Juneau
Alaska, USA
Long-term weather forecast
Long-term weather forecast

December weather forecast and climate
Juneau, AK

Blooming fireweed in Juneau, Alaska, with snowy mountain peaks in the distance
Blooming fireweed in Juneau, Alaska, with snowy mountain peaks in the distance
The first month of the winter, December, is still a cold month in Juneau, Alaska, with average temperature ranging between min 25.5°F (-3.6°C) and max 34.2°F (1.2°C).

Temperature

In Juneau, the average high-temperature in December is relatively the same as in November - a still wintry 34.2°F (1.2°C). The average low-temperature, in Juneau, is 25.5°F (-3.6°C).

Humidity

In December, the average relative humidity in Juneau is 82.8%.

Rainfall

In December, the rain falls for 20.6 days. Throughout December, 5.8" (148.3mm) of precipitation is accumulated. Throughout the year, in Juneau, there are 229.8 rainfall days, and 62.3" (1581.6mm) of precipitation is accumulated.

Snowfall

January through April, October through December are months with snowfall. In December, in Juneau, it is snowing for 10 days. Throughout December, 15.6" (396.2mm) of snow is accumulated. Throughout the year, there are 43.1 snowfall days, and 86.7" (2202mm) of snow is accumulated.

Ocean temperature

In December, the average ocean temperature is 43.3°F (6.3°C).
Note: Swimming in 43.3°F (6.3°C) is considered dangerous. Unprotected immersion in temperatures below 50°F (10°C) causes quickly maximum intensity cold shock with hyperventilation.

Daylight

With an average of 6.5h of daylight, December has the shortest days of the year.

Sunshine

December has the least sunshine of the year, with an average of 1.3h of sunshine.

UV index

January, November and December, with an average maximum UV index of 0, are months with the lowest UV index in Juneau. A UV Index estimate of 2, and below, represents a low health risk from unsafe exposure to the UV radiation for ordinary individuals.
Note: The daily maximum UV index of 0 interpret into the following advice:
Most people can stay in the Sun for up to 1 hour without burning, apart from children that always must be protected from sun exposure. The Sun's most intense and consequently most harmful UV radiation during midday hours should be decreased by minimizing exposure and seeking shade. A wide-brim hat offers excellent sun protection for eyes, ears, face, and neck. Sunglasses with UVA and UVB protection significantly reduce eye damage from sun exposure. Tightly woven, loose-fitting clothes provide additional protection from the Sun. Caution! The reflection of snow can nearly double the intensity of the Sun's UV radiation.

What is the temperature in December in Juneau?

In Juneau, Alaska, in December, the average high-temperature is 34.2°F (1.2°C), and the average low-temperature is 25.5°F (-3.6°C).

What is the average humidity in December in Juneau?

In Juneau, the average relative humidity in December is 82.8%.

How many days does it rain in December in Juneau?

In Juneau, during December, the rain falls for 20.6 days and regularly aggregates up to 5.8" (148.3mm) of precipitation.

How many days does it snow in December in Juneau?

In Juneau, in December, during 10 snowfall days, 15.6" (396.2mm) of snow is typically accumulated.

How cold is the water in December in Juneau?

In Juneau, the average seawater temperature in December is 43.3°F (6.3°C). Swimming in 43.3°F (6.3°C) is considered dangerous. Unprotected immersion in temperatures below 50°F (10°C) causes quickly maximum intensity cold shock with hyperventilation.

What is the month with the shortest days in Juneau?

The month with the shortest days in Juneau is December, with an average of 6.5h of daylight.

What is the average length of the day in December in Juneau?

In Juneau, Alaska, the average length of the day in December is 6.5h.

What is the month with the least sunshine in Juneau?

With an average of 1.3h of sunshine, December has the least sunshine of the year in Juneau.

How many hours of sunshine does Juneau have in December?

In December, the average sunshine in Juneau, Alaska, is 1.3h.

What are the months with the lowest UV index in Juneau?

Months with the lowest UV index in Juneau are January, November and December, with an average maximum UV index of 0.

What is the UV index reading in December in Juneau?

The average daily maximum UV index in December in Juneau, Alaska, is 0. A UV Index reading of 2, and below, represents a low health threat from unprotected exposure to the UV radiation.
Average temperature in December - Juneau, AK
  • Average high temperature in December: 1.2°C

The warmest month (with the highest average high temperature) is July (17.7°C).
The month with the lowest average high temperature is January (0.4°C).

  • Average low temperature in December: -3.6°C

The month with the highest average low temperature is July (10°C).
The coldest month (with the lowest average low temperature) is January (-4.6°C).

Average humidity in December - Juneau, AK
  • Average humidity in December: 82.8%

The month with the highest relative humidity is September (87.9%).
The month with the lowest relative humidity is May (76.3%).

Average rainfall in December - Juneau, AK
  • Average rainfall in December: 148.3mm

The wettest month (with the highest rainfall) is September (219.5mm).
The driest month (with the lowest rainfall) is April (74.7mm).

Average rainfall days in December - Juneau, AK
  • Average rainfall days in December: 20.6 days

The month with the highest number of rainy days is October (23.9 days).
The month with the lowest number of rainy days is June (15.8 days).

Average snowfall in December - Juneau, AK
  • Average snowfall in December: 396.2mm

The month with the highest snowfall is January (703.6mm).
Months with the lowest snowfall are May, June, July, August and September (0mm).

Average snowfall days in December - Juneau, AK
  • Average snowfall days in December: 10 days

The month with the highest number of snowfall days is January (10.6 days).
Months with the lowest number of snowfall days are May, June, July, August and September (0 days).

Average sea temperature in December - Juneau, AK
  • Average sea temperature in December: 6.3°C

The best month for swimming (with the highest average sea temperature) is August (11.9°C).
The coldest month (with the lowest average sea temperature) is March (4.7°C).

Average daylight in December / Average sunshine in December - Juneau, AK
  • Average daylight in December: 6.5h

The month with the longest days is June (Average daylight: 18.2h).
The month with shortest days is December (Average daylight: 6.5h).

  • Average sunshine in December: 1.3h

The month with most sunshine is May (Average sunshine: 7.5h).
The month with least sunshine is December (Average sunshine: 1.3h).

Average UV index in December - Juneau, AK
  • Average UV index in December: 0

Months with the highest UV index are June and July (UV index 5).
Months with the lowest UV index are January, November and December (UV index 0).