December weather forecastMount Vernon, SD
December
Weather in December
December, the first month of the winter in Mount Vernon, is also a subzero cold month, with an average temperature varying between 16°F (-8.9°C) and 28.6°F (-1.9°C).Temperature
December signals a significant shift in the average high-temperature, falling from November's frosty 45°F (7.2°C) to a subzero cold 28.6°F (-1.9°C). Mount Vernon records an average nighttime low of 16°F (-8.9°C) in December.Humidity
In Mount Vernon, the average relative humidity in December is 83%.Rainfall
In Mount Vernon, South Dakota, in December, it is raining for 2.9 days, with typically 0.51" (13mm) of accumulated precipitation. In Mount Vernon, during the entire year, the rain falls for 93.2 days and collects up to 11.3" (287mm) of precipitation.Snowfall
January through April, October through December are months with snowfall. In Mount Vernon, in December, during 7.5 snowfall days, 1.1" (28mm) of snow is typically accumulated. In Mount Vernon, during the entire year, snow falls for 35.3 days and aggregates up to 7.17" (182mm) of snow.Daylight
With an average of 9h and 0min of daylight, December has the shortest days of the year.On the first day of December in Mount Vernon, 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, South Dakota, the average sunshine in December is 4.7h.UV index
In Mount Vernon, the average daily maximum UV index in December is 2. A UV Index value of 2, and less, symbolizes a minimal health vulnerability from unprotected exposure to Sun's UV rays for the average person.Note: A daily maximum UV index of 2 in December translates into the following instructions:
Although the majority can endure up to an hour in the sun without burns, children always require sun protection. The Sun is at its harshest during midday; protect yourself by staying in shaded areas and minimizing exposure. A hat with a generous brim can prevent nearly 50% of UV rays from reaching your eyes. Take heed! The reflection of snow can intensify the Sun's UV radiation nearly double.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
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 42min
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).
