December weather forecastSumner, ME
December
Weather in December
The first month of the winter, December, is still a freezing cold month in Sumner, Maine, with an average temperature fluctuating between 29.1°F (-1.6°C) and 19°F (-7.2°C).Temperature
The commencement of December involves a temperature shift, with the average high-temperature dropping from a wintry 40.5°F (4.7°C) in November to a freezing cold 29.1°F (-1.6°C). Throughout December nights, Sumner registers an average low-temperature of 19°F (-7.2°C).Humidity
In Sumner, Maine, the average relative humidity in December is 82%.Rainfall
In Sumner, in December, it is raining for 9.5 days, with typically 2.52" (64mm) of accumulated precipitation. Throughout the year, there are 146.3 rainfall days, and 28.31" (719mm) of precipitation is accumulated.Snowfall
Months with snowfall are January through May, October through December. In Sumner, Maine, in December, snow falls for 12.5 days, with typically accumulated 7.44" (189mm) of snow. Throughout the year, there are 69.3 snowfall days, and 48.15" (1223mm) of snow is accumulated.Daylight
The month with the shortest days is December, with an average of 8h and 54min of daylight.On the first day of December, sunrise is at 6:58 am and sunset at 4:03 pm. On the last day of the month, sunrise is at 7:17 am and sunset at 4:12 pm EST.
Sunshine
In December, the average sunshine is 4.3h.UV index
The months with the lowest UV index are February and December, with an average maximum UV index of 1. A UV Index reading of 2, and below, represents a minimal health vulnerability from exposure to the Sun's UV radiation for ordinary individuals.Note: A daily high UV index of 1 in December leads to these guidelines:
Babies, children, and individuals with sensitive skin should always have protection against extended sun exposure. Direct exposure to the Sun's intense radiation around midday should be avoided for health reasons. Stay sun-safe with clothing that is both closely woven and worn loosely. Caution! The reflection of snow can nearly 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
Sumner, ME
- Average high temperature in December: 29.1°F
The warmest month (with the highest average high temperature) is July (76.8°F).
The month with the lowest average high temperature is January (23.7°F).
- Average low temperature in December: 19°F
The month with the highest average low temperature is July (55.4°F).
The coldest month (with the lowest average low temperature) is January (10°F).
Average pressure in December
Sumner, ME
- Average pressure in December: 30.02"Hg
The month with the highest atmospheric pressure is November (30.05"Hg).
The month with the lowest atmospheric pressure is June (29.91"Hg).
Average wind speed in December
Sumner, ME
- Average wind speed in December: 6.2mph
The windiest month (with the highest average wind speed) is March (6.8mph).
The calmest month (with the lowest average wind speed) is August (4.5mph).
Average humidity in December
Sumner, ME
- Average humidity in December: 82%
The months with the highest relative humidity are January, February and March (86%).
The months with the lowest relative humidity are May and November (76%).
Average rainfall in December
Sumner, ME
- Average rainfall in December: 2.52"
The wettest month (with the highest rainfall) is October (3.31").
The driest month (with the least rainfall) is July (1.85").
Average rainfall days in December
Sumner, ME
- Average rainfall days in December: 9.5 days
The month with the highest number of rainy days is June (15.5 days).
The month with the least rainy days is February (8.2 days).
Average snowfall in December
Sumner, ME
- Average snowfall in December: 7.44"
The month with the highest snowfall is February (12.28").
The months with the least snowfall are June, July, August and September (0").
Average snowfall days in December
Sumner, ME
- Average snowfall days in December: 12.5 days
The month with the highest number of snowfall days is February (15.3 days).
The months with the least snowfall days are June, July, August and September (0 days).
Average daylight in December /
Average sunshine in December
Sumner, 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 18min
The month with the most sunshine is August (Average sunshine: 9h and 42min).
The month with the least sunshine is February (Average sunshine: 4h and 0min).
Average sunshine days in December
Sumner, ME
- Average sunshine days in December: 13.8 days
The month with the most sunshine days is September (16.7 days).
The months with the least sunshine days are February and April (11.3 days).
Average UV index in December
Sumner, ME
- Average UV index in December: 1
The months with the highest UV index are June, July and August (UV index 5).
The months with the lowest UV index are February and December (UV index 1).
Average cloud cover in December
Sumner, ME
- Average cloud cover in December: 55
The month with the most cloud cover is February (Cloud cover 57).
The month with the least cloud cover is September (Cloud cover 40).
Average visibility in December
Sumner, ME
- Average visibility in December: 5mi
The months with the highest visibility are May, June, October, November and December (5mi).
The months with the lowest visibility are January, February, March, April, July, August and September (4mi).





