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
In December, the average high-temperature goes from a frosty 43.9°F (6.6°C) in November to a freezing cold 31.6°F (-0.2°C). The month of December records an average low-temperature of 21.7°F (-5.7°C).Humidity
In Janesville, the average relative humidity in December is 83%.Rainfall
In December, the rain falls for 6.5 days. Throughout December, 0.79" (20mm) of precipitation is accumulated. In Janesville, Wisconsin, during the entire year, the rain falls for 127.7 days and collects up to 17.87" (454mm) of precipitation.Snowfall
Months with snowfall are January through April, October through December. In Janesville, in December, snow falls for 9.1 days, with typically accumulated 1.61" (41mm) of snow. Throughout the year, there are 44.5 snowfall days, and 11.34" (288mm) of snow is accumulated.Daylight
December has the shortest days of the year, with an average of 9h and 6min of daylight.On the first day of the month, sunrise is at 7:07 am and sunset at 4:23 pm. On the last day of December, sunrise is at 7:26 am and sunset at 4:32 pm CST.
Sunshine
The average sunshine in December in Janesville is 3.9h.UV index
The months with the lowest UV index are January and December, with an average maximum UV index of 1. A UV Index value of 2, and less, symbolizes a minimal health vulnerability 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:
Extended sun exposure is not an issue for the majority. Children, infants, and fair-skinned individuals always need to be protected. Direct exposure to the Sun's intense radiation around midday should be avoided for health reasons. Boost your sun resistance with garments that are densely woven yet spacious. Consider this! The reflection from snow can almost double the intensity of the Sun's UV radiation.
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?
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 is the sunrise / sunset in December?
How long on average sun shines in December?
When is the lowest UV index in Janesville?
What is the UV index reading in December?
Average temperature in December
Janesville, WI
- Average high temperature in December: 31.6°F
The warmest month (with the highest average high temperature) is July (79.7°F).
The month with the lowest average high temperature is January (25°F).
- Average low temperature in December: 21.7°F
The month with the highest average low temperature is July (62.4°F).
The coldest month (with the lowest average low temperature) is January (12.9°F).
Average pressure in December
Janesville, WI
- 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 (29.91"Hg).
Average wind speed in December
Janesville, WI
- Average wind speed in December: 9.2mph
The windiest month (with the highest average wind speed) is April (10.1mph).
The calmest month (with the lowest average wind speed) is August (6.4mph).
Average humidity in December
Janesville, WI
- Average humidity in December: 83%
The month with the highest relative humidity is January (87%).
The months with the lowest relative humidity are April and October (76%).
Average rainfall in December
Janesville, WI
- Average rainfall in December: 0.79"
The wettest month (with the highest rainfall) is June (2.76").
The driest months (with the least rainfall) are January and February (0.75").
Average rainfall days in December
Janesville, WI
- Average rainfall days in December: 6.5 days
The month with the highest number of rainy days is June (16.3 days).
The month with the least rainy days is January (3.5 days).
Average snowfall in December
Janesville, WI
- Average snowfall in December: 1.61"
The month with the highest snowfall is January (2.83").
The months with the least snowfall are May, June, July, August and September (0").
Average snowfall days in December
Janesville, WI
- Average snowfall days in December: 9.1 days
The month with the highest number of snowfall days is January (12.5 days).
The months with the least snowfall days are June, July, August and September (0 days).
Average daylight in December /
Average sunshine in December
Janesville, WI
- Average daylight in December: 9h and 1min
The month with the longest days is June (Average daylight: 15h and 18min).
The month with the shortest days is December (Average daylight: 9h and 6min).
- Average sunshine in December: 3h and 5min
The months with the most sunshine are July and August (Average sunshine: 9h and 42min).
The month with the least sunshine is January (Average sunshine: 3h and 30min).
Average sunshine days in December
Janesville, WI
- Average sunshine days in December: 17.4 days
The month with the most sunshine days is November (19.1 days).
The month with the least sunshine days is June (10.9 days).
Average UV index in December
Janesville, WI
- Average UV index in December: 1
The month with the highest UV index is June (UV index 6).
The months with the lowest UV index are January and December (UV index 1).
Average cloud cover in December
Janesville, WI
- Average cloud cover in December: 60
The month with the most cloud cover is January (Cloud cover 64).
The month with the least cloud cover is September (Cloud cover 34).
Average visibility in December
Janesville, WI
- Average visibility in December: 6mi
The months with the highest visibility are March, April, May, June, October, November and December (6mi).
The months with the lowest visibility are January, February, July, August and September (5mi).
Janesville, Wisconsin, USA
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