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
The shift into December is marked by a considerable temperature decrease, with the average high-temperature dropping from a chilly 45°F (7.2°C) in November to a subzero cold 28.6°F (-1.9°C). Mount Vernon, during the nights of December, experiences an average temperature drop to a still freezing cold 16°F (-8.9°C).Humidity
In December, the average relative humidity in Mount Vernon is 83%.Rainfall
In Mount Vernon, in December, during 2.9 rainfall days, 0.51" (13mm) of precipitation is typically accumulated. In Mount Vernon, during the entire year, the rain falls for 93.2 days and collects up to 11.3" (287mm) of precipitation.Snowfall
Months with snowfall are January through April, October through December. In Mount Vernon, during December, snow falls for 7.5 days and regularly aggregates up to 1.1" (28mm) of snow. Throughout the year, in Mount Vernon, there are 35.3 snowfall days, and 7.17" (182mm) of snow is accumulated.Daylight
December has the shortest days of the year in Mount Vernon, with an average of 9h and 0min of daylight.On the first day of December, sunrise is at 7:47 am and sunset at 4:57 pm. On the last day of the month, sunrise is at 8:06 am and sunset at 5:06 pm CST.
Sunshine
In Mount Vernon, the average sunshine in December is 4.7h.UV index
In December, the average daily maximum UV index is 2. A UV Index of 2, and less, symbolizes a minimal health vulnerability from unprotected exposure to Sun's UV rays for the ordinary person.Note: A typical high UV index of 2 in December suggests the following recommendations:
Extended exposure to the sun should always be avoided by children, infants, and those with sensitive skin. Sun's radiation is most powerful around mid-day, so it's best to limit outdoor activities during this time. To cut down UV radiation exposure by about half, sport a wide-brim hat. Forewarned is forearmed! The Sun's UV radiation can be almost doubled in intensity by snow reflection.
Frequently asked questions
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 many days does it snow in December in Mount Vernon?
What is the month with the shortest days in Mount Vernon?
How many hours of daylight does Mount Vernon have in December?
What time are sunrise and sunset in December in Mount Vernon?
How long on average sun shines in December in Mount Vernon?
How high is the UV index in December in Mount Vernon?
Average temperature in December
Mount Vernon, SD
- Average high temperature in December: 28.6°F
The warmest month (with the highest average high temperature) is July (85.6°F).
The month with the lowest average high temperature is January (24.4°F).
- Average low temperature in December: 16°F
The month with the highest average low temperature is July (64.6°F).
The coldest month (with the lowest average low temperature) is January (10.2°F).
Average pressure in December
Mount Vernon, SD
- Average pressure in December: 30.13"Hg
The months with the highest atmospheric pressure are January and February (30.16"Hg).
The month with the lowest atmospheric pressure is June (29.85"Hg).
Average wind speed in December
Mount Vernon, SD
- Average wind speed in December: 10.1mph
The windiest month (with the highest average wind speed) is April (11.2mph).
The calmest month (with the lowest average wind speed) is July (8.6mph).
Average humidity in December
Mount Vernon, SD
- Average humidity in December: 83%
The month with the highest relative humidity is January (87%).
The months with the lowest relative humidity are September and October (63%).
Average rainfall in December
Mount Vernon, SD
- Average rainfall in December: 0.51"
The wettest month (with the highest rainfall) is May (1.65").
The driest months (with the least rainfall) are February and November (0.28").
Average rainfall days in December
Mount Vernon, SD
- Average rainfall days in December: 2.9 days
The month with the highest number of rainy days is June (13.6 days).
The month with the least rainy days is February (1.9 days).
Average snowfall in December
Mount Vernon, SD
- Average snowfall in December: 1.1"
The month with the highest snowfall is February (1.42").
The months with the least snowfall are May, June, July, August and September (0").
Average snowfall days in December
Mount Vernon, SD
- Average snowfall days in December: 7.5 days
The month with the highest number of snowfall days is January (8.7 days).
The months with the least snowfall days are June, July, August and September (0 days).
Average daylight in December /
Average sunshine in December
Mount Vernon, SD
- Average daylight in December: 9h and 0min
The month with the longest days is June (Average daylight: 15h and 24min).
The month with the shortest days is December (Average daylight: 9h and 0min).
- Average sunshine in December: 4h and 4min
The month with the most sunshine is July (Average sunshine: 11h and 6min).
The month with the least sunshine is January (Average sunshine: 4h and 24min).
Average sunshine days in December
Mount Vernon, SD
- Average sunshine days in December: 21.9 days
The month with the most sunshine days is November (23.4 days).
The month with the least sunshine days is June (12.8 days).
Average UV index in December
Mount Vernon, SD
- Average UV index in December: 2
The months with the highest UV index are June, July and August (UV index 6).
The month with the lowest UV index is January (UV index 1).
Average cloud cover in December
Mount Vernon, SD
- Average cloud cover in December: 49
The month with the most cloud cover is January (Cloud cover 52).
The month with the least cloud cover is July (Cloud cover 22).
Average visibility in December
Mount Vernon, SD
- Average visibility in December: 6mi
The months with the highest visibility are January, February, March, April, May, June, July, August, September, October, November and December (6mi).
The months with the lowest visibility are January, February, March, April, May, June, July, August, September, October, November and December (6mi).
Mount Vernon, South Dakota, USA
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