visibility are January, February, March, April, May, June, August, September, October, November and December (6mi).
The month with the lowest visibility is July (5mi).





