December weather forecast
Mukilteo, WA

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White buildings in neat, green fields near the iconic Mukilteo Lighthouse, Washington
White buildings in neat, green fields near the iconic Mukilteo Lighthouse, Washington

Weather in December

December, the first month of the winter in Mukilteo, is also an icy month, with an average temperature varying between 42.6°F (5.9°C) and 35.4°F (1.9°C).

Temperature

In Mukilteo, the month of December is known for its lowest average temperatures, reaching a high of 42.6°F (5.9°C) and a low of 35.4°F (1.9°C).

Humidity

The months with the highest humidity are February and December, with an average relative humidity of 84%.

Rainfall

The month with the most rainfall is December, when the rain falls for 18.1 days and typically aggregates up to 3.54" (90mm) of precipitation.

Snowfall

January through April, November and December are months with snowfall. In Mukilteo, in December, snow falls for 3.2 days, with typically accumulated 1.18" (30mm) of snow. Throughout the year, there are 16.3 snowfall days, and 10.08" (256mm) of snow is accumulated.

Ocean temperature

In December, the average ocean temperature is 46.6°F (8.1°C).
Note: Swimming in 46.6°F (8.1°C) poses a severe threat. Even short exposure to 55.4°F (13°C) is chilling, and going below 50°F (10°C) can cause breathing irregularities and intense cold shock, based on one's stamina.

Daylight

With an average of 8h and 30min of daylight, December has the shortest days of the year.
On the first day of December, sunrise is at 7:38 am and sunset at 4:18 pm. On the last day of the month, sunrise is at 7:58 am and sunset at 4:26 pm PST.

Sunshine

The average sunshine in December is 4.5h.

UV index

January, February, November and December, with an average maximum UV index of 2, are months with the lowest UV index. A UV Index of 2, and less, symbolizes a minimal health hazard from exposure to the Sun's UV radiation for average individuals.
Note: A maximum high daily UV index of 2 during December translates into the following directions:
While most people are not greatly affected by extended sun exposure, those with fair skin, babies, and children must always have protection. Midday is the peak time for the Sun's radiation; stay in the shade and protect yourself. Sun-related eye harm can be minimized with proper sunglasses offering UVA and UVB coverage. Take note! UV radiation from the Sun can double in intensity due to snow reflection.

Frequently asked questions

What are the coldest months?

December is the month that records the lowest temperatures, with averages ranging from a high of 42.6°F (5.9°C) to a low of 35.4°F (1.9°C).

How cold is it in December?

An average high-temperature, in December, in Mukilteo, is 42.6°F (5.9°C) and the average low-temperature is 35.4°F (1.9°C).

What is the most humid month?

February and December, with an average relative humidity of 84%, are most humid months.

What is the average humidity in December?

In December, the average relative humidity is 84%.

What is the rainiest month in Mukilteo?

December is the month with the most rainfall. Rain falls for 18.1 days and accumulates 3.54" (90mm) of precipitation.

How much does it rain in December?

In Mukilteo, during December, the rain falls for 18.1 days and regularly aggregates up to 3.54" (90mm) of precipitation.

How many days does it snow in December?

In Mukilteo, in December, during 3.2 snowfall days, 1.18" (30mm) of snow is typically accumulated.

What is the ocean temperature in December?

In Mukilteo, the average seawater temperature in December is 46.6°F (8.1°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?

With an average of 8h and 30min of daylight, December has the shortest days of the year.

How many hours of daylight does Mukilteo have in December?

In December, the average day length is 8h and 28min.

What time are sunrise and sunset in December?

In December, on the first day of the month, sunrise is at 7:38 am and sunset at 4:18 pm. On the last day of the month, sunrise is at 7:58 am and sunset at 4:26 pm PST.

How long on average sun shines in December?

In Mukilteo, the average sunshine duration in December is 4.5h.

What is the month with the lowest UV index?

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

What is the UV index reading in December?

