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 subtle decrease in the average high-temperature marks December, falling from November's fresh 52.2°F (11.2°C) to a cold 41.9°F (5.5°C). Throughout the month of December, Sumner observes an average nighttime temperature of 30.9°F (-0.6°C).Humidity
In Sumner, the average relative humidity in December is 79%.Rainfall
In December, in Sumner, the rain falls for 10.5 days. Throughout December, 2.6" (66mm) of precipitation is accumulated. Throughout the year, there are 160.3 rainfall days, and 34.33" (872mm) of precipitation is accumulated.Snowfall
January through April, November and December are months with snowfall. In December, it is snowing for 4.3 days. Throughout December, 1.26" (32mm) of snow is accumulated. In Sumner, Illinois, during the entire year, snow falls for 21.7 days and aggregates up to 5.87" (149mm) of snow.Daylight
The month with the shortest days is December, with an average of 9h and 30min of daylight.On the first day of the month, sunrise is at 6:51 am and sunset at 4:30 pm. On the last day of December, sunrise is at 7:09 am and sunset at 4:40 pm CST.
Sunshine
In December, the average sunshine is 4.5h.UV index
January, February, November and December, with an average maximum UV index of 2, are months with the lowest UV index. A UV Index estimate of 2, and below, represents a minimal health hazard from unprotected exposure to Sun's UV rays for average individuals.Note: In December, an average UV index of 2 transforms into the following instructions:
Children, babies, and those with sensitive skin should always be shielded from long periods of sun exposure. Stay safe from the Sun's strongest UV rays by limiting exposure during midday. Employ a hat with a wide brim for robust protection, cutting UV exposure by half. Remember to consider! The UV radiation from the Sun can be intensified nearly twice by the reflection of snow.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Is it cold in Sumner during December?
What is the average humidity in December in Sumner?
How much does it rain in Sumner in December?
How much does it snow in Sumner in December?
What is the month with the shortest days in Sumner?
What is the average length of the day in December in Sumner?
When is the sunrise / sunset in December in Sumner?
How many hours of sunshine does Sumner have in December?
When is the lowest UV index in Sumner?
How high is the UV index in December in Sumner?
Average temperature in December
Sumner, IL
- Average high temperature in December: 41.9°F
The warmest month (with the highest average high temperature) is July (84°F).
The month with the lowest average high temperature is January (36.7°F).
- Average low temperature in December: 30.9°F
The month with the highest average low temperature is July (67.3°F).
The coldest month (with the lowest average low temperature) is January (24.4°F).
Average pressure in December
Sumner, IL
- Average pressure in December: 30.14"Hg
The month with the highest atmospheric pressure is January (30.16"Hg).
The month with the lowest atmospheric pressure is June (29.94"Hg).
Average wind speed in December
Sumner, IL
- Average wind speed in December: 9.3mph
The windiest month (with the highest average wind speed) is February (10.1mph).
The calmest month (with the lowest average wind speed) is July (5.8mph).
Average humidity in December
Sumner, IL
- Average humidity in December: 79%
The month with the highest relative humidity is July (81%).
The month with the lowest relative humidity is October (70%).
Average rainfall in December
Sumner, IL
- Average rainfall in December: 2.6"
The wettest month (with the highest rainfall) is April (4.69").
The driest month (with the least rainfall) is September (1.93").
Average rainfall days in December
Sumner, IL
- Average rainfall days in December: 10.5 days
The month with the highest number of rainy days is May (19.6 days).
The month with the least rainy days is February (9.4 days).
Average snowfall in December
Sumner, IL
- Average snowfall in December: 1.26"
The month with the highest snowfall is January (1.69").
The months with the least snowfall are May, June, July, August, September and October (0").
Average snowfall days in December
Sumner, IL
- Average snowfall days in December: 4.3 days
The month with the highest number of snowfall days is January (6.8 days).
The months with the least snowfall days are May, June, July, August, September and October (0 days).
Average daylight in December /
Average sunshine in December
Sumner, IL
- Average daylight in December: 9h and 3min
The month with the longest days is June (Average daylight: 14h and 48min).
The month with the shortest days is December (Average daylight: 9h and 30min).
- Average sunshine in December: 4h and 3min
The month with the most sunshine is June (Average sunshine: 10h and 36min).
The month with the least sunshine is January (Average sunshine: 4h and 24min).
Average sunshine days in December
Sumner, IL
- Average sunshine days in December: 16 days
The month with the most sunshine days is October (18 days).
The month with the least sunshine days is May (9.4 days).
Average UV index in December
Sumner, 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
Sumner, IL
- Average cloud cover in December: 51
The month with the most cloud cover is January (Cloud cover 53).
The month with the least cloud cover is August (Cloud cover 27).
Average visibility in December
Sumner, IL
- 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).
Sumner, Illinois, USA
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