December weather forecastCuster, SD
December
Weather in December
December in Custer indicates the solid arrival of winter, a stark contrast to the transitional weather of November. The city starts decking in white, courtesy of frequent and extended spells of snowfall. Peak winter sets in, with daily temperature ranges seldom climbing above the freezing point. The days grow shorter, a prelude to the solstice, ushering in a new year. In the midst of the chill, a white Christmas is almost always guaranteed, enhancing the festive atmosphere of this holiday season.Temperature
In Custer, South Dakota, December records the lowest average temperatures, peaking at 29.8°F (-1.2°C) and reaching a low of 16.5°F (-8.6°C).Humidity
In December, the average relative humidity is 74%.Rainfall
In Custer, in December, during 6.3 rainfall days, 0.67" (17mm) of precipitation is typically accumulated. Throughout the year, in Custer, there are 135.4 rainfall days, and 20.39" (518mm) of precipitation is accumulated.Snowfall
Months with snowfall are January through May, September through December. In December, in Custer, it is snowing for 11.5 days. Throughout December, 4.57" (116mm) of snow is accumulated. Throughout the year, in Custer, there are 75.1 snowfall days, and 40.24" (1022mm) of snow is accumulated.Daylight
December has the shortest days of the year, with an average of 9h and 0min of daylight.On the first day of the month, sunrise is at 7:09 am and sunset at 4:18 pm. On the last day of December, sunrise is at 7:28 am and sunset at 4:27 pm MST.
Sunshine
In Custer, the average sunshine in December is 6.2h.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 unsafe exposure to UV radiation for ordinary individuals.Note: The maximum UV index of 2 during December leads to these instructions:
Most people can stay in the Sun for up to 1 hour without burning, apart from children that always must be protected from sun exposure. The intensity of the Sun's UV radiation during midday suggests reducing time spent outdoors. During bright days, sunglasses that offer UVA and UVB defense are recommended. Attention! Nearly twice the Sun's UV radiation can be reflected by snow.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in December
Custer, SD
- Average high temperature in December: 29.8°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 (29.8°F).
- Average low temperature in December: 16.5°F
The month with the highest average low temperature is July (60.4°F).
The coldest month (with the lowest average low temperature) is February (16.2°F).
Average pressure in December
Custer, SD
- Average pressure in December: 30.12"Hg
The month with the highest atmospheric pressure is January (30.13"Hg).
The month with the lowest atmospheric pressure is June (29.84"Hg).
Average wind speed in December
Custer, SD
- Average wind speed in December: 8.9mph
The windiest month (with the highest average wind speed) is April (9.5mph).
The calmest month (with the lowest average wind speed) is August (7mph).
Average humidity in December
Custer, SD
- Average humidity in December: 74%
The months with the highest relative humidity are January and February (77%).
The months with the lowest relative humidity are August and September (52%).
Average rainfall in December
Custer, SD
- Average rainfall in December: 0.67"
The wettest month (with the highest rainfall) is June (3.19").
The driest month (with the least rainfall) is January (0.47").
Average rainfall days in December
Custer, SD
- Average rainfall days in December: 6.3 days
The month with the highest number of rainy days is May (18.6 days).
The month with the least rainy days is November (4.5 days).
Average snowfall in December
Custer, SD
- Average snowfall in December: 4.57"
The month with the highest snowfall is April (7.24").
The months with the least snowfall are June, July and August (0").
Average snowfall days in December
Custer, SD
- Average snowfall days in December: 11.5 days
The month with the highest number of snowfall days is February (12.9 days).
The months with the least snowfall days are June, July and August (0 days).
Average daylight in December /
Average sunshine in December
Custer, 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: 6h and 12min
The month with the most sunshine is August (Average sunshine: 11h and 42min).
The month with the least sunshine is February (Average sunshine: 6h and 0min).
Average sunshine days in December
Custer, SD
- Average sunshine days in December: 18.1 days
The month with the most sunshine days is November (19.2 days).
The month with the least sunshine days is May (7.8 days).
Average UV index in December
Custer, SD
- 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
Custer, SD
- Average cloud cover in December: 34
The month with the most cloud cover is April (Cloud cover 38).
The month with the least cloud cover is August (Cloud cover 17).
Average visibility in December
Custer, 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).