In Mukilteo, the average daily maximum UV index in December is 2. A UV Index reading of 2, and below, represents a low health threat from exposure to the Sun's UV radiation.
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
Mukilteo, WA

Average temperature in December - Mukilteo, WA
  • Average high temperature in December: 42.6°F

The warmest month (with the highest average high temperature) is August (72.7°F).
The month with the lowest average high temperature is December (42.6°F).

  • Average low temperature in December: 35.4°F

The month with the highest average low temperature is August (54°F).
The coldest month (with the lowest average low temperature) is December (35.4°F).

Average pressure in December
Mukilteo, WA

Average pressure in December - Mukilteo, WA
  • Average pressure in December: 30.08"Hg

The month with the highest atmospheric pressure is January (30.09"Hg).
The months with the lowest atmospheric pressure are March, August and September (30.01"Hg).

Average wind speed in December
Mukilteo, WA

Average wind speed in December - Mukilteo, WA
  • Average wind speed in December: 5.7mph

The windiest month (with the highest average wind speed) is November (6.2mph).
The calmest month (with the lowest average wind speed) is August (3.6mph).

Average humidity in December
Mukilteo, WA

Average humidity in December - Mukilteo, WA
  • Average humidity in December: 84%

The months with the highest relative humidity are February and December (84%).
The month with the lowest relative humidity is July (72%).

Average rainfall in December
Mukilteo, WA

Average rainfall in December - Mukilteo, WA
  • Average rainfall in December: 3.54"

The wettest month (with the highest rainfall) is December (3.54").
The driest month (with the least rainfall) is July (0.43").

Average rainfall days in December
Mukilteo, WA

Average rainfall days in December - Mukilteo, WA
  • Average rainfall days in December: 18.1 days

The month with the highest number of rainy days is March (19.8 days).
The month with the least rainy days is August (6.3 days).

Average snowfall in December
Mukilteo, WA

Average snowfall in December - Mukilteo, WA
  • Average snowfall in December: 1.18"

The month with the highest snowfall is February (4.61").
The months with the least snowfall are May, June, July, August, September and October (0").

Average snowfall days in December
Mukilteo, WA

Average snowfall days in December - Mukilteo, WA
  • Average snowfall days in December: 3.2 days

The month with the highest number of snowfall days is February (5.2 days).
The months with the least snowfall days are May, June, July, August, September and October (0 days).

Average sea temperature in December
Mukilteo, WA

Average sea temperature in December - Mukilteo, WA
  • Average sea temperature in December: 46.6°F

The best month for swimming (with the highest average sea temperature) is August (53.5°F).
The coldest month (with the lowest average sea temperature) is February (45.3°F).

Average daylight in December /
Average sunshine in December
Mukilteo, WA

Average daylight in December / Average sunshine in December - Mukilteo, WA
  • Average daylight in December: 8h and 3min

The month with the longest days is June (Average daylight: 16h and 0min).
The month with the shortest days is December (Average daylight: 8h and 30min).

  • Average sunshine in December: 4h and 3min

The month with the most sunshine is August (Average sunshine: 10h and 42min).
The month with the least sunshine is January (Average sunshine: 4h and 24min).

Average sunshine days in December
Mukilteo, WA

Average sunshine days in December - Mukilteo, WA
  • Average sunshine days in December: 10.7 days

The month with the most sunshine days is August (22.6 days).
The month with the least sunshine days is November (9.1 days).

Average UV index in December
Mukilteo, WA

Average UV index in December - Mukilteo, WA
  • Average UV index in December: 2

The month with the highest UV index is July (UV index 5).
The months with the lowest UV index are January, February, November and December (UV index 2).

Average cloud cover in December
Mukilteo, WA

Average cloud cover in December - Mukilteo, WA
  • Average cloud cover in December: 54

The month with the most cloud cover is December (Cloud cover 54).
The month with the least cloud cover is August (Cloud cover 25).

Average visibility in December
Mukilteo, WA

Average visibility in December - Mukilteo, WA
  • Average visibility in December: 6mi

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

Mukilteo, Washington, USA

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