December weather forecastLong Valley, SD
December
Weather in December
The first month of the winter, December, is also a subzero cold month in Long Valley, South Dakota, with an average temperature ranging between min 18°F (-7.8°C) and max 30.7°F (-0.7°C).Temperature
As Long Valley transitions into December, the average high-temperature shows a marked reduction, decreasing from a frosty 46.4°F (8°C) in November to a freezing cold 30.7°F (-0.7°C). December nights in Long Valley observe an average temperature dip to a still subzero cold 18°F (-7.8°C).Humidity
In December, the average relative humidity is 79%.Rainfall
In Long Valley, during December, the rain falls for 2.7 days and regularly aggregates up to 0.71" (18mm) of precipitation. Throughout the year, in Long Valley, there are 95.3 rainfall days, and 13.74" (349mm) of precipitation is accumulated.Snowfall
Months with snowfall in Long Valley are January through May, October through December. In Long Valley, in December, during 6.9 snowfall days, 2.95" (75mm) of snow is typically accumulated. Throughout the year, there are 38.8 snowfall days, and 16.1" (409mm) of snow is accumulated.Daylight
December has the shortest days of the year in Long Valley, with an average of 9h and 0min of daylight.On the first day of December, sunrise is at 6:59 am and sunset at 4:10 pm. On the last day of the month, sunrise is at 7:18 am and sunset at 4:19 pm MST.
Sunshine
In December, the average sunshine is 5.3h.UV index
December is the month with the lowest UV index, with an average maximum UV index of 1. A UV Index estimate of 2, and below, represents a minimal health vulnerability from unsafe exposure to UV radiation for ordinary individuals.Note: In December, the UV index of 1 transforms into the following advice:
Extended sun exposure is not an issue for the majority. Children, infants, and fair-skinned individuals always need to be protected. The midday Sun can be dangerous due to its intense radiation; always find shade and reduce exposure. Opt for tightly woven and loose clothing to enhance protection from the Sun. Heads up! The UV radiation from the Sun can almost be doubled by snow reflection.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in December
Long Valley, SD
- Average high temperature in December: 30.7°F
The warmest month (with the highest average high temperature) is July (89.2°F).
The month with the lowest average high temperature is January (29.8°F).
- Average low temperature in December: 18°F
The month with the highest average low temperature is July (68.5°F).
The coldest month (with the lowest average low temperature) is January (16.7°F).
Average pressure in December
Long Valley, SD
- Average pressure in December: 30.13"Hg
The month with the highest atmospheric pressure is January (30.15"Hg).
The month with the lowest atmospheric pressure is June (29.85"Hg).
Average wind speed in December
Long Valley, SD
- Average wind speed in December: 10.3mph
The windiest month (with the highest average wind speed) is April (12.1mph).
The calmest month (with the lowest average wind speed) is February (10.1mph).
Average humidity in December
Long Valley, SD
- Average humidity in December: 79%
The month with the highest relative humidity is January (81%).
The month with the lowest relative humidity is September (47%).
Average rainfall in December
Long Valley, SD
- Average rainfall in December: 0.71"
The wettest month (with the highest rainfall) is May (2.09").
The driest month (with the least rainfall) is January (0.39").
Average rainfall days in December
Long Valley, SD
- Average rainfall days in December: 2.7 days
The month with the highest number of rainy days is May (13.5 days).
The month with the least rainy days is February (2.6 days).
Average snowfall in December
Long Valley, SD
- Average snowfall in December: 2.95"
The month with the highest snowfall is February (3.15").
The months with the least snowfall are June, July, August and September (0").
Average snowfall days in December
Long Valley, SD
- Average snowfall days in December: 6.9 days
The month with the highest number of snowfall days is February (8.9 days).
The months with the least snowfall days are June, July, August and September (0 days).
Average daylight in December /
Average sunshine in December
Long Valley, 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: 5h and 18min
The month with the most sunshine is August (Average sunshine: 11h and 42min).
The months with the least sunshine are January and February (Average sunshine: 5h and 12min).
Average sunshine days in December
Long Valley, SD
- Average sunshine days in December: 21.1 days
The month with the most sunshine days is December (21.1 days).
The months with the least sunshine days are April and June (14.1 days).
Average UV index in December
Long Valley, SD
- Average UV index in December: 1
The month with the highest UV index is July (UV index 7).
The month with the lowest UV index is December (UV index 1).
Average cloud cover in December
Long Valley, SD
- Average cloud cover in December: 44
The month with the most cloud cover is January (Cloud cover 46).
The months with the least cloud cover are July and August (Cloud cover 18).
Average visibility in December
Long 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).
