Contents
- Weather in December
- Frequently asked questions
- Average temperature in December
- Average pressure in December
- Average wind speed in December
- Average humidity in December
- Average rainfall in December
- Average rainfall days in December
- Average snowfall in December
- Average snowfall days in December
- Average daylight in December
- Average sunshine in December
- Average sunshine days in December
- Average UV index in December
- Average cloud cover in December
- Average visibility in December
Weather in December
Temperature
With an average high-temperature of 43.3°F (6.3°C) and an average low-temperature of 35.8°F (2.1°C), December is the coldest month.Humidity
January, February and December, with an average relative humidity of 84%, are the most humid months in Mountlake Terrace.Rainfall
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.Snowfall
Months with snowfall in Mountlake Terrace are January through April, November and December. In Mountlake Terrace, in December, during 2.2 snowfall days, 0.43" (11mm) of snow is typically accumulated. In Mountlake Terrace, during the entire year, snow falls for 12.5 days and aggregates up to 6.65" (169mm) of snow.Daylight
December has the shortest days of the year, with an average of 8h and 30min of daylight.On the first day of the month, sunrise is at 7:38 am and sunset at 4:19 pm. On the last day of December, in Mountlake Terrace, sunrise is at 7:58 am and sunset at 4:27 pm PST.
Sunshine
In Mountlake Terrace, the average sunshine in December is 4.6h.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 estimate of 2, and below, represents a low health risk from exposure to the Sun's UV radiation for average individuals.Note: The UV index of 2 in December translates into these instructions:
People with sensitive skin, children, and babies should always be protected from prolonged sun exposure. When the Sun is at its strongest around midday, find shade and limit exposure. Experience reduced UV exposure by about half when donning a wide-brim hat. Heads up! The UV radiation from the Sun can almost be doubled by snow reflection.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
What time of the year is the coldest in Mountlake Terrace?
How cold is it in Mountlake Terrace in December?
What is the most humid month in Mountlake Terrace?
What is the average humidity in December in Mountlake Terrace?
What is the wettest month in Mountlake Terrace?
How many days does it rain in December in Mountlake Terrace?
How much does it snow in Mountlake Terrace in December?
What is the month with the shortest days in Mountlake Terrace?
What is the average length of the day in December in Mountlake Terrace?
When is the sunrise / sunset in December in Mountlake Terrace?
How many hours of sunshine does Mountlake Terrace have in December?
What is the month with the lowest UV index in Mountlake Terrace?
What is the UV index intensity in December in Mountlake Terrace?
Average temperature in December
Mountlake Terrace, 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
Mountlake Terrace, 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
Mountlake Terrace, 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
Mountlake Terrace, 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
Mountlake Terrace, 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
Mountlake Terrace, 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
Mountlake Terrace, 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
Mountlake Terrace, 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
Mountlake Terrace, WA
- Average daylight in December: 8h and 3min
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 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
Mountlake Terrace, 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
Mountlake Terrace, 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
Mountlake Terrace, 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
Mountlake Terrace, 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).
Mountlake Terrace, Washington, USA
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