December weather forecastVashon, WA
December
Weather in December
The first month of the winter, December, is still a chilly month in Vashon, Washington, with an average temperature ranging between min 34.3°F (1.3°C) and max 43.5°F (6.4°C).Temperature
Vashon's December weather reaches an average high of 43.5°F (6.4°C) and an average low of 34.3°F (1.3°C), making it the coldest month.Humidity
The months with the highest humidity are January and December, with an average relative humidity of 85%.Rainfall
The month with the most rainfall is December, when the rain falls for 13.5 days and typically aggregates up to 2.2" (56mm) of precipitation.Snowfall
Months with snowfall are January through March, November and December. In Vashon, during December, snow falls for 1.6 days and regularly aggregates up to 0.47" (12mm) of snow. Throughout the year, there are 9.8 snowfall days, and 4.72" (120mm) of snow is accumulated.Daylight
December has the shortest days of the year, with an average of 8h and 30min of daylight.On the first day of December, sunrise is at 7:37 am and sunset at 4:20 pm. On the last day of the month, sunrise is at 7:57 am and sunset at 4:29 pm PST.
Sunshine
December has the least sunshine of the year, with an average of 4.1h of sunshine.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 reading of 2, and below, represents a minimal health vulnerability from exposure to the Sun's UV rays for average individuals.Note: A daily high UV index of 2 in December leads to these guidelines:
Unlike children, who always need sun protection, most individuals can remain in the sun for up to an hour without getting burnt. The solar radiation is most powerful near the mid-day, so the exposure to the direct Sun should be reduced accordingly. Always opt for UVA and UVB-resistant sunglasses on radiant days. Remember to consider! The UV radiation from the Sun can be intensified nearly twice by the reflection of snow.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in December
Vashon, WA
- Average high temperature in December: 43.5°F
The warmest month (with the highest average high temperature) is August (77.7°F).
The month with the lowest average high temperature is December (43.5°F).
- Average low temperature in December: 34.3°F
The month with the highest average low temperature is August (53.6°F).
The coldest month (with the lowest average low temperature) is December (34.3°F).
Average pressure in December
Vashon, WA
- Average pressure in December: 30.08"Hg
The month with the highest atmospheric pressure is January (30.1"Hg).
The months with the lowest atmospheric pressure are March, August and September (30.01"Hg).
Average wind speed in December
Vashon, WA
- Average wind speed in December: 4.8mph
The windiest month (with the highest average wind speed) is March (5.3mph).
The calmest months (with the lowest average wind speed) are July and August (3.6mph).
Average humidity in December
Vashon, WA
- Average humidity in December: 85%
The months with the highest relative humidity are January and December (85%).
The month with the lowest relative humidity is July (68%).
Average rainfall in December
Vashon, WA
- Average rainfall in December: 2.2"
The wettest month (with the highest rainfall) is December (2.2").
The driest month (with the least rainfall) is July (0.31").
Average rainfall days in December
Vashon, WA
- Average rainfall days in December: 13.5 days
The month with the highest number of rainy days is April (14.9 days).
The month with the least rainy days is August (5.7 days).
Average snowfall in December
Vashon, WA
- Average snowfall in December: 0.47"
The month with the highest snowfall is February (2.52").
The months with the least snowfall are April, May, June, July, August, September and October (0").
Average snowfall days in December
Vashon, WA
- Average snowfall days in December: 1.6 days
The month with the highest number of snowfall days is February (3.4 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
Vashon, WA
- Average daylight in December: 8h and 30min
The month with the longest days is June (Average daylight: 15h and 54min).
The month with the shortest days is December (Average daylight: 8h and 30min).
- Average sunshine in December: 4h and 6min
The month with the most sunshine is August (Average sunshine: 10h and 42min).
The month with the least sunshine is December (Average sunshine: 4h and 6min).
Average sunshine days in December
Vashon, WA
- Average sunshine days in December: 14.2 days
The month with the most sunshine days is August (22.8 days).
The month with the least sunshine days is February (13 days).
Average UV index in December
Vashon, WA
- Average UV index in December: 2
The months with the highest UV index are June, July and August (UV index 5).
The months with the lowest UV index are January, February, November and December (UV index 2).
Average cloud cover in December
Vashon, WA
- Average cloud cover in December: 58
The month with the most cloud cover is December (Cloud cover 58).
The month with the least cloud cover is August (Cloud cover 26).
Average visibility in December
Vashon, WA
- Average visibility in December: 5mi
The months with the highest visibility are May, June, July, August and September (6mi).
The months with the lowest visibility are January, February, March, April, October, November and December (5mi).
