December weather forecastSouthwest Harbor, ME
December
Weather in December
The first month of the winter, December, is also a wintry month in Southwest Harbor, Maine, with an average temperature varying between 25.7°F (-3.5°C) and 35.1°F (1.7°C).Temperature
In Southwest Harbor, the average high-temperature in December drops from a chilly 44.8°F (7.1°C) in November to a cold 35.1°F (1.7°C). In December, Southwest Harbor experiences an average nighttime temperature of 25.7°F (-3.5°C).Humidity
In Southwest Harbor, the average relative humidity in December is 78%.Rainfall
The month with the most rainfall in Southwest Harbor is December, when the rain falls for 11.5 days and typically aggregates up to 3.94" (100mm) of precipitation.Snowfall
Months with snowfall in Southwest Harbor are January through May, October through December. In December, it is snowing for 7.9 days. Throughout December, 3.78" (96mm) of snow is accumulated. Throughout the year, there are 48.1 snowfall days, and 23.82" (605mm) of snow is accumulated.Daylight
December has the shortest days of the year, with an average of 8h and 54min of daylight.On the first day of December, sunrise is at 6:49 am and sunset at 3:55 pm. On the last day of the month, sunrise is at 7:08 am and sunset at 4:04 pm EST.
Sunshine
In December, the average sunshine is 4.4h.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 value of 2, and less, symbolizes a minimal health hazard from exposure to the Sun's UV rays for the ordinary person.Note: In December, the maximum UV index of 2 suggests these recommendations:
While most can endure approximately an hour in the sun without burning, children always require protection from sunlight. The Sun's harshest UV rays are around midday; it's wise to seek shade and limit time outdoors. Sunglasses that guard against UVA and UVB rays are pivotal in minimizing sun-induced ocular damage. Be cautious! The UV radiation from the Sun can be magnified almost twofold by snow reflection.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in December
Southwest Harbor, ME
- Average high temperature in December: 35.1°F
The warmest month (with the highest average high temperature) is August (73.4°F).
The month with the lowest average high temperature is January (29.7°F).
- Average low temperature in December: 25.7°F
The month with the highest average low temperature is July (58.1°F).
The coldest month (with the lowest average low temperature) is January (18.5°F).
Average pressure in December
Southwest Harbor, ME
- Average pressure in December: 29.99"Hg
The month with the highest atmospheric pressure is September (30.04"Hg).
The month with the lowest atmospheric pressure is June (29.91"Hg).
Average wind speed in December
Southwest Harbor, ME
- Average wind speed in December: 10.1mph
The windiest month (with the highest average wind speed) is January (10.4mph).
The calmest months (with the lowest average wind speed) are July and August (6.3mph).
Average humidity in December
Southwest Harbor, ME
- Average humidity in December: 78%
The month with the highest relative humidity is February (83%).
The month with the lowest relative humidity is November (76%).
Average rainfall in December
Southwest Harbor, ME
- Average rainfall in December: 3.94"
The wettest month (with the highest rainfall) is December (3.94").
The driest month (with the least rainfall) is July (1.57").
Average rainfall days in December
Southwest Harbor, ME
- Average rainfall days in December: 11.5 days
The month with the highest number of rainy days is April (15.5 days).
The month with the least rainy days is February (7.5 days).
Average snowfall in December
Southwest Harbor, ME
- Average snowfall in December: 3.78"
The month with the highest snowfall is February (5.75").
The months with the least snowfall are June, July, August and September (0").
Average snowfall days in December
Southwest Harbor, ME
- Average snowfall days in December: 7.9 days
The month with the highest number of snowfall days is January (11.8 days).
The months with the least snowfall days are June, July, August and September (0 days).
Average daylight in December /
Average sunshine in December
Southwest Harbor, ME
- Average daylight in December: 8h and 54min
The month with the longest days is June (Average daylight: 15h and 30min).
The month with the shortest days is December (Average daylight: 8h and 54min).
- Average sunshine in December: 4h and 24min
The month with the most sunshine is August (Average sunshine: 10h and 6min).
The month with the least sunshine is February (Average sunshine: 4h and 6min).
Average sunshine days in December
Southwest Harbor, ME
- Average sunshine days in December: 14.1 days
The month with the most sunshine days is August (18.7 days).
The month with the least sunshine days is April (11.2 days).
Average UV index in December
Southwest Harbor, ME
- Average UV index in December: 2
The months with the highest UV index are June, July and August (UV index 5).
The months with the lowest UV index are January, February, March, November and December (UV index 2).
Average cloud cover in December
Southwest Harbor, ME
- Average cloud cover in December: 53
The month with the most cloud cover is February (Cloud cover 56).
The months with the least cloud cover are August and September (Cloud cover 35).
Average visibility in December
Southwest Harbor, ME
- Average visibility in December: 6mi
The months with the highest visibility are January, February, March, April, May, June, September, October, November and December (6mi).
The months with the lowest visibility are July and August (5mi).





