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
Observing a mild shift, the average high-temperature during December reduces from November's chilly 47.5°F (8.6°C) to a wintry 35.4°F (1.9°C). Henderson encounters a steady low-temperature average of 24.6°F (-4.1°C) throughout the month of December.Humidity
In December, the average relative humidity is 81%.Rainfall
January and December are months with the least rain when the rain falls for 4.5 days and typically aggregates up to 0.47" (12mm) of rain.Snowfall
January through April, October through December are months with snowfall. In December, it is snowing for 6 days. Throughout December, 0.43" (11mm) of snow is accumulated. Throughout the year, there are 28 snowfall days, and 4.53" (115mm) of snow is accumulated.Daylight
December has the shortest days of the year, with an average of 9h and 18min of daylight.On the first day of the month, sunrise is at 7:07 am and sunset at 4:33 pm. On the last day of December, sunrise is at 7:26 am and sunset at 4:43 pm CST.
Sunshine
In Henderson, the average sunshine in December is 4.4h.UV index
The month with the lowest UV index in Henderson is December, with an average maximum UV index of 1. A UV Index of 2, and less, symbolizes a low threat to health from unprotected exposure to Sun's UV rays for the ordinary person.Note: In December, a regular UV index of 1 translates into these guidelines:
Extended sun exposure is not an issue for the majority. Children, infants, and fair-skinned individuals always need to be protected. The Sun's UV radiation is especially harmful around midday, so reduce exposure and stay safe. It's wise to wear UVA and UVB-blocking sunglasses when the sun shines brightly. Take careful note! The UV radiation of the Sun can be nearly doubled by snow reflection.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
How cold is it in December?
What is the average humidity in December?
What is the driest month?
How many days does it rain in December?
How many days does it snow in December?
What is the month with the shortest days?
What is the average length of the day in December?
What time are sunrise and sunset in December?
How long on average sun shines in December?
What is the month with the lowest UV index?
What is the UV index reading in December?
Average temperature in December
Henderson, IL
- Average high temperature in December: 35.4°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 (29.5°F).
- Average low temperature in December: 24.6°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 (17.4°F).
Average pressure in December
Henderson, 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 (29.91"Hg).
Average wind speed in December
Henderson, IL
- Average wind speed in December: 9.9mph
The windiest month (with the highest average wind speed) is April (10.8mph).
The calmest months (with the lowest average wind speed) are July and August (6.8mph).
Average humidity in December
Henderson, IL
- Average humidity in December: 81%
The month with the highest relative humidity is July (84%).
The month with the lowest relative humidity is October (72%).
Average rainfall in December
Henderson, IL
- Average rainfall in December: 0.47"
The wettest month (with the highest rainfall) is May (1.65").
The driest months (with the least rainfall) are January and December (0.47").
Average rainfall days in December
Henderson, IL
- Average rainfall days in December: 4.5 days
The month with the highest number of rainy days is May (15.2 days).
The month with the least rainy days is February (3.9 days).
Average snowfall in December
Henderson, IL
- Average snowfall in December: 0.43"
The month with the highest snowfall is January (1.38").
The months with the least snowfall are May, June, July, August and September (0").
Average snowfall days in December
Henderson, IL
- Average snowfall days in December: 6 days
The month with the highest number of snowfall days is January (8.8 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
Henderson, 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 month with the most sunshine is June (Average sunshine: 10h and 6min).
The month with the least sunshine is January (Average sunshine: 4h and 0min).
Average sunshine days in December
Henderson, IL
- Average sunshine days in December: 21.6 days
The month with the most sunshine days is December (21.6 days).
The month with the least sunshine days is June (12.4 days).
Average UV index in December
Henderson, 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
Henderson, IL
- Average cloud cover in December: 54
The month with the most cloud cover is January (Cloud cover 58).
The month with the least cloud cover is September (Cloud cover 30).
Average visibility in December
Henderson, IL
- Average visibility in December: 6mi
The months with the highest visibility are January, February, March, April, May, June, August, September, October, November and December (6mi).
The month with the lowest visibility is July (5mi).
Henderson, Illinois, USA
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