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
December brings a decrease in the average high-temperature, falling from November's frosty 46.2°F (7.9°C) to a cold 35.2°F (1.8°C). A steady low-temperature average of 26.4°F (-3.1°C) is logged in Merrionette Park during December, reflecting a modest dip from daytime readings.Humidity
The average relative humidity in December is 80%.Rainfall
December is the month with the least rainfall. Rain falls for 7.4 days and accumulates 1.02" (26mm) of precipitation.Snowfall
January through April, October through December are months with snowfall. In Merrionette Park, in December, snow falls for 9.4 days, with typically accumulated 1.5" (38mm) of snow. In Merrionette Park, during the entire year, snow falls for 42.4 days and aggregates up to 11.61" (295mm) of snow.Daylight
December has the shortest days of the year in Merrionette Park, 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, in Merrionette Park, sunrise is at 7:17 am and sunset at 4:30 pm CST.
Sunshine
In Merrionette Park, the average sunshine in December is 4.2h.UV index
December is the month with the lowest UV index in Merrionette Park, with an average maximum UV index of 1. A UV Index reading of 2, and below, represents a low threat to health from exposure to the Sun's UV rays for the average person.Note: In December, the maximum UV index of 1 translates into these guidelines:
Although the majority can endure up to an hour in the sun without burns, children always require sun protection. Midday Sun has the strongest UV rays, making it crucial to limit exposure and find shade. To best shield against UV radiation, choose sun-safe garments and dependable sunglasses. Be advised! The UV radiation from the Sun can be almost doubled due to the reflective properties of snow.
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 much does it rain in December?
How much does it snow in December?
What is the month with the shortest days?
What is the average length of the day in December?
When 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 intensity in December?
Average temperature in December
Merrionette Park, IL
- Average high temperature in December: 35.2°F
The warmest month (with the highest average high temperature) is July (81°F).
The month with the lowest average high temperature is January (29.5°F).
- Average low temperature in December: 26.4°F
The month with the highest average low temperature is July (66.6°F).
The coldest month (with the lowest average low temperature) is January (18.9°F).
Average pressure in December
Merrionette Park, IL
- Average pressure in December: 30.09"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
Merrionette Park, IL
- Average wind speed in December: 9.9mph
The windiest month (with the highest average wind speed) is January (10.6mph).
The calmest month (with the lowest average wind speed) is August (6.5mph).
Average humidity in December
Merrionette Park, IL
- Average humidity in December: 80%
The months with the highest relative humidity are January and February (82%).
The month with the lowest relative humidity is October (72%).
Average rainfall in December
Merrionette Park, IL
- Average rainfall in December: 1.02"
The wettest month (with the highest rainfall) is May (3.07").
The driest month (with the least rainfall) is December (1.02").
Average rainfall days in December
Merrionette Park, IL
- Average rainfall days in December: 7.4 days
The month with the highest number of rainy days is July (18 days).
The month with the least rainy days is February (4.9 days).
Average snowfall in December
Merrionette Park, IL
- Average snowfall in December: 1.5"
The month with the highest snowfall is February (3.07").
The months with the least snowfall are May, June, July, August and September (0").
Average snowfall days in December
Merrionette Park, IL
- Average snowfall days in December: 9.4 days
The month with the highest number of snowfall days is January (11.8 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
Merrionette Park, IL
- Average daylight in December: 9h and 1min
The month with the longest days is June (Average daylight: 15h and 12min).
The month with the shortest days is December (Average daylight: 9h and 12min).
- Average sunshine in December: 4h and 1min
The month with the most sunshine is August (Average sunshine: 10h and 30min).
The month with the least sunshine is January (Average sunshine: 3h and 42min).
Average sunshine days in December
Merrionette Park, IL
- Average sunshine days in December: 15.5 days
The month with the most sunshine days is November (17.5 days).
The month with the least sunshine days is July (9.8 days).
Average UV index in December
Merrionette Park, IL
- Average UV index in December: 1
The months with the highest UV index are June, July and August (UV index 6).
The month with the lowest UV index is December (UV index 1).
Average cloud cover in December
Merrionette Park, IL
- Average cloud cover in December: 57
The month with the most cloud cover is January (Cloud cover 60).
The month with the least cloud cover is August (Cloud cover 28).
Average visibility in December
Merrionette Park, 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).
Merrionette Park, Illinois, USA
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