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
The shift to December brings a decrease in the average high-temperature, falling from a chilly 45.1°F (7.3°C) in November to a wintry 32.7°F (0.4°C). In the month of December, the nighttime temperature dips to a steady average of 22.5°F (-5.3°C).Humidity
In Savanna, the average relative humidity in December is 82%.Rainfall
In Savanna, in December, it is raining for 8 days, with typically 1.54" (39mm) of accumulated precipitation. Throughout the year, there are 149.3 rainfall days, and 29.76" (756mm) of precipitation is accumulated.Snowfall
Months with snowfall are January through May, October through December. In December, it is snowing for 8.7 days. Throughout December, 2.56" (65mm) of snow is accumulated. In Savanna, during the entire year, snow falls for 41.2 days and aggregates up to 16.73" (425mm) of snow.Daylight
The month with the shortest days is December, with an average of 9h and 12min of daylight.On the first day of December, sunrise is at 7:10 am and sunset at 4:29 pm. On the last day of the month, sunrise is at 7:28 am and sunset at 4:39 pm CST.
Sunshine
In December, the average sunshine is 4.1h.UV index
The months with the lowest UV index are January and December, with an average maximum UV index of 1. A UV Index of 2, and less, symbolizes a low health risk from unsafe exposure to UV radiation for ordinary individuals.Note: In December, the UV index of 1 transforms into the following advice:
Extended sun exposure is not an issue for the majority. Children, infants, and fair-skinned individuals always need to be protected. When the Sun's UV radiation is most intense during midday, it's best to find shade and limit exposure. For excellent sun protection for the eyes, ears, face, and neck, consider a wide-brim hat. Watch out! The Sun's UV radiation can be nearly magnified twofold due to snow reflection.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
How cold is December?
What is the average humidity in December?
How much does it rain in December?
How many days does it snow in December?
What is the month with the shortest days in Savanna?
What is the average length of the day in December?
When is the sunrise / sunset in December?
How many hours of sunshine does Savanna have in December?
When is the lowest UV index?
What is the UV index reading in December?
Average temperature in December
Savanna, IL
- Average high temperature in December: 32.7°F
The warmest month (with the highest average high temperature) is July (80.1°F).
The month with the lowest average high temperature is January (26.1°F).
- Average low temperature in December: 22.5°F
The month with the highest average low temperature is July (63.5°F).
The coldest month (with the lowest average low temperature) is January (13.5°F).
Average pressure in December
Savanna, IL
- Average pressure in December: 30.1"Hg
The month with the highest atmospheric pressure is January (30.12"Hg).
The month with the lowest atmospheric pressure is June (29.91"Hg).
Average wind speed in December
Savanna, IL
- Average wind speed in December: 9.4mph
The windiest month (with the highest average wind speed) is April (10.4mph).
The calmest month (with the lowest average wind speed) is August (6.5mph).
Average humidity in December
Savanna, IL
- Average humidity in December: 82%
The month with the highest relative humidity is January (86%).
The month with the lowest relative humidity is October (74%).
Average rainfall in December
Savanna, IL
- Average rainfall in December: 1.54"
The wettest month (with the highest rainfall) is May (4.09").
The driest month (with the least rainfall) is February (1.38").
Average rainfall days in December
Savanna, IL
- Average rainfall days in December: 8 days
The month with the highest number of rainy days is May (18.5 days).
The month with the least rainy days is February (4.4 days).
Average snowfall in December
Savanna, IL
- Average snowfall in December: 2.56"
The month with the highest snowfall is January (5.12").
The months with the least snowfall are June, July, August and September (0").
Average snowfall days in December
Savanna, IL
- Average snowfall days in December: 8.7 days
The month with the highest number of snowfall days is January (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
Savanna, IL
- Average daylight in December: 9h and 1min
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: 4h and 1min
The month with the most sunshine is July (Average sunshine: 9h and 48min).
The month with the least sunshine is January (Average sunshine: 3h and 42min).
Average sunshine days in December
Savanna, IL
- Average sunshine days in December: 16.5 days
The month with the most sunshine days is November (17.8 days).
The month with the least sunshine days is June (9.6 days).
Average UV index in December
Savanna, IL
- Average UV index in December: 1
The month with the highest UV index is July (UV index 6).
The months with the lowest UV index are January and December (UV index 1).
Average cloud cover in December
Savanna, IL
- Average cloud cover in December: 58
The month with the most cloud cover is January (Cloud cover 61).
The month with the least cloud cover is September (Cloud cover 32).
Average visibility in December
Savanna, IL
- Average visibility in December: 6mi
The months with the highest visibility are February, March, April, May, June, September, October, November and December (6mi).
The months with the lowest visibility are January, July and August (5mi).
Savanna, Illinois, USA
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