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 suggests a modest reduction in the average high-temperature, shifting from a frosty 46°F (7.8°C) in November to a wintry 34.5°F (1.4°C). The average low-temperature of 24.1°F (-4.4°C) is witnessed in Boulder Hill during December.Humidity
In Boulder Hill, the average relative humidity in December is 82%.Rainfall
November and December are months with the least rain in Boulder Hill when the rain falls for 6.5 days and typically aggregates up to 0.75" (19mm) of rain.Snowfall
Months with snowfall in Boulder Hill are January through April, October through December. In Boulder Hill, during December, snow falls for 8.8 days and regularly aggregates up to 1.02" (26mm) of snow. In Boulder Hill, during the entire year, snow falls for 39.5 days and aggregates up to 6.69" (170mm) of snow.Daylight
With an average of 9h and 12min of daylight, December has the shortest days of the year in Boulder Hill, Illinois.On the first day of December, sunrise is at 7:01 am and sunset at 4:23 pm. On the last day of the month, sunrise is at 7:20 am and sunset at 4:33 pm CST.
Sunshine
In December, the average sunshine is 4.2h.UV index
January and December, with an average maximum UV index of 1, are months with the lowest UV index. A UV Index reading of 2, and below, represents a minimal health hazard from unsafe exposure to UV radiation for ordinary individuals.Note: In December, an average UV index of 1 transforms into the following instructions:
Those with sensitive skin, infants, and children require constant safeguarding from prolonged sun exposure. The midday Sun can be dangerous due to its intense radiation; always find shade and reduce exposure. In bright sunlight, prioritize sunglasses that grant protection from UVA and UVB radiation. Mark this! Snow reflection can nearly double the UV radiation intensity from the Sun.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
How cold is it in Boulder Hill in December?
What is the average humidity in December in Boulder Hill?
What is the driest month in Boulder Hill?
How many days does it rain in December in Boulder Hill?
How much does it snow in Boulder Hill in December?
What is the month with the shortest days in Boulder Hill?
How many hours of daylight does Boulder Hill have in December?
What time are sunrise and sunset in December in Boulder Hill?
How long on average sun shines in December in Boulder Hill?
When is the lowest UV index in Boulder Hill?
What is the UV index reading in December in Boulder Hill?
Average temperature in December
Boulder Hill, IL
- Average high temperature in December: 34.5°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 (28.4°F).
- Average low temperature in December: 24.1°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 (16.7°F).
Average pressure in December
Boulder Hill, 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
Boulder Hill, IL
- Average wind speed in December: 9mph
The windiest month (with the highest average wind speed) is April (9.7mph).
The calmest month (with the lowest average wind speed) is August (6mph).
Average humidity in December
Boulder Hill, IL
- Average humidity in December: 82%
The months with the highest relative humidity are January, February, July and August (83%).
The month with the lowest relative humidity is October (74%).
Average rainfall in December
Boulder Hill, IL
- Average rainfall in December: 0.75"
The wettest month (with the highest rainfall) is June (2.24").
The driest months (with the least rainfall) are November and December (0.75").
Average rainfall days in December
Boulder Hill, IL
- Average rainfall days in December: 6.5 days
The month with the highest number of rainy days is July (16.6 days).
The month with the least rainy days is February (4.3 days).
Average snowfall in December
Boulder Hill, IL
- Average snowfall in December: 1.02"
The month with the highest snowfall is January (1.73").
The months with the least snowfall are May, June, July, August and September (0").
Average snowfall days in December
Boulder Hill, IL
- Average snowfall days in December: 8.8 days
The month with the highest number of snowfall days is January (10.7 days).
The months with the least snowfall days are June, July, August and September (0 days).
Average daylight in December /
Average sunshine in December
Boulder Hill, 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 July (Average sunshine: 9h and 48min).
The month with the least sunshine is January (Average sunshine: 3h and 48min).
Average sunshine days in December
Boulder Hill, IL
- Average sunshine days in December: 17.7 days
The month with the most sunshine days is November (19.5 days).
The month with the least sunshine days is July (10.2 days).
Average UV index in December
Boulder Hill, 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
Boulder Hill, 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 September (Cloud cover 32).
Average visibility in December
Boulder Hill, 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).
Boulder Hill, Illinois, USA
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