December weather forecastRapid Valley, SD
December
Weather in December
The first month of the winter, December, is also an icy month in Rapid Valley, South Dakota, with temperature in the range of an average low of 18.7°F (-7.4°C) and an average high of 32.5°F (0.3°C).Temperature
December is the coldest month, exhibiting average temperatures of 32.5°F (0.3°C) at the peak and 18.7°F (-7.4°C) at the base.Humidity
In Rapid Valley, the average relative humidity in December is 74%.Rainfall
In Rapid Valley, in December, it is raining for 4.8 days, with typically 0.63" (16mm) of accumulated precipitation. Throughout the year, there are 118.8 rainfall days, and 15.39" (391mm) of precipitation is accumulated.Snowfall
January through May, September through December are months with snowfall. In Rapid Valley, in December, during 8.1 snowfall days, 2.64" (67mm) of snow is typically accumulated. In Rapid Valley, during the entire year, snow falls for 50.4 days and aggregates up to 24.41" (620mm) of snow.Daylight
With an average of 8h and 54min of daylight, December has the shortest days of the year in Rapid Valley.On the first day of December, sunrise is at 7:08 am and sunset at 4:15 pm. On the last day of the month, sunrise is at 7:27 am and sunset at 4:24 pm MST.
Sunshine
In December, the average sunshine in Rapid Valley, South Dakota, is 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 of 2, and less, symbolizes a low health risk from unprotected exposure to Sun's UV rays for the ordinary person.Note: In December, a daily maximum UV index of 2 leads to the following instructions:
While most can endure approximately an hour in the sun without burning, children always require protection from sunlight. The intensity of the Sun's UV radiation during midday suggests reducing time spent outdoors. Stay sun-safe with clothing that is both closely woven and worn loosely. Foresee this! The reflection from snow can nearly double the intensity of UV radiation from the Sun.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in December
Rapid Valley, SD
- Average high temperature in December: 32.5°F
The warmest month (with the highest average high temperature) is July (84.7°F).
The month with the lowest average high temperature is December (32.5°F).
- Average low temperature in December: 18.7°F
The month with the highest average low temperature is July (63.3°F).
The coldest month (with the lowest average low temperature) is February (17.8°F).
Average pressure in December
Rapid Valley, SD
- Average pressure in December: 30.13"Hg
The month with the highest atmospheric pressure is January (30.14"Hg).
The month with the lowest atmospheric pressure is June (29.84"Hg).
Average wind speed in December
Rapid Valley, SD
- Average wind speed in December: 8.9mph
The windiest month (with the highest average wind speed) is April (10.3mph).
The calmest month (with the lowest average wind speed) is August (8.2mph).
Average humidity in December
Rapid Valley, SD
- Average humidity in December: 74%
The month with the highest relative humidity is January (77%).
The months with the lowest relative humidity are August and September (50%).
Average rainfall in December
Rapid Valley, SD
- Average rainfall in December: 0.63"
The wettest month (with the highest rainfall) is May (2.28").
The driest month (with the least rainfall) is January (0.43").
Average rainfall days in December
Rapid Valley, SD
- Average rainfall days in December: 4.8 days
The month with the highest number of rainy days is May (17.1 days).
The month with the least rainy days is December (4.8 days).
Average snowfall in December
Rapid Valley, SD
- Average snowfall in December: 2.64"
The month with the highest snowfall is April (5.43").
The months with the least snowfall are June, July and August (0").
Average snowfall days in December
Rapid Valley, SD
- Average snowfall days in December: 8.1 days
The month with the highest number of snowfall days is February (10.5 days).
The months with the least snowfall days are June, July and August (0 days).
Average daylight in December /
Average sunshine in December
Rapid Valley, SD
- Average daylight in December: 8h and 54min
The month with the longest days is June (Average daylight: 15h and 24min).
The month with the shortest days is December (Average daylight: 8h and 54min).
- Average sunshine in December: 6h and 0min
The month with the most sunshine is August (Average sunshine: 11h and 48min).
The month with the least sunshine is February (Average sunshine: 5h and 54min).
Average sunshine days in December
Rapid Valley, SD
- Average sunshine days in December: 19.6 days
The month with the most sunshine days is November (20.2 days).
The month with the least sunshine days is May (11 days).
Average UV index in December
Rapid Valley, SD
- Average UV index in December: 2
The months with the highest UV index are June and July (UV index 6).
The months with the lowest UV index are January, February, November and December (UV index 2).
Average cloud cover in December
Rapid Valley, SD
- Average cloud cover in December: 36
The months with the most cloud cover are February and April (Cloud cover 38).
The month with the least cloud cover is August (Cloud cover 16).
Average visibility in December
Rapid Valley, 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).





