December weather forecastMount Vernon, OR
December
Weather in December
December, the first month of the winter in Mount Vernon, is also an icy month, with an average temperature varying between 19.6°F (-6.9°C) and 33.4°F (0.8°C).Temperature
With average high temperatures of 33.4°F (0.8°C) and lows of 19.6°F (-6.9°C), December is the coldest month.Humidity
In December, the average relative humidity is 84%.Rainfall
In Mount Vernon, during December, the rain falls for 11.1 days and regularly aggregates up to 2.24" (57mm) of precipitation. In Mount Vernon, during the entire year, the rain falls for 127.7 days and collects up to 17.09" (434mm) of precipitation.Snowfall
January through May, September through December are months with snowfall. In Mount Vernon, in December, snow falls for 14.5 days, with typically accumulated 8.31" (211mm) of snow. Throughout the year, there are 62.5 snowfall days, and 39.17" (995mm) of snow is accumulated.Daylight
The month with the shortest days is December, 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, in Mount Vernon, Oregon, sunrise is at 7:32 am and sunset at 4:27 pm PST.
Sunshine
The average sunshine in December is 5.3h.UV index
The months with the lowest UV index are January through March, October through December, with an average maximum UV index of 2. A UV Index estimate of 2, and below, represents a minimal health hazard from exposure to the Sun's UV rays for average individuals.Note: The daily maximum UV index of 2 in December interprets into the following advice:
Babies, children, and those with sensitive skin should always avoid extended periods in the sun. Avoid the Sun's strongest UV rays by seeking shade and limiting exposure during midday. Protect your eyes, ears, face, and neck from the Sun by wearing a wide-brimmed hat. Warning! The reflection from snow can nearly magnify the Sun's UV radiation twofold.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
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 54min
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 18min
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).
