December weather forecastOrtley, SD
December
Weather in December
The first month of the winter, December, is also a subzero cold month in Ortley, South Dakota, with temperature in the range of an average low of 11.5°F (-11.4°C) and an average high of 23.2°F (-4.9°C).Temperature
A decrease in the average high-temperature marks December, falling from November's wintry 38.8°F (3.8°C) to a subzero cold 23.2°F (-4.9°C). In December, the temperature drops to an average of 11.5°F (-11.4°C) at night.Humidity
In December, the average relative humidity in Ortley, South Dakota, is 88%.Rainfall
In Ortley, in December, it is raining for 4.1 days, with typically 0.98" (25mm) of accumulated precipitation. In Ortley, South Dakota, during the entire year, the rain falls for 112.9 days and collects up to 22.09" (561mm) of precipitation.Snowfall
January through May, October through December are months with snowfall. December is the month with the most snowfall in Ortley. Snow falls for 14.6 days and accumulates 4.53" (115mm) of snow.Daylight
With an average of 8h and 48min of daylight, December has the shortest days of the year.On the first day of December in Ortley, sunrise is at 7:48 am and sunset at 4:47 pm. On the last day of the month, sunrise is at 8:08 am and sunset at 4:56 pm CST.
Sunshine
In Ortley, the average sunshine in December is 3.6h.UV index
January, November and December, with an average maximum UV index of 1, are months with the lowest UV index. A UV Index value of 2, and less, symbolizes a minimal health vulnerability from unprotected exposure to Sun's UV rays for the ordinary person.Note: A maximum high daily UV index of 1 during December translates into the following directions:
People with sensitive skin, children, and babies should always be protected from prolonged sun exposure. Given the potency of the midday Sun's UV radiation, one should avoid prolonged exposure. For excellent sun protection for the eyes, ears, face, and neck, consider a wide-brim hat. Note well! The intensity of the Sun's UV rays can be nearly doubled by snow reflection.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in December
Ortley, SD
- Average high temperature in December: 23.2°F
The warmest month (with the highest average high temperature) is July (81°F).
The month with the lowest average high temperature is January (18.9°F).
- Average low temperature in December: 11.5°F
The month with the highest average low temperature is July (61.3°F).
The coldest month (with the lowest average low temperature) is January (5°F).
Average pressure in December
Ortley, SD
- Average pressure in December: 30.13"Hg
The month with the highest atmospheric pressure is February (30.17"Hg).
The month with the lowest atmospheric pressure is June (29.85"Hg).
Average wind speed in December
Ortley, SD
- Average wind speed in December: 11mph
The windiest month (with the highest average wind speed) is April (11.7mph).
The calmest month (with the lowest average wind speed) is July (8.7mph).
Average humidity in December
Ortley, SD
- Average humidity in December: 88%
The month with the highest relative humidity is January (91%).
The month with the lowest relative humidity is September (66%).
Average rainfall in December
Ortley, SD
- Average rainfall in December: 0.98"
The wettest month (with the highest rainfall) is July (3.58").
The driest month (with the least rainfall) is November (0.63").
Average rainfall days in December
Ortley, SD
- Average rainfall days in December: 4.1 days
The month with the highest number of rainy days is June (17.9 days).
The month with the least rainy days is February (2.3 days).
Average snowfall in December
Ortley, SD
- Average snowfall in December: 4.53"
The month with the highest snowfall is December (4.53").
The months with the least snowfall are June, July, August and September (0").
Average snowfall days in December
Ortley, SD
- Average snowfall days in December: 14.6 days
The month with the highest number of snowfall days is January (15.1 days).
The months with the least snowfall days are June, July, August and September (0 days).
Average daylight in December /
Average sunshine in December
Ortley, SD
- Average daylight in December: 8h and 48min
The month with the longest days is June (Average daylight: 15h and 36min).
The month with the shortest days is December (Average daylight: 8h and 48min).
- Average sunshine in December: 3h and 36min
The month with the most sunshine is July (Average sunshine: 10h and 42min).
The month with the least sunshine is January (Average sunshine: 3h and 12min).
Average sunshine days in December
Ortley, SD
- Average sunshine days in December: 15.2 days
The month with the most sunshine days is November (19.5 days).
The month with the least sunshine days is June (10.4 days).
Average UV index in December
Ortley, SD
- Average UV index in December: 1
The months with the highest UV index are June and July (UV index 6).
The months with the lowest UV index are January, November and December (UV index 1).
Average cloud cover in December
Ortley, SD
- Average cloud cover in December: 62
The month with the most cloud cover is January (Cloud cover 66).
The months with the least cloud cover are July and August (Cloud cover 27).
Average visibility in December
Ortley, SD
- Average visibility in December: 5mi
The months with the highest visibility are April, May, June, July, August, September, October and November (6mi).
The months with the lowest visibility are January, February, March and December (5mi).
