December weather forecast
Mount Vernon, WA

Weather in December

The first month of the winter, December, is also a wintry month in Mount Vernon, Washington, with temperature in the range of an average low of 36.3°F (2.4°C) and an average high of 42.6°F (5.9°C).

Temperature

The coldest month is December, with an average high-temperature of 42.6°F (5.9°C) and an average low-temperature of 36.3°F (2.4°C).

Humidity

In December, the average relative humidity in Mount Vernon is 82%.

Rainfall

In Mount Vernon, Washington, it is raining for 19.5 days, with typically 4.06" (103mm) of accumulated precipitation. Throughout the year, in Mount Vernon, there are 185.2 rainfall days, and 34.72" (882mm) of precipitation is accumulated.

Snowfall

Months with snowfall are January through April, November and December. In Mount Vernon, during 1.5 snowfall days, 0.47" (12mm) of snow is typically accumulated. Throughout the year, there are 9.9 snowfall days, and 7.91" (201mm) of snow is accumulated.

Daylight

With an average of 8h and 23min of daylight, December has the shortest days of the year in Mount Vernon.
On the first day of December in Mount Vernon, sunrise is at 7:39 am and sunset at 4:17 pm. On the last day of the month, sunrise is at 8:00 am and sunset at 4:23 pm PST.

Sunshine

The month with the least sunshine in Mount Vernon is December, with an average of 3.9h of sunshine.

UV index

January, February, November and December, with an average maximum UV index of 2, are months with the lowest UV index in Mount Vernon. A UV Index of 2, and less, symbolizes a minimal health hazard from unsafe exposure to UV radiation for the ordinary person.
Note: The average daily UV index of 2 in December transform into the following instructions:
Extended sun exposure is not an issue for the majority. Children, infants, and fair-skinned individuals always need to be protected. The Sun's most intense and consequently most harmful UV radiation during midday hours should be decreased by minimizing exposure and seeking shade. Sun-protective clothing, a long-sleeved shirt and pants, a wide-brimmed hat, and UVA and UVB-blocking sunglasses are particularly helpful in blocking UV radiation's harmful effects. 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 Mount Vernon?

With an average high-temperature of 42.6°F (5.9°C) and an average low-temperature of 36.3°F (2.4°C), December is the coldest month in Mount Vernon.

What is the temperature in December in Mount Vernon?

In December, the average high-temperature is 42.6°F (5.9°C), and the average low-temperature is 36.3°F (2.4°C).

What is the average humidity in December in Mount Vernon?

The average relative humidity in December in Mount Vernon is 82%.

How many days does it rain in December in Mount Vernon?

In Mount Vernon, Washington, in December, during 19.5 rainfall days, 4.06" (103mm) of precipitation is typically accumulated.

How many days does it snow in December in Mount Vernon?

In December, in Mount Vernon, Washington, it is snowing for 1.5 days. Throughout December, 0.47" (12mm) of snow is accumulated.

What is the month with the shortest days in Mount Vernon?

The month with the shortest days in Mount Vernon is December, with an average of 8h and 23min of daylight.

What is the average length of the day in December in Mount Vernon?

In Mount Vernon, the average day length in December is 8h and 23min.

When are sunrise and sunset in December in Mount Vernon?

On the first day of December in Mount Vernon, sunrise is at 7:39 am and sunset at 4:17 pm. On the last day of the month, sunrise is at 8:00 am and sunset at 4:23 pm PST.

What is the month with the least sunshine in Mount Vernon?

December has the least sunshine of the year, with an average of 3.9h of sunshine.

How long on average sun shines in December in Mount Vernon?

The average sunshine duration in December in Mount Vernon, Washington, is 3.9h.

When is the lowest UV index in Mount Vernon?

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

How high is the UV index in December in Mount Vernon?

In December, the average daily maximum UV index in Mount Vernon is 2. A UV Index estimate of 2, and below, represents a minimal health vulnerability 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
Mount Vernon, WA

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

The warmest months (with the highest average high temperature) are July and August (68.4°F).
The month with the lowest average high temperature is December (42.6°F).

  • Average low temperature in December: 36.3°F

The month with the highest average low temperature is August (54.1°F).
The coldest month (with the lowest average low temperature) is February (36.1°F).

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Average pressure in December
Mount Vernon, WA

Average pressure in December - Mount Vernon, WA
  • Average pressure in December: 30.07"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).

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Average wind speed in December
Mount Vernon, WA

Average wind speed in December - Mount Vernon, WA
  • Average wind speed in December: 7.2mph

The windiest month (with the highest average wind speed) is November (7.5mph).
The calmest month (with the lowest average wind speed) is August (3.7mph).

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Average humidity in December
Mount Vernon, WA

Average humidity in December - Mount Vernon, WA
  • Average humidity in December: 82%

The months with the highest relative humidity are January and February (83%).
The month with the lowest relative humidity is July (75%).

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Average rainfall in December
Mount Vernon, WA

Average rainfall in December - Mount Vernon, WA
  • Average rainfall in December: 4.06"

The wettest month (with the highest rainfall) is November (4.96").
The driest month (with the least rainfall) is July (0.63").

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Average rainfall days in December
Mount Vernon, WA

Average rainfall days in December - Mount Vernon, WA
  • Average rainfall days in December: 19.5 days

The month with the highest number of rainy days is March (20.8 days).
The month with the least rainy days is August (7.2 days).

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Average snowfall in December
Mount Vernon, WA

Average snowfall in December - Mount Vernon, WA
  • Average snowfall in December: 0.47"

The month with the highest snowfall is February (3.54").
The months with the least snowfall are May, June, July, August, September and October (0").

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Average snowfall days in December
Mount Vernon, WA

Average snowfall days in December - Mount Vernon, WA
  • Average snowfall days in December: 1.5 days

The month with the highest number of snowfall days is February (3.6 days).
The months with the least snowfall days are May, June, July, August, September and October (0 days).

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Average daylight in December /
Average sunshine in December
Mount Vernon, WA

Average daylight in December / Average sunshine in December - Mount Vernon, WA
  • Average daylight in December: 8h and 23min

The month with the longest days is June (Average daylight: 16h and 2min).
The month with the shortest days is December (Average daylight: 8h and 23min).

  • Average sunshine in December: 3h and 54min

The months with the most sunshine are July and August (Average sunshine: 10h and 24min).
The month with the least sunshine is December (Average sunshine: 3h and 54min).

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Average sunshine days in December
Mount Vernon, WA

Average sunshine days in December - Mount Vernon, WA
  • Average sunshine days in December: 9.9 days

The month with the most sunshine days is August (22.3 days).
The month with the least sunshine days is November (8.1 days).

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Average UV index in December
Mount Vernon, WA

Average UV index in December - Mount Vernon, 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).

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Average cloud cover in December
Mount Vernon, WA

Average cloud cover in December - Mount Vernon, WA
  • Average cloud cover in December: 59

The month with the most cloud cover is December (Cloud cover 59).
The month with the least cloud cover is August (Cloud cover 26).

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Average visibility in December
Mount Vernon, WA

Average visibility in December - Mount Vernon, WA
  • Average visibility in December: 6mi

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

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