December weather forecastRiver Sioux, IA
December
Weather in December
The first month of the winter, December, is also an icy month in River Sioux, Iowa, with an average temperature fluctuating between 21°F (-6.1°C) and 32.9°F (0.5°C).Temperature
River Sioux in December experiences a marked decrease in the average high-temperature, descending from November's chilly 47.5°F (8.6°C) to a wintry 32.9°F (0.5°C). The average temperature during December nights is registered at a freezing cold 21°F (-6.1°C).Humidity
The average relative humidity in December is 79%.Rainfall
In River Sioux, during December, the rain falls for 4.6 days and regularly aggregates up to 1.42" (36mm) of precipitation. In River Sioux, during the entire year, the rain falls for 125.1 days and collects up to 22.64" (575mm) of precipitation.Snowfall
Months with snowfall in River Sioux are January through May, October through December. In River Sioux, in December, snow falls for 6.8 days, with typically accumulated 2.17" (55mm) of snow. In River Sioux, during the entire year, snow falls for 32.8 days and aggregates up to 11.97" (304mm) of snow.Daylight
December has the shortest days of the year, with an average of 9h and 12min of daylight.On the first day of the month, sunrise is at 7:32 am and sunset at 4:54 pm. On the last day of December, sunrise is at 7:51 am and sunset at 5:03 pm CST.
Sunshine
In December, the average sunshine is 5h.UV index
The months with the lowest UV index are January, February, November and December, with an average maximum UV index of 2. A UV Index estimate of 2, and below, represents a minimal health vulnerability from exposure to the Sun's UV radiation for the average person.Note: A typical high UV index of 2 in December suggests the following recommendations:
It is important to always shield children, babies, and individuals with sensitive skin from prolonged exposure to the sun. The solar radiation is most powerful near the mid-day, so the exposure to the direct Sun should be reduced accordingly. Opt for tightly woven and loose clothing to enhance protection from the Sun. Take heed! The reflection of snow can intensify the Sun's UV radiation nearly double.
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Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in December
River Sioux, IA
- Average high temperature in December: 32.9°F
The warmest month (with the highest average high temperature) is July (84.4°F).
The month with the lowest average high temperature is January (28.8°F).
- Average low temperature in December: 21°F
The month with the highest average low temperature is July (65.5°F).
The coldest month (with the lowest average low temperature) is January (15.3°F).
Average pressure in December
River Sioux, IA
- 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 (29.86"Hg).
Average wind speed in December
River Sioux, IA
- Average wind speed in December: 10mph
The windiest month (with the highest average wind speed) is April (10.8mph).
The calmest month (with the lowest average wind speed) is July (7.2mph).
Average humidity in December
River Sioux, IA
- Average humidity in December: 79%
The month with the highest relative humidity is January (81%).
The month with the lowest relative humidity is October (66%).
Average rainfall in December
River Sioux, IA
- Average rainfall in December: 1.42"
The wettest month (with the highest rainfall) is May (3.5").
The driest month (with the least rainfall) is January (0.71").
Average rainfall days in December
River Sioux, IA
- Average rainfall days in December: 4.6 days
The month with the highest number of rainy days is June (16.8 days).
The month with the least rainy days is February (3.3 days).
Average snowfall in December
River Sioux, IA
- Average snowfall in December: 2.17"
The month with the highest snowfall is January (2.8").
The months with the least snowfall are June, July, August and September (0").
Average snowfall days in December
River Sioux, IA
- Average snowfall days in December: 6.8 days
The month with the highest number of snowfall days is January (9.4 days).
The months with the least snowfall days are June, July, August and September (0 days).
Average daylight in December /
Average sunshine in December
River Sioux, IA
- Average daylight in December: 9h and 12min
The month with the longest days is June (Average daylight: 15h and 12min).
The month with the shortest days is December (Average daylight: 9h and 12min).
- Average sunshine in December: 5h and 0min
The month with the most sunshine is July (Average sunshine: 10h and 42min).
The month with the least sunshine is January (Average sunshine: 4h and 42min).
Average sunshine days in December
River Sioux, IA
- Average sunshine days in December: 20.2 days
The month with the most sunshine days is November (20.7 days).
The month with the least sunshine days is June (11.3 days).
Average UV index in December
River Sioux, IA
- Average UV index in December: 2
The months with the highest UV index are June, July and August (UV index 6).
The months with the lowest UV index are January, February, November and December (UV index 2).
Average cloud cover in December
River Sioux, IA
- Average cloud cover in December: 45
The month with the most cloud cover is January (Cloud cover 49).
The month with the least cloud cover is July (Cloud cover 25).
Average visibility in December
River Sioux, IA
- 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).
