December weather forecastIona, SD
December
Weather in December
The first month of the winter, December, is still a freezing cold month in Iona, South Dakota, with temperature in the range of an average high of 29.1°F (-1.6°C) and an average low of 16.9°F (-8.4°C).Temperature
Iona sees a considerable decrease in average high-temperatures during December, falling from a chilly 45.5°F (7.5°C) in November to a subzero cold 29.1°F (-1.6°C). Iona, during the month of December, experiences an average low-temperature of 16.9°F (-8.4°C).Humidity
The average relative humidity in December is 82%.Rainfall
In December, in Iona, the rain falls for 3.9 days. Throughout December, 0.94" (24mm) of precipitation is accumulated. In Iona, during the entire year, the rain falls for 107.6 days and collects up to 17.83" (453mm) of precipitation.Snowfall
January through April, October through December are months with snowfall. In Iona, in December, snow falls for 9.6 days, with typically accumulated 3.07" (78mm) of snow. Throughout the year, there are 50.9 snowfall days, and 17.87" (454mm) 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 December, sunrise is at 7:51 am and sunset at 5:02 pm. On the last day of the month, sunrise is at 8:10 am and sunset at 5:11 pm CST.
Sunshine
In December, the average sunshine is 4.9h.UV index
In Iona, the average daily maximum UV index in December is 2. A UV Index of 2, and less, symbolizes a low health risk from unsafe exposure to UV radiation for the ordinary person.Note: In December, a regular UV index of 2 translates into these guidelines:
Children must always have sun protection, unlike most people, who can tolerate up to an hour in the sun without any burns. Sun exposure should be minimized, especially during midday, to avoid harmful UV radiation. Experience reduced UV exposure by about half when donning a wide-brim hat. Be alert! Nearly double the UV rays from the Sun can be reflected by snow.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in December
Iona, SD
- Average high temperature in December: 29.1°F
The warmest month (with the highest average high temperature) is July (88°F).
The month with the lowest average high temperature is January (26.1°F).
- Average low temperature in December: 16.9°F
The month with the highest average low temperature is July (66.2°F).
The coldest month (with the lowest average low temperature) is January (12.6°F).
Average pressure in December
Iona, SD
- Average pressure in December: 30.13"Hg
The month with the highest atmospheric pressure is January (30.16"Hg).
The month with the lowest atmospheric pressure is June (29.84"Hg).
Average wind speed in December
Iona, SD
- Average wind speed in December: 10mph
The windiest month (with the highest average wind speed) is April (11.3mph).
The calmest month (with the lowest average wind speed) is August (9.1mph).
Average humidity in December
Iona, SD
- Average humidity in December: 82%
The month with the highest relative humidity is January (86%).
The month with the lowest relative humidity is September (58%).
Average rainfall in December
Iona, SD
- Average rainfall in December: 0.94"
The wettest month (with the highest rainfall) is June (3.03").
The driest month (with the least rainfall) is November (0.55").
Average rainfall days in December
Iona, SD
- Average rainfall days in December: 3.9 days
The month with the highest number of rainy days is May (15.3 days).
The month with the least rainy days is February (3.3 days).
Average snowfall in December
Iona, SD
- Average snowfall in December: 3.07"
The month with the highest snowfall is February (3.66").
The months with the least snowfall are May, June, July, August and September (0").
Average snowfall days in December
Iona, SD
- Average snowfall days in December: 9.6 days
The months with the highest number of snowfall days are January and February (11.7 days).
The months with the least snowfall days are June, July, August and September (0 days).
Average daylight in December /
Average sunshine in December
Iona, 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 54min
The month with the most sunshine is July (Average sunshine: 11h and 24min).
The month with the least sunshine is January (Average sunshine: 4h and 42min).
Average sunshine days in December
Iona, SD
- Average sunshine days in December: 19.5 days
The month with the most sunshine days is November (20.7 days).
The month with the least sunshine days is April (11.8 days).
Average UV index in December
Iona, 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 February (UV index 1).
Average cloud cover in December
Iona, SD
- Average cloud cover in December: 47
The month with the most cloud cover is January (Cloud cover 49).
The month with the least cloud cover is August (Cloud cover 20).
Average visibility in December
Iona, SD
- Average visibility in December: 6mi
The months with the highest visibility are February, March, April, May, June, July, August, September, October, November and December (6mi).
The month with the lowest visibility is January (5mi).
