December weather forecastWalnut, IL
December
Weather in December
December, the first month of the winter in Walnut, is also a wintry month, with an average temperature ranging between min 23.9°F (-4.5°C) and max 34°F (1.1°C).Temperature
Transition into December marks a drop in the average high-temperature, moving from a frosty 46.2°F (7.9°C) in November to an icy 34°F (1.1°C). In December, the average low-temperature is a freezing cold 23.9°F (-4.5°C).Humidity
The average relative humidity in December is 82%.Rainfall
In Walnut, in December, during 4.8 rainfall days, 0.63" (16mm) of precipitation is typically accumulated. In Walnut, during the entire year, the rain falls for 114.5 days and collects up to 12.72" (323mm) of precipitation.Snowfall
January through April, October through December are months with snowfall. In Walnut, during December, snow falls for 6.5 days and regularly aggregates up to 0.94" (24mm) of snow. Throughout the year, there are 31.5 snowfall days, and 5.2" (132mm) of snow is accumulated.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 7:06 am and sunset at 4:29 pm. On the last day of the month, sunrise is at 7:24 am and sunset at 4:38 pm CST.
Sunshine
The average sunshine in December is 4h.UV index
January and December, with an average maximum UV index of 1, are months with the lowest UV index. A UV Index value of 2, and less, symbolizes a minimal health hazard from unprotected exposure to Sun's UV rays for the ordinary person.Note: The UV index of 1 during December translates into the following guidance:
While many people can endure lengthy sun exposure, it remains imperative to safeguard babies, children, and fair-skinned individuals. During midday, the Sun's radiation is strongest, and it's advisable to reduce direct exposure. Sunglasses that guard against UVA and UVB rays are pivotal in minimizing sun-induced ocular damage. Be advised! The UV radiation from the Sun can be almost doubled due to the reflective properties of snow.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in December
Walnut, IL
- Average high temperature in December: 34°F
The warmest month (with the highest average high temperature) is July (80.2°F).
The month with the lowest average high temperature is January (27.5°F).
- Average low temperature in December: 23.9°F
The month with the highest average low temperature is July (64.2°F).
The coldest month (with the lowest average low temperature) is January (15.6°F).
Average pressure in December
Walnut, IL
- Average pressure in December: 30.1"Hg
The month with the highest atmospheric pressure is January (30.13"Hg).
The month with the lowest atmospheric pressure is June (29.91"Hg).
Average wind speed in December
Walnut, IL
- Average wind speed in December: 9.6mph
The windiest month (with the highest average wind speed) is April (10.5mph).
The calmest month (with the lowest average wind speed) is August (6.5mph).
Average humidity in December
Walnut, IL
- Average humidity in December: 82%
The month with the highest relative humidity is July (85%).
The month with the lowest relative humidity is October (73%).
Average rainfall in December
Walnut, IL
- Average rainfall in December: 0.63"
The wettest month (with the highest rainfall) is May (2.01").
The driest month (with the least rainfall) is January (0.55").
Average rainfall days in December
Walnut, IL
- Average rainfall days in December: 4.8 days
The month with the highest number of rainy days is May (15.3 days).
The month with the least rainy days is January (3.8 days).
Average snowfall in December
Walnut, IL
- Average snowfall in December: 0.94"
The month with the highest snowfall is January (1.57").
The months with the least snowfall are May, June, July, August and September (0").
Average snowfall days in December
Walnut, IL
- Average snowfall days in December: 6.5 days
The month with the highest number of snowfall days is January (10.1 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
Walnut, IL
- Average daylight in December: 9h and 12min
The month with the longest days is June (Average daylight: 15h and 6min).
The month with the shortest days is December (Average daylight: 9h and 12min).
- Average sunshine in December: 4h and 0min
The months with the most sunshine are June, July and August (Average sunshine: 9h and 36min).
The month with the least sunshine is January (Average sunshine: 3h and 42min).
Average sunshine days in December
Walnut, IL
- Average sunshine days in December: 20.8 days
The month with the most sunshine days is December (20.8 days).
The month with the least sunshine days is June (13.5 days).
Average UV index in December
Walnut, 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
Walnut, IL
- Average cloud cover in December: 57
The month with the most cloud cover is January (Cloud cover 60).
The month with the least cloud cover is September (Cloud cover 32).
Average visibility in December
Walnut, 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).





