Contents
- Weather in December
- Frequently asked questions
- Average temperature in December
- Average pressure in December
- Average wind speed in December
- Average humidity in December
- Average rainfall in December
- Average rainfall days in December
- Average snowfall in December
- Average snowfall days in December
- Average daylight in December
- Average sunshine in December
- Average sunshine days in December
- Average UV index in December
- Average cloud cover in December
- Average visibility in December
Weather in December
Temperature
With the beginning of December, the average high-temperature shows a decrease, transitioning from a frosty 47.5°F (8.6°C) in November to a cold 36.3°F (2.4°C). In Irwin, an average low-temperature of 26.1°F (-3.3°C) is recorded during December nights.Humidity
In Irwin, the average relative humidity in December is 81%.Rainfall
In Irwin, in December, during 7.3 rainfall days, 1.14" (29mm) of precipitation is typically accumulated. Throughout the year, in Irwin, there are 142.1 rainfall days, and 22.56" (573mm) of precipitation is accumulated.Snowfall
Months with snowfall in Irwin are January through April, October through December. In December, it is snowing for 8.5 days. Throughout December, 1.54" (39mm) of snow is accumulated. In Irwin, during the entire year, snow falls for 39 days and aggregates up to 9.02" (229mm) of snow.Daylight
The month with the shortest days in Irwin is December, with an average of 9h and 18min of daylight.On the first day of December, sunrise is at 6:58 am and sunset at 4:24 pm. On the last day of the month, sunrise is at 7:16 am and sunset at 4:33 pm CST.
Sunshine
In Irwin, the average sunshine in December is 4.3h.UV index
January and December, with an average maximum UV index of 1, are months with the lowest UV index in Irwin. A UV Index estimate of 2, and below, represents a low threat to health from unprotected exposure to Sun's UV rays for ordinary individuals.Note: A daily high UV index of 1 in December leads to these guidelines:
People with sensitive skin, children, and babies should always be protected from prolonged sun exposure. UV radiation is strongest from the Sun during midday; protect yourself by staying in shaded areas. On sunny days, it's ideal to wear sunglasses that filter out UVA and UVB rays. Take to heart! Snow reflection can almost magnify the Sun's UV radiation twofold.
Frequently asked questions
How cold is it in Irwin in December?
What is the average humidity in December in Irwin?
How many days does it rain in December in Irwin?
How many days does it snow in December in Irwin?
What is the month with the shortest days in Irwin?
How many hours of daylight does Irwin have in December?
What time are sunrise and sunset in December in Irwin?
How long on average sun shines in December in Irwin?
What is the month with the lowest UV index in Irwin?
How high is the UV index in December in Irwin?
Average temperature in December
Irwin, IL
- Average high temperature in December: 36.3°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 (30°F).
- Average low temperature in December: 26.1°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 (18.3°F).
Average pressure in December
Irwin, IL
- Average pressure in December: 30.11"Hg
The month with the highest atmospheric pressure is January (30.12"Hg).
The month with the lowest atmospheric pressure is June (29.92"Hg).
Average wind speed in December
Irwin, IL
- Average wind speed in December: 9.6mph
The windiest months (with the highest average wind speed) are January and April (10.2mph).
The calmest month (with the lowest average wind speed) is August (6.2mph).
Average humidity in December
Irwin, IL
- Average humidity in December: 81%
The month with the highest relative humidity is July (85%).
The month with the lowest relative humidity is October (72%).
Average rainfall in December
Irwin, IL
- Average rainfall in December: 1.14"
The wettest month (with the highest rainfall) is May (3.27").
The driest month (with the least rainfall) is February (1.06").
Average rainfall days in December
Irwin, IL
- Average rainfall days in December: 7.3 days
The month with the highest number of rainy days is May (17.8 days).
The month with the least rainy days is February (5 days).
Average snowfall in December
Irwin, IL
- Average snowfall in December: 1.54"
The month with the highest snowfall is January (2.17").
The months with the least snowfall are May, June, July, August and September (0").
Average snowfall days in December
Irwin, IL
- Average snowfall days in December: 8.5 days
The month with the highest number of snowfall days is January (11.7 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
Irwin, IL
- Average daylight in December: 9h and 2min
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 18min).
- Average sunshine in December: 4h and 2min
The months with the most sunshine are June and July (Average sunshine: 9h and 42min).
The month with the least sunshine is January (Average sunshine: 3h and 48min).
Average sunshine days in December
Irwin, IL
- Average sunshine days in December: 16.8 days
The month with the most sunshine days is November (18.7 days).
The month with the least sunshine days is July (9.3 days).
Average UV index in December
Irwin, IL
- Average UV index in December: 1
The months with the highest UV index are June and July (UV index 6).
The months with the lowest UV index are January and December (UV index 1).
Average cloud cover in December
Irwin, IL
- Average cloud cover in December: 57
The month with the most cloud cover is January (Cloud cover 60).
The months with the least cloud cover are August and September (Cloud cover 34).
Average visibility in December
Irwin, 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).
Irwin, Illinois, USA
Weather forecast for your location
2. Allow the app to use your location
