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

Weather in December

The first month of the winter, December, is also a subzero cold month in Juneau, Alaska, with average temperature ranging between min 19°F (-7.2°C) and max 25.7°F (-3.5°C).

Temperature

January and December, with an average high-temperature of 25.7°F (-3.5°C), are the coldest months.

Humidity

The average relative humidity in Juneau, Alaska, is 90%.

Rainfall

In Juneau, during December, the rain falls for 5.8 days and regularly aggregates up to 8.98" (228mm) of precipitation. Throughout the year, in Juneau, there are 172.4 rainfall days, and 85.87" (2181mm) of precipitation is accumulated.

Snowfall

January through May, October through December are months with snowfall in Juneau, Alaska. The month with the most snowfall is December when snow falls for 21.8 days and typically aggregates up to 62.8" (1595mm) of snow.

Ocean temperature

In Juneau, in December, the average water 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 in Juneau.

Sunshine

In Juneau, the average sunshine is 2.9h.

UV index

Months with the lowest UV index are January, April, October through December, with an average maximum UV index of 1. A UV Index reading of 2, and below, represents a low health risk from the exposure to the Sun's UV rays for ordinary individuals.
Note: The daily maximum UV index of 1 interpret into the following advice:
People with sensitive skin, children, and babies should always be protected from prolonged 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.
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FAQ

What is the coldest month in Juneau?

January and December, with an average high-temperature of 25.7°F (-3.5°C), are the coldest months.

What is the temperature in December in Juneau?

The average high-temperature, in December, in Juneau, is 25.7°F (-3.5°C), while the average low-temperature is 19°F (-7.2°C).

What is the average humidity in December in Juneau?

The average relative humidity in December in Juneau, Alaska, is 90%.

How much does it rain in Juneau in December?

In Juneau, Alaska, in December, it is raining for 5.8 days, with typically 8.98" (228mm) of accumulated precipitation.

How many days does it snow in December in Juneau?

In Juneau, in December, snow falls for 21.8 days, with typically accumulated 62.8" (1595mm) of snow.

What is the snowiest month in Juneau?

December is the month with the most snowfall in Juneau, Alaska. Snow falls for 21.8 days and accumulates 62.8" (1595mm) of snow.

How cold is the water in December in Juneau?

In December, the average ocean temperature is 43.3°F (6.3°C). At temperatures below 50°F (10°C), swimming in a suitably protected swimsuit is feasible; otherwise, cold shock and loss of breathing control are imminent. Even a short swim, without thermal protection, at temperatures around 55.4°F (13°C) is not comfortable.

What is the month with the shortest days in Juneau?

The month with the shortest days 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.

How long on average sun shines in December in Juneau?

The average sunshine in December in Juneau, Alaska, is 2.9h.

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

Months with the lowest UV index in Juneau, Alaska, are January, April, October through December, with an average maximum UV index of 1.

How high is the UV index in December in Juneau?

In Juneau, Alaska, the average daily maximum UV index in December is 1. A UV Index value of 2, and less, symbolizes a minimal health vulnerability from unprotected exposure to the UV radiation.

Average temperature in December
Juneau, AK

Average temperature in December - Juneau, AK
  • Average high temperature in December: -3.5°C

The warmest month (with the highest average high temperature) is July (13.2°C).
Months with the lowest average high temperature are January and December (-3.5°C).

  • Average low temperature in December: -7.2°C

The month with the highest average low temperature is July (7.3°C).
The coldest month (with the lowest average low temperature) is February (-8.3°C).

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Average pressure in December
Juneau, AK

Average pressure in December - Juneau, AK
  • Average pressure in December: 1011.6mbar

The month with the highest atmospheric pressure is July (1016.8mbar).
The month with the lowest atmospheric pressure is November (1009.1mbar).

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Average wind speed in December
Juneau, AK

Average wind speed in December - Juneau, AK
  • Average wind speed in December: 10.5km/h

The windiest month (with the highest average wind speed) is January (11.1km/h).
The calmest month (with the lowest average wind speed) is June (5.9km/h).

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Average humidity in December
Juneau, AK

Average humidity in December - Juneau, AK
  • Average humidity in December: 90%

The month with the highest relative humidity is January (92%).
The month with the lowest relative humidity is May (86%).

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Average rainfall in December
Juneau, AK

Average rainfall in December - Juneau, AK
  • Average rainfall in December: 228mm

The wettest month (with the highest rainfall) is October (251mm).
The driest month (with the least rainfall) is May (105mm).

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Average rainfall days in December
Juneau, AK

Average rainfall days in December - Juneau, AK
  • Average rainfall days in December: 5.8 days

The month with the highest number of rainy days is September (21.9 days).
The month with the least rainy days is February (4.8 days).

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Average snowfall in December
Juneau, AK

Average snowfall in December - Juneau, AK
  • Average snowfall in December: 1595mm

The month with the highest snowfall is December (1595mm).
Months with the least snowfall are June, July, August and September (0mm).

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Average snowfall days in December
Juneau, AK

Average snowfall days in December - Juneau, AK
  • Average snowfall days in December: 21.8 days

The month with the highest number of snowfall days is January (21.9 days).
Months with the least snowfall days are June, July, August and September (0 days).

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Average sea temperature in December
Juneau, AK

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).

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Average daylight in December /
Average sunshine in December
Juneau, AK

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 the shortest days is December (Average daylight: 6.5h).

  • Average sunshine in December: 2.9h

The month with the most sunshine is June (Average sunshine: 6.4h).
The month with the least sunshine is November (Average sunshine: 2.6h).

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Average sunshine days in December
Juneau, AK

Average sunshine days in December - Juneau, AK
  • Average sunshine days in December: 7.6 days

The month with the most sunshine days is May (10 days).
The month with the least sunshine days is November (6.1 days).

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Average UV index in December
Juneau, AK

Average UV index in December - Juneau, AK
  • Average UV index in December: 1

Months with the highest UV index are May and July (UV index 3).
Months with the lowest UV index are January, April, October, November and December (UV index 1).

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Average cloud cover in December
Juneau, AK

Average cloud cover in December - Juneau, AK
  • Average cloud cover in December: 71

Months with the most cloud cover are January and November (Cloud cover 72).
The month with the least cloud cover is May (Cloud cover 61).

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Average visibility in December
Juneau, AK

Average visibility in December - Juneau, AK
  • Average visibility in December: 6km

Months with the highest visibility are February, March, May, June, July, August, September, October and November (7km).
Months with the lowest visibility are January, April and December (6km).

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