December weather forecast
Lynnwood, WA

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Weather in December

December announces the arrival of winter in Lynnwood with the lowest temperatures observed during the year and frequent showers. Humidity soars high, tying with January, yielding a relative humidity of 84%, the highest of the year. Both the falling temperatures and increasing rainfall, noted at 3.5" (89mm), signal the peak of winter. To end the year, December paints a vivid picture of conventional winter weather.

Temperature

Lynnwood's temperature records reveal December as the coldest month, marked by average highs of 43.3°F (6.3°C) and lows of 35.8°F (2.1°C).

Humidity

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

Rainfall

December is the month with the most rainfall. Rain falls for 17.6 days and accumulates 3.5" (89mm) of precipitation.

Snowfall

January through April, November and December are months with snowfall. In Lynnwood, in December, during 2.2 snowfall days, 0.43" (11mm) of snow is typically accumulated. Throughout the year, there are 12.5 snowfall days, and 6.65" (169mm) of snow is accumulated.

Daylight

The month with the shortest days is December, with an average of 8h and 30min of daylight.
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 4:27 pm PST.

Sunshine

The average sunshine in December is 4.6h.

UV index

The months with the lowest UV index are January, February, November and December, with an average maximum UV index of 2. A UV Index of 2, and less, symbolizes a minimal health vulnerability from exposure to the Sun's UV rays for average individuals.
Note: The maximum UV index of 2 during December translates into these guidelines:
Long-term sun exposure is typically not a concern for most. However, those with sensitive skin, infants, and children must always have protection. Avoiding direct sunlight during midday hours helps reduce the risk from intense UV radiation. A wide-brimmed hat is a shield, deflecting up to 50% of harmful UV radiation from eyes. Mind you! Snow reflection can increase the intensity of the Sun's UV radiation nearly twofold.
Updated: Jul 21, 2024
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate

Frequently asked questions

What is the coldest time of year?

December is the month that records the lowest temperatures, with averages ranging from a high of 43.3°F (6.3°C) to a low of 35.8°F (2.1°C).

How cold is it in December?

In Lynnwood, 43.3°F (6.3°C) is the average high-temperature and 35.8°F (2.1°C) is the average low-temperature during December.

What is the most humid month?

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

What is the average humidity in December?

The average relative humidity in December is 84%.

What is the wettest month?

The month with the most rainfall is December, when the rain falls for 17.6 days and typically aggregates up to 3.5" (89mm) of precipitation.

How much does it rain in December?

In December, the rain falls for 17.6 days. Throughout December, 3.5" (89mm) of precipitation is accumulated.

How much does it snow in December?

In Lynnwood, in December, during 2.2 snowfall days, 0.43" (11mm) of snow is typically accumulated.

What is the month with the shortest days?

The month with the shortest days in Lynnwood is December, with an average of 8h and 30min of daylight.

How many hours of daylight does Lynnwood have in December?

In December, the average day length in Lynnwood is 8h and 29min.

When is the sunrise / 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 4:27 pm PST.

How many hours of sunshine does Lynnwood have in December?

In Lynnwood, the average sunshine duration in December is 4.6h.

What are the months 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 Lynnwood, the average daily maximum UV index in December is 2. A UV Index of 2, and less, symbolizes 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
Lynnwood, WA

Average temperature in December - Lynnwood, WA
  • Average high temperature in December: 43.3°F

The warmest month (with the highest average high temperature) is August (73.9°F).
The month with the lowest average high temperature is December (43.3°F).

  • Average low temperature in December: 35.8°F

The month with the highest average low temperature is August (54.1°F).
The coldest month (with the lowest average low temperature) is December (35.8°F).

Average pressure in December
Lynnwood, WA

Average pressure in December - Lynnwood, 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
Lynnwood, WA

Average wind speed in December - Lynnwood, WA
  • Average wind speed in December: 5.5mph

The windiest month (with the highest average wind speed) is November (5.9mph).
The calmest month (with the lowest average wind speed) is August (3.5mph).

Average humidity in December
Lynnwood, WA

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

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

Average rainfall in December
Lynnwood, WA

Average rainfall in December - Lynnwood, WA
  • Average rainfall in December: 3.5"

The wettest month (with the highest rainfall) is December (3.5").
The driest month (with the least rainfall) is July (0.39").

Average rainfall days in December
Lynnwood, WA

Average rainfall days in December - Lynnwood, WA
  • Average rainfall days in December: 17.6 days

The month with the highest number of rainy days is March (19.8 days).
The month with the least rainy days is August (6.8 days).

Average snowfall in December
Lynnwood, WA

Average snowfall in December - Lynnwood, WA
  • Average snowfall in December: 0.43"

The month with the highest snowfall is February (3.58").
The months with the least snowfall are May, June, July, August, September and October (0").

Average snowfall days in December
Lynnwood, WA

Average snowfall days in December - Lynnwood, WA
  • Average snowfall days in December: 2.2 days

The month with the highest number of snowfall days is February (4.7 days).
The months with the least snowfall days are May, June, July, August, September and October (0 days).

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

Average daylight in December / Average sunshine in December - Lynnwood, 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 4min

The month with the most sunshine is August (Average sunshine: 10h and 48min).
The month with the least sunshine is January (Average sunshine: 4h and 30min).

Average sunshine days in December
Lynnwood, WA

Average sunshine days in December - Lynnwood, WA
  • Average sunshine days in December: 10.8 days

The month with the most sunshine days is August (22.5 days).
The month with the least sunshine days is November (9.2 days).

Average UV index in December
Lynnwood, WA

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

The months with the highest UV index are June and 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
Lynnwood, WA

Average cloud cover in December - Lynnwood, WA
  • Average cloud cover in December: 53

The months with the most cloud cover are January and December (Cloud cover 53).
The month with the least cloud cover is August (Cloud cover 25).

Average visibility in December
Lynnwood, WA

Average visibility in December - Lynnwood, 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).

Lynnwood, Washington, USA

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