December weather forecastHeyworth, IL
December
Weather in December
The first month of the winter, December, is also an icy month in Heyworth, Illinois, with an average temperature ranging between min 27°F (-2.8°C) and max 37°F (2.8°C).Temperature
The arrival of December signals a shift in temperature, down from a chilly 48.4°F (9.1°C) in November to a cold 37°F (2.8°C). An average low-temperature of 27°F (-2.8°C) is noted during the month of December.Humidity
In December, the average relative humidity in Heyworth is 80%.Rainfall
The month with the least rainfall is December, when the rain falls for 7.4 days and typically collects 0.67" (17mm) of precipitation.Snowfall
Months with snowfall are January through April, November and December. In Heyworth, in December, snow falls for 5.2 days, with typically accumulated 0.59" (15mm) of snow. In Heyworth, during the entire year, snow falls for 25.3 days and aggregates up to 5.28" (134mm) of snow.Daylight
With an average of 9h and 24min of daylight, December has the shortest days of the year.On the first day of December in Heyworth, sunrise is at 7:00 am and sunset at 4:30 pm. On the last day of the month, sunrise is at 7:18 am and sunset at 4:39 pm CST.
Sunshine
In Heyworth, the average sunshine in December is 4.4h.UV index
The months with the lowest UV index are January, February, November and December, with an average maximum UV index of 2. A UV Index reading of 2, and below, represents a low health risk from unsafe exposure to UV radiation for the average person.Note: In December, the maximum UV index of 2 translates into these guidelines:
Though extended exposure to the sun typically does not concern most people, it is crucial to always shield children, infants, and those with sensitive skin. Considering the Sun's intensity during midday, it's wise to minimize direct exposure. Sunglasses that guard against UVA and UVB rays are pivotal in minimizing sun-induced ocular damage. Be cautious! The UV radiation from the Sun can be magnified almost twofold by snow reflection.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in December
Heyworth, IL
- Average high temperature in December: 37°F
The warmest month (with the highest average high temperature) is July (81.1°F).
The month with the lowest average high temperature is January (31.3°F).
- Average low temperature in December: 27°F
The month with the highest average low temperature is July (64.9°F).
The coldest month (with the lowest average low temperature) is January (19.8°F).
Average pressure in December
Heyworth, IL
- Average pressure in December: 30.12"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
Heyworth, IL
- Average wind speed in December: 10.3mph
The windiest month (with the highest average wind speed) is January (10.9mph).
The calmest month (with the lowest average wind speed) is August (6.5mph).
Average humidity in December
Heyworth, 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
Heyworth, IL
- Average rainfall in December: 0.67"
The wettest month (with the highest rainfall) is May (1.69").
The driest month (with the least rainfall) is December (0.67").
Average rainfall days in December
Heyworth, IL
- Average rainfall days in December: 7.4 days
The month with the highest number of rainy days is May (15.8 days).
The month with the least rainy days is January (5.3 days).
Average snowfall in December
Heyworth, IL
- Average snowfall in December: 0.59"
The month with the highest snowfall is January (1.61").
The months with the least snowfall are May, June, July, August, September and October (0").
Average snowfall days in December
Heyworth, IL
- Average snowfall days in December: 5.2 days
The month with the highest number of snowfall days is January (8.5 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
Heyworth, IL
- Average daylight in December: 9h and 24min
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 24min).
- Average sunshine in December: 4h and 24min
The month with the most sunshine is June (Average sunshine: 10h and 6min).
The month with the least sunshine is January (Average sunshine: 3h and 54min).
Average sunshine days in December
Heyworth, IL
- Average sunshine days in December: 19.8 days
The month with the most sunshine days is November (20.5 days).
The month with the least sunshine days is May (11.7 days).
Average UV index in December
Heyworth, IL
- Average UV index in December: 2
The months with the highest UV index are June and July (UV index 6).
The months with the lowest UV index are January, February, November and December (UV index 2).
Average cloud cover in December
Heyworth, IL
- Average cloud cover in December: 54
The month with the most cloud cover is January (Cloud cover 59).
The months with the least cloud cover are August and September (Cloud cover 31).
Average visibility in December
Heyworth, 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).





