December weather forecastPiasa, IL
December
Weather in December
The first month of the winter, December, is also an icy month in Piasa, Illinois, with temperature in the range of an average low of 29.3°F (-1.5°C) and an average high of 40.6°F (4.8°C).Temperature
The beginning of December involves a decrease in the average high-temperature, transitioning from a fresh 51.6°F (10.9°C) in November to an icy 40.6°F (4.8°C). In Piasa, an average low-temperature of 29.3°F (-1.5°C) is recorded during December nights.Humidity
In Piasa, the average relative humidity in December is 77%.Rainfall
In Piasa, during December, the rain falls for 8.1 days and regularly aggregates up to 1.61" (41mm) of precipitation. Throughout the year, there are 141.9 rainfall days, and 27.36" (695mm) of precipitation is accumulated.Snowfall
Months with snowfall are January through March, November and December. In Piasa, during December, snow falls for 3.9 days and regularly aggregates up to 1.73" (44mm) of snow. In Piasa, during the entire year, snow falls for 19.8 days and aggregates up to 7.91" (201mm) 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 7:01 am and sunset at 4:38 pm. On the last day of December, sunrise is at 7:19 am and sunset at 4:48 pm CST.
Sunshine
In Piasa, the average sunshine in December is 4.9h.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 reading of 2, and below, represents a low health risk from exposure to the Sun's UV rays for the average person.Note: In December, a daily UV index of 2 turns into the following recommendations:
Prolonged sun exposure should always be prevented in babies, children, and those with sensitive skin. Direct Sun exposure should be minimized especially during midday when radiation is most intense. Experience reduced UV exposure by about half when donning a wide-brim hat. Be aware! The reflective nature of snow can magnify the Sun's UV radiation almost twofold.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in December
Piasa, IL
- Average high temperature in December: 40.6°F
The warmest month (with the highest average high temperature) is July (84.6°F).
The month with the lowest average high temperature is January (35.8°F).
- Average low temperature in December: 29.3°F
The month with the highest average low temperature is July (67.5°F).
The coldest month (with the lowest average low temperature) is January (22.6°F).
Average pressure in December
Piasa, IL
- Average pressure in December: 30.13"Hg
The month with the highest atmospheric pressure is January (30.15"Hg).
The month with the lowest atmospheric pressure is June (29.92"Hg).
Average wind speed in December
Piasa, IL
- Average wind speed in December: 9.1mph
The windiest month (with the highest average wind speed) is January (9.8mph).
The calmest months (with the lowest average wind speed) are July and August (5.8mph).
Average humidity in December
Piasa, IL
- Average humidity in December: 77%
The month with the highest relative humidity is July (81%).
The month with the lowest relative humidity is October (71%).
Average rainfall in December
Piasa, IL
- Average rainfall in December: 1.61"
The wettest month (with the highest rainfall) is June (3.35").
The driest month (with the least rainfall) is January (1.46").
Average rainfall days in December
Piasa, IL
- Average rainfall days in December: 8.1 days
The month with the highest number of rainy days is May (16.7 days).
The month with the least rainy days is January (6.5 days).
Average snowfall in December
Piasa, IL
- Average snowfall in December: 1.73"
The month with the highest snowfall is February (2.48").
The months with the least snowfall are April, May, June, July, August, September and October (0").
Average snowfall days in December
Piasa, IL
- Average snowfall days in December: 3.9 days
The month with the highest number of snowfall days is January (6.2 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
Piasa, IL
- Average daylight in December: 9h and 30min
The month with the longest days is June (Average daylight: 14h and 54min).
The month with the shortest days is December (Average daylight: 9h and 30min).
- Average sunshine in December: 4h and 54min
The month with the most sunshine is June (Average sunshine: 10h and 18min).
The month with the least sunshine is January (Average sunshine: 4h and 24min).
Average sunshine days in December
Piasa, IL
- Average sunshine days in December: 19.3 days
The month with the most sunshine days is January (19.5 days).
The month with the least sunshine days is July (12.1 days).
Average UV index in December
Piasa, IL
- Average UV index in December: 2
The months with the highest UV index are May, 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
Piasa, IL
- Average cloud cover in December: 49
The month with the most cloud cover is January (Cloud cover 52).
The months with the least cloud cover are August and September (Cloud cover 29).
Average visibility in December
Piasa, 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).
