Contents
- Weather in December
- Frequently asked questions
- Average temperature in December
- Average pressure in December
- Average wind speed in December
- Average humidity in December
- Average rainfall in December
- Average rainfall days in December
- Average snowfall in December
- Average snowfall days in December
- Average daylight in December
- Average sunshine in December
- Average sunshine days in December
- Average UV index in December
- Average cloud cover in December
- Average visibility in December
Weather in December
Temperature
A shift in the average high-temperature occurs in December, reducing from a cool 50°F (10°C) in November to a wintry 38.7°F (3.7°C). December nights are marked by an average temperature drop to a freezing cold 28.2°F (-2.1°C).Humidity
In Riverton, the average relative humidity in December is 78%.Rainfall
The month with the least rainfall is December, when the rain falls for 6.6 days and typically collects 0.83" (21mm) of precipitation.Snowfall
Months with snowfall in Riverton are January through April, November and December. In December, it is snowing for 4.8 days. Throughout December, 0.59" (15mm) of snow is accumulated. In Riverton, during the entire year, snow falls for 24.5 days and aggregates up to 5.51" (140mm) of snow.Daylight
The month with the shortest days is December, with an average of 9h and 24min of daylight.On the first day of December, sunrise is at 7:01 am and sunset at 4:33 pm. On the last day of the month, sunrise is at 7:19 am and sunset at 4:43 pm CST.
Sunshine
The average sunshine in December is 4.7h.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 low threat to health from exposure to the Sun's UV rays for average individuals.Note: A daily high UV index of 2 in December leads to these guidelines:
Most individuals can handle sun exposure for up to an hour without burning, but children must always be shielded from sun exposure. Sun exposure should be minimized, especially during midday, to avoid harmful UV radiation. To best shield against UV radiation, choose sun-safe garments and dependable sunglasses. Take warning! The intensity of the Sun's UV radiation can be nearly amplified twice due to snow reflection.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Is it cold during December?
What is the average humidity in December?
What is the driest month?
How many days does it rain in December?
How many days does it snow in December?
What is the month with the shortest days?
What is the average length of the day in December in Riverton?
When is the sunrise / sunset in December?
How long on average sun shines in December?
What is the month with the lowest UV index?
How high is the UV index in December?
Average temperature in December
Riverton, IL
- Average high temperature in December: 38.7°F
The warmest month (with the highest average high temperature) is July (82.8°F).
The month with the lowest average high temperature is January (33.1°F).
- Average low temperature in December: 28.2°F
The month with the highest average low temperature is July (66°F).
The coldest month (with the lowest average low temperature) is January (20.8°F).
Average pressure in December
Riverton, IL
- Average pressure in December: 30.12"Hg
The month with the highest atmospheric pressure is January (30.15"Hg).
The month with the lowest atmospheric pressure is June (29.91"Hg).
Average wind speed in December
Riverton, IL
- Average wind speed in December: 9.8mph
The windiest months (with the highest average wind speed) are January and April (10.4mph).
The calmest months (with the lowest average wind speed) are July and August (6.2mph).
Average humidity in December
Riverton, IL
- Average humidity in December: 78%
The month with the highest relative humidity is July (84%).
The month with the lowest relative humidity is October (70%).
Average rainfall in December
Riverton, IL
- Average rainfall in December: 0.83"
The wettest month (with the highest rainfall) is June (2.36").
The driest month (with the least rainfall) is December (0.83").
Average rainfall days in December
Riverton, IL
- Average rainfall days in December: 6.6 days
The month with the highest number of rainy days is May (17 days).
The month with the least rainy days is February (5.7 days).
Average snowfall in December
Riverton, IL
- Average snowfall in December: 0.59"
The month with the highest snowfall is January (1.81").
The months with the least snowfall are May, June, July, August, September and October (0").
Average snowfall days in December
Riverton, IL
- Average snowfall days in December: 4.8 days
The month with the highest number of snowfall days is January (8 days).
The months with the least snowfall days are May, June, July, August and September (0 days).
Average daylight in December /
Average sunshine in December
Riverton, IL
- Average daylight in December: 9h and 2min
The month with the longest days is June (Average daylight: 15h and 0min).
The month with the shortest days is December (Average daylight: 9h and 24min).
- Average sunshine in December: 4h and 4min
The month with the most sunshine is June (Average sunshine: 10h and 24min).
The month with the least sunshine is January (Average sunshine: 4h and 6min).
Average sunshine days in December
Riverton, IL
- Average sunshine days in December: 20.5 days
The month with the most sunshine days is December (20.5 days).
The month with the least sunshine days is May (11.5 days).
Average UV index in December
Riverton, IL
- 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
Riverton, IL
- Average cloud cover in December: 51
The month with the most cloud cover is January (Cloud cover 55).
The months with the least cloud cover are June, August and September (Cloud cover 30).
Average visibility in December
Riverton, IL
- Average visibility in December: 6mi
The months with the highest visibility are January, February, March, April, May, June, September, October, November and December (6mi).
The months with the lowest visibility are July and August (5mi).
Riverton, Illinois, USA
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