December weather forecastPark Forest, IL
December
Weather in December
The first month of the winter, December, is also an icy month in Park Forest, Illinois, with an average temperature fluctuating between 35.6°F (2°C) and 25.9°F (-3.4°C).Temperature
The arrival of December signals a shift in temperature, down from a frosty 46.9°F (8.3°C) in November to a cold 35.6°F (2°C). Throughout the month of December, Park Forest observes an average nighttime temperature of 25.9°F (-3.4°C).Humidity
In December, the average relative humidity is 81%.Rainfall
December is the month with the least rainfall. Rain falls for 7.9 days and accumulates 1.54" (39mm) of precipitation.Snowfall
Months with snowfall are January through April, October through December. In Park Forest, Illinois, in December, snow falls for 9.1 days, with typically accumulated 2.76" (70mm) of snow. In Park Forest, during the entire year, snow falls for 44.6 days and aggregates up to 16.46" (418mm) of snow.Daylight
December has the shortest days of the year, with an average of 9h and 12min of daylight.On the first day of the month, sunrise is at 6:58 am and sunset at 4:21 pm. On the last day of December, sunrise is at 7:16 am and sunset at 4:31 pm CST.
Sunshine
In December, the average sunshine is 4h.UV index
December is the month with the lowest UV index, with an average maximum UV index of 1. A UV Index reading of 2, and below, represents a low health risk from exposure to the Sun's UV radiation for ordinary individuals.Note: The daily high UV index of 1 in December translates into this advice:
In contrast to children, who must always be shielded from the sun, most people can tolerate up to an hour of sun exposure without any burns. Avoiding direct sun during mid-day hours can prevent harmful UV radiation exposure. Sun-protective clothing, a long-sleeved shirt and pants, a wide-brimmed hat, and UVA and UVB-blocking sunglasses are particularly helpful in blocking UV radiation's harmful effects. Be alert! Nearly double the UV rays from the Sun can be reflected by snow.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in December
Park Forest, IL
- Average high temperature in December: 35.6°F
The warmest month (with the highest average high temperature) is July (81.3°F).
The month with the lowest average high temperature is January (29.7°F).
- Average low temperature in December: 25.9°F
The month with the highest average low temperature is July (65.8°F).
The coldest month (with the lowest average low temperature) is January (18.9°F).
Average pressure in December
Park Forest, IL
- Average pressure in December: 30.1"Hg
The month with the highest atmospheric pressure is January (30.11"Hg).
The month with the lowest atmospheric pressure is June (29.92"Hg).
Average wind speed in December
Park Forest, IL
- Average wind speed in December: 9.5mph
The windiest month (with the highest average wind speed) is January (10.2mph).
The calmest month (with the lowest average wind speed) is August (6.3mph).
Average humidity in December
Park Forest, IL
- Average humidity in December: 81%
The months with the highest relative humidity are January and February (82%).
The month with the lowest relative humidity is October (73%).
Average rainfall in December
Park Forest, IL
- Average rainfall in December: 1.54"
The wettest month (with the highest rainfall) is May (4.17").
The driest month (with the least rainfall) is December (1.54").
Average rainfall days in December
Park Forest, IL
- Average rainfall days in December: 7.9 days
The month with the highest number of rainy days is July (17.6 days).
The month with the least rainy days is February (6.1 days).
Average snowfall in December
Park Forest, IL
- Average snowfall in December: 2.76"
The month with the highest snowfall is January (4.53").
The months with the least snowfall are May, June, July, August and September (0").
Average snowfall days in December
Park Forest, IL
- Average snowfall days in December: 9.1 days
The month with the highest number of snowfall days is January (12.6 days).
The months with the least snowfall days are June, July, August and September (0 days).
Average daylight in December /
Average sunshine in December
Park Forest, 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 month with the most sunshine is August (Average sunshine: 10h and 6min).
The month with the least sunshine is January (Average sunshine: 3h and 36min).
Average sunshine days in December
Park Forest, IL
- Average sunshine days in December: 15 days
The month with the most sunshine days is November (16.4 days).
The month with the least sunshine days is April (10.2 days).
Average UV index in December
Park Forest, IL
- Average UV index in December: 1
The months with the highest UV index are June and July (UV index 6).
The month with the lowest UV index is December (UV index 1).
Average cloud cover in December
Park Forest, IL
- Average cloud cover in December: 59
The month with the most cloud cover is January (Cloud cover 62).
The month with the least cloud cover is August (Cloud cover 30).
Average visibility in December
Park Forest, IL
- Average visibility in December: 6mi
The months with the highest visibility are February, March, April, May, June, July, August, September, October, November and December (6mi).
The month with the lowest visibility is January (5mi).





