December weather forecastCastine, ME
December
Weather in December
December, the first month of the winter in Castine, is also an icy month, with an average temperature fluctuating between 34.2°F (1.2°C) and 24.1°F (-4.4°C).Temperature
Castine in December experiences a subtle temperature decline, with average high-temperatures reducing from a frosty 44.1°F (6.7°C) in November to a wintry 34.2°F (1.2°C). Castine experiences an average low-temperature reading of 24.1°F (-4.4°C) throughout December.Humidity
In Castine, the average relative humidity in December is 79%.Rainfall
December is the month with the most rainfall. Rain falls for 10.1 days and accumulates 2.72" (69mm) of precipitation.Snowfall
Months with snowfall are January through May, October through December. In Castine, during December, snow falls for 8.9 days and regularly aggregates up to 2.28" (58mm) of snow. Throughout the year, there are 44.3 snowfall days, and 16.81" (427mm) of snow is accumulated.Ocean temperature
In Castine, the average seawater temperature in December is 45.5°F (7.5°C).Note: Dipping into 45.5°F (7.5°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
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 6:51 am and sunset at 3:57 pm. On the last day of the month, sunrise is at 7:11 am and sunset at 4:05 pm EST.
Sunshine
In December, the average sunshine in Castine 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 estimate 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, 2 during December, leads to the following recommendations:
Babies, children, and those with sensitive skin should always avoid extended periods in the sun. Limiting sun exposure during midday hours helps in reducing the harmful effects of UV radiation. Arm yourself against UV rays' harm with protective apparel and UV-filtering shades. Bear in mind! The Sun's UV radiation can nearly double in intensity due to the reflective quality of snow.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in December
Castine, ME
- Average high temperature in December: 34.2°F
The warmest months (with the highest average high temperature) are July and August (73.9°F).
The month with the lowest average high temperature is January (28.4°F).
- Average low temperature in December: 24.1°F
The month with the highest average low temperature is July (57.7°F).
The coldest month (with the lowest average low temperature) is January (16.2°F).
Average pressure in December
Castine, ME
- Average pressure in December: 30"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
Castine, ME
- Average wind speed in December: 9.6mph
The windiest month (with the highest average wind speed) is March (10.1mph).
The calmest months (with the lowest average wind speed) are July and August (6mph).
Average humidity in December
Castine, ME
- Average humidity in December: 79%
The months with the highest relative humidity are February and July (83%).
The month with the lowest relative humidity is November (77%).
Average rainfall in December
Castine, ME
- Average rainfall in December: 2.72"
The wettest month (with the highest rainfall) is December (2.72").
The driest months (with the least rainfall) are July and September (1.46").
Average rainfall days in December
Castine, ME
- 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 February (7.1 days).
Average snowfall in December
Castine, ME
- Average snowfall in December: 2.28"
The month with the highest snowfall is January (4.57").
The months with the least snowfall are June, July, August and September (0").
Average snowfall days in December
Castine, ME
- Average snowfall days in December: 8.9 days
The month with the highest number of snowfall days is January (10.1 days).
The months with the least snowfall days are June, July, August and September (0 days).
Average sea temperature in December
Castine, ME
- Average sea temperature in December: 45.6°F
The best month for swimming (with the highest average sea temperature) is August (58.6°F).
The coldest month (with the lowest average sea temperature) is March (38.2°F).
Average daylight in December /
Average sunshine in December
Castine, 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: 9h and 54min).
The month with the least sunshine is February (Average sunshine: 4h and 18min).
Average sunshine days in December
Castine, ME
- Average sunshine days in December: 14.5 days
The month with the most sunshine days is September (17.9 days).
The month with the least sunshine days is April (11.7 days).
Average UV index in December
Castine, 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
Castine, ME
- Average cloud cover in December: 52
The month with the most cloud cover is March (Cloud cover 55).
The months with the least cloud cover are August and September (Cloud cover 37).
Average visibility in December
Castine, ME
- Average visibility in December: 6mi
The months with the highest visibility are January, February, March, April, October, November and December (6mi).
The months with the lowest visibility are May, June, July, August and September (5mi).





