December weather forecast
Calais, ME

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Weather in December

The arrival of December in Calais marks the return of the winter, bringing along with it cold temperatures and snowy landscapes. Average temperatures range between 21.9°F (-5.6°C) and 32.7°F (0.4°C), a clear indication of the upcoming frigid weather. As daylight hours shrink to the shortest of the year, the city endures more nights. The month also witnesses the first substantial snowfall, setting a picturesque winter terrain. December’s weather, dominated by cold winds and snow, often transforms Calais into an idyllic winter postcard.

Temperature

December's onset brings a slight change in high-temperatures, falling from a frosty 42.8°F (6°C) in November to an icy 32.7°F (0.4°C). December brings an average low-temperature of 21.9°F (-5.6°C) to Calais.

Humidity

In December, the average relative humidity is 83%.

Rainfall

December is the month with the most rainfall. Rain falls for 12.5 days and accumulates 3.7" (94mm) of precipitation.

Snowfall

January through May, October through December are months with snowfall in Calais. In December, it is snowing for 11.1 days. Throughout December, 5.24" (133mm) of snow is accumulated. In Calais, during the entire year, snow falls for 64.6 days and aggregates up to 30.47" (774mm) of snow.

Daylight

The month with the shortest days is December, with an average of 8h and 48min of daylight.
On the first day of December, sunrise is at 7:48 am and sunset at 4:48 pm. On the last day of the month, sunrise is at 8:07 am and sunset at 4:56 pm AST.

Sunshine

In Calais, the average sunshine in December is 4.1h.

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 reading of 2, and below, represents a minimal health hazard from exposure to the Sun's UV rays for the average person.
Note: In December, the UV index of 2 transforms into the following advice:
Most individuals face no major issues with lengthy exposure to the sun, but children, infants, and individuals with fair skin always require protection. The Sun's most intense and consequently most harmful UV radiation during midday hours should be decreased by minimizing exposure and seeking shade. Using UVA and UVB-protective sunglasses and sun-protective clothing is effective against UV radiation. Be careful! The Sun's UV radiation can nearly be doubled by the reflective quality of snow.
Updated: Jun 26, 2024
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate

Frequently asked questions

How cold is December?

December temperatures vary between a high-temperature of 32.7°F (0.4°C) and a low-temperature of 21.9°F (-5.6°C).

What is the average humidity in December?

The average relative humidity in December is 83%.

What is the rainiest month?

December is the month with the most rainfall in Calais, Maine. Rain falls for 12.5 days and accumulates 3.7" (94mm) of precipitation.

How many days does it rain in December?

In Calais, during December, the rain falls for 12.5 days and regularly aggregates up to 3.7" (94mm) of precipitation.

How many days does it snow in December?

In Calais, in December, snow falls for 11.1 days, with typically accumulated 5.24" (133mm) of snow.

What is the month with the shortest days?

The month with the shortest days is December, with an average of 8h and 48min of daylight.

How many hours of daylight does Calais have in December?

In December, the average day length is 8h and 49min.

What time are sunrise and sunset in December?

On the first day of December, sunrise is at 7:48 am and sunset at 4:48 pm. On the last day of the month, sunrise is at 8:07 am and sunset at 4:56 pm AST.

How many hours of sunshine does Calais have in December?

In December, the average sunshine duration is 4.1h.

When is the lowest UV index?

The months with the lowest UV index are January through March, November and December, with an average maximum UV index of 2.

What is the UV index intensity in December?

In Calais, the average daily maximum UV index in December is 2. A UV Index value of 2, and less, symbolizes a low health threat from unsafe exposure to Sun's UV rays.
Average humidity
Average rainfall days
Average snowfall days
Average daylight
Average sunshine
Average sunshine days
Average UV index
Average cloud cover
Average visibility

Average temperature in December
Calais, ME

Average temperature in December - Calais, ME
  • Average high temperature in December: 32.7°F

The warmest month (with the highest average high temperature) is July (74.8°F).
The month with the lowest average high temperature is January (26.6°F).

  • Average low temperature in December: 21.9°F

The month with the highest average low temperature is July (56.8°F).
The coldest month (with the lowest average low temperature) is January (13.8°F).

Average pressure in December
Calais, ME

Average pressure in December - Calais, ME
  • Average pressure in December: 29.98"Hg

The month with the highest atmospheric pressure is September (30.03"Hg).
The month with the lowest atmospheric pressure is June (29.91"Hg).

Average wind speed in December
Calais, ME

Average wind speed in December - Calais, ME
  • Average wind speed in December: 8.8mph

The windiest month (with the highest average wind speed) is March (9.3mph).
The calmest month (with the lowest average wind speed) is August (6.1mph).

Average humidity in December
Calais, ME

Average humidity in December - Calais, ME
  • Average humidity in December: 83%

The month with the highest relative humidity is February (87%).
The month with the lowest relative humidity is May (78%).

Average rainfall in December
Calais, ME

Average rainfall in December - Calais, ME
  • Average rainfall in December: 3.7"

The wettest month (with the highest rainfall) is December (3.7").
The driest month (with the least rainfall) is August (1.77").

Average rainfall days in December
Calais, ME

Average rainfall days in December - Calais, ME
  • Average rainfall days in December: 12.5 days

The month with the highest number of rainy days is April (17.2 days).
The month with the least rainy days is February (7.8 days).

Average snowfall in December
Calais, ME

Average snowfall in December - Calais, ME
  • Average snowfall in December: 5.24"

The month with the highest snowfall is January (7.44").
The months with the least snowfall are June, July, August and September (0").

Average snowfall days in December
Calais, ME

Average snowfall days in December - Calais, ME
  • Average snowfall days in December: 11.1 days

The month with the highest number of snowfall days is January (15.2 days).
The months with the least snowfall days are June, July, August and September (0 days).

Average daylight in December /
Average sunshine in December
Calais, ME

Average daylight in December / Average sunshine in December - Calais, ME
  • Average daylight in December: 8h and 5min

The month with the longest days is June (Average daylight: 15h and 36min).
The month with the shortest days is December (Average daylight: 8h and 48min).

  • Average sunshine in December: 4h and 1min

The month with the most sunshine is August (Average sunshine: 9h and 48min).
The month with the least sunshine is February (Average sunshine: 3h and 24min).

Average sunshine days in December
Calais, ME

Average sunshine days in December - Calais, ME
  • Average sunshine days in December: 12.5 days

The month with the most sunshine days is September (16.6 days).
The month with the least sunshine days is April (8.5 days).

Average UV index in December
Calais, ME

Average UV index in December - Calais, 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
Calais, ME

Average cloud cover in December - Calais, ME
  • Average cloud cover in December: 57

The month with the most cloud cover is February (Cloud cover 62).
The month with the least cloud cover is August (Cloud cover 38).

Average visibility in December
Calais, ME

Average visibility in December - Calais, ME
  • Average visibility in December: 6mi

The months with the highest visibility are May, October, November and December (6mi).
The months with the lowest visibility are January, February, March, April, June, July, August and September (5mi).

Calais, Maine, USA

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