December weather forecastShirley, IL
December
Weather in December
December, the first month of the winter in Shirley, is still a cold month, with an average temperature varying between 36.5°F (2.5°C) and 26.2°F (-3.2°C).Temperature
With the onset of December, Shirley's average high-temperature adjusts, receding from November's chilly 47.7°F (8.7°C) to a wintry 36.5°F (2.5°C). In Shirley, the expected average low-temperature for December is a subzero cold 26.2°F (-3.2°C).Humidity
In Shirley, Illinois, the average relative humidity in December is 80%.Rainfall
In December, the rain falls for 7.1 days. Throughout December, 1.22" (31mm) of precipitation is accumulated. Throughout the year, in Shirley, there are 140.6 rainfall days, and 22.44" (570mm) of precipitation is accumulated.Snowfall
Months with snowfall in Shirley are January through April, October through December. In Shirley, Illinois, in December, snow falls for 8 days, with typically accumulated 1.65" (42mm) of snow. Throughout the year, in Shirley, there are 35.4 snowfall days, and 9.45" (240mm) of snow is accumulated.Daylight
The month with the shortest days is December, with an average of 9h and 18min of daylight.On the first day of the month, sunrise is at 7:00 am and sunset at 4:30 pm. On the last day of December, sunrise is at 7:19 am and sunset at 4:39 pm CST.
Sunshine
In Shirley, the average sunshine in December is 4.1h.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 vulnerability from unprotected exposure to Sun's UV rays for average individuals.Note: The maximum UV index of 2 during December translates into these guidelines:
While many people can endure lengthy sun exposure, it remains imperative to safeguard babies, children, and fair-skinned individuals. Midday is when the Sun's radiation is strongest; avoid prolonged exposure during this time. Experience reduced UV exposure by about half when donning a wide-brim hat. Be watchful! The reflection of snow can enhance the intensity of the Sun's UV radiation nearly double.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in December
Shirley, IL
- Average high temperature in December: 36.5°F
The warmest month (with the highest average high temperature) is July (80.8°F).
The month with the lowest average high temperature is January (30.7°F).
- Average low temperature in December: 26.2°F
The month with the highest average low temperature is July (64.6°F).
The coldest month (with the lowest average low temperature) is January (18.9°F).
Average pressure in December
Shirley, IL
- Average pressure in December: 30.11"Hg
The month with the highest atmospheric pressure is January (30.14"Hg).
The month with the lowest atmospheric pressure is June (29.92"Hg).
Average wind speed in December
Shirley, IL
- Average wind speed in December: 10.5mph
The windiest month (with the highest average wind speed) is January (11.1mph).
The calmest month (with the lowest average wind speed) is August (6.6mph).
Average humidity in December
Shirley, IL
- Average humidity in December: 80%
The month with the highest relative humidity is July (85%).
The month with the lowest relative humidity is October (71%).
Average rainfall in December
Shirley, IL
- Average rainfall in December: 1.22"
The wettest month (with the highest rainfall) is May (2.99").
The driest month (with the least rainfall) is January (1.18").
Average rainfall days in December
Shirley, IL
- Average rainfall days in December: 7.1 days
The month with the highest number of rainy days is July (17.8 days).
The month with the least rainy days is February (5.3 days).
Average snowfall in December
Shirley, IL
- Average snowfall in December: 1.65"
The month with the highest snowfall is January (2.44").
The months with the least snowfall are May, June, July, August and September (0").
Average snowfall days in December
Shirley, IL
- Average snowfall days in December: 8 days
The month with the highest number of snowfall days is January (11.5 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
Shirley, IL
- Average daylight in December: 9h and 18min
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 18min).
- Average sunshine in December: 4h and 6min
The month with the most sunshine is June (Average sunshine: 9h and 42min).
The month with the least sunshine is January (Average sunshine: 3h and 36min).
Average sunshine days in December
Shirley, IL
- Average sunshine days in December: 16.6 days
The month with the most sunshine days is November (18.4 days).
The month with the least sunshine days is July (9.7 days).
Average UV index in December
Shirley, 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
Shirley, IL
- Average cloud cover in December: 56
The month with the most cloud cover is January (Cloud cover 61).
The month with the least cloud cover is September (Cloud cover 33).
Average visibility in December
Shirley, 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).





