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
In Mount Vernon, December records the lowest average temperatures, peaking at 33.4°F (0.8°C) and reaching a low of 19.6°F (-6.9°C).Humidity
In December, the average relative humidity is 84%.Rainfall
In Mount Vernon, in December, during 11.1 rainfall days, 2.24" (57mm) of precipitation is typically accumulated. In Mount Vernon, during the entire year, the rain falls for 127.7 days and collects up to 17.09" (434mm) of precipitation.Snowfall
Months with snowfall in Mount Vernon are January through May, September through December. In Mount Vernon, Oregon, during December, snow falls for 14.5 days and regularly aggregates up to 8.31" (211mm) of snow. Throughout the year, there are 62.5 snowfall days, and 39.17" (995mm) of snow is accumulated.Daylight
December has the shortest days of the year, with an average of 8h and 54min of daylight.On the first day of the month, sunrise is at 7:13 am and sunset at 4:18 pm. On the last day of December, sunrise is at 7:32 am and sunset at 4:27 pm PST.
Sunshine
In Mount Vernon, the average sunshine in December is 5.3h.UV index
January through March, October through December, with an average maximum UV index of 2, are months with the lowest UV index in Mount Vernon, Oregon. A UV Index estimate of 2, and below, represents a minimal health vulnerability from exposure to the Sun's UV rays for the average person.Note: A daily high UV index of 2 in December leads to these guidelines:
People with sensitive skin, children, and babies should always be protected from prolonged sun exposure. Avoiding direct sunlight during midday hours helps reduce the risk from intense UV radiation. To mitigate harm from sun exposure, pick sunglasses offering UVA and UVB defense. Warning! The reflection from snow can nearly magnify the Sun's UV radiation twofold.
Frequently asked questions
What part of the year is the coldest in Mount Vernon?
How cold is it in Mount Vernon in December?
What is the average humidity in December in Mount Vernon?
How much does it rain in Mount Vernon in December?
How much does it snow in Mount Vernon in December?
What is the month with the shortest days in Mount Vernon?
What is the average length of the day in December in Mount Vernon?
When is the sunrise / sunset in December in Mount Vernon?
How long on average sun shines in December in Mount Vernon?
What are the months with the lowest UV index in Mount Vernon?
What is the UV index intensity in December in Mount Vernon?
Average temperature in December
Mount Vernon, OR
- Average high temperature in December: 33.4°F
The warmest month (with the highest average high temperature) is July (81.7°F).
The month with the lowest average high temperature is December (33.4°F).
- Average low temperature in December: 19.6°F
The month with the highest average low temperature is August (49.6°F).
The coldest month (with the lowest average low temperature) is December (19.6°F).
Average pressure in December
Mount Vernon, OR
- Average pressure in December: 30.19"Hg
The month with the highest atmospheric pressure is January (30.22"Hg).
The month with the lowest atmospheric pressure is August (29.93"Hg).
Average wind speed in December
Mount Vernon, OR
- Average wind speed in December: 5.8mph
The windiest month (with the highest average wind speed) is April (6.2mph).
The calmest months (with the lowest average wind speed) are August and September (5mph).
Average humidity in December
Mount Vernon, OR
- Average humidity in December: 84%
The month with the highest relative humidity is February (85%).
The month with the lowest relative humidity is August (42%).
Average rainfall in December
Mount Vernon, OR
- Average rainfall in December: 2.24"
The wettest month (with the highest rainfall) is February (2.28").
The driest month (with the least rainfall) is July (0.24").
Average rainfall days in December
Mount Vernon, OR
- Average rainfall days in December: 11.1 days
The month with the highest number of rainy days is March (17.3 days).
The month with the least rainy days is August (3.3 days).
Average snowfall in December
Mount Vernon, OR
- Average snowfall in December: 8.31"
The month with the highest snowfall is February (10.31").
The months with the least snowfall are June, July and August (0").
Average snowfall days in December
Mount Vernon, OR
- Average snowfall days in December: 14.5 days
The month with the highest number of snowfall days is December (14.5 days).
The months with the least snowfall days are June, July and August (0 days).
Average daylight in December /
Average sunshine in December
Mount Vernon, OR
- Average daylight in December: 8h and 5min
The month with the longest days is June (Average daylight: 15h and 30min).
The month with the shortest days is December (Average daylight: 8h and 54min).
- Average sunshine in December: 5h and 2min
The month with the most sunshine is August (Average sunshine: 12h and 6min).
The months with the least sunshine are January and February (Average sunshine: 5h and 12min).
Average sunshine days in December
Mount Vernon, OR
- Average sunshine days in December: 11.4 days
The month with the most sunshine days is July (24.9 days).
The month with the least sunshine days is February (9 days).
Average UV index in December
Mount Vernon, OR
- Average UV index in December: 2
The month with the highest UV index is July (UV index 6).
The months with the lowest UV index are January, February, March, October, November and December (UV index 2).
Average cloud cover in December
Mount Vernon, OR
- Average cloud cover in December: 47
The month with the most cloud cover is February (Cloud cover 49).
The months with the least cloud cover are July and August (Cloud cover 9).
Average visibility in December
Mount Vernon, OR
- Average visibility in December: 4mi
The months with the highest visibility are April, May, June, July, August, September and October (6mi).
The months with the lowest visibility are January, February and December (4mi).
Mount Vernon, Oregon, USA
Weather forecast for your location
2. Allow the app to use your location
