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 Janesville, the average high-temperature in December drops from a chilly 43.5°F (6.4°C) in November to a subzero cold 30.2°F (-1°C). Janesville experiences a consistent average temperature of 19.8°F (-6.8°C) throughout the nights in December.Humidity
In December, the average relative humidity is 83%.Rainfall
In Janesville, Iowa, in December, it is raining for 5.7 days, with typically 1.54" (39mm) of accumulated precipitation. In Janesville, during the entire year, the rain falls for 138.7 days and collects up to 28.78" (731mm) of precipitation.Snowfall
Months with snowfall are January through May, October through December. In Janesville, during December, snow falls for 9.5 days and regularly aggregates up to 3.39" (86mm) of snow. Throughout the year, there are 43.6 snowfall days, and 19.25" (489mm) of snow is accumulated.Daylight
The month with the shortest days in Janesville is December, with an average of 9h and 6min of daylight.On the first day of the month, sunrise is at 7:20 am and sunset at 4:37 pm. On the last day of December, sunrise is at 7:39 am and sunset at 4:46 pm CST.
Sunshine
The average sunshine in December is 4.3h.UV index
The months with the lowest UV index are January and December, with an average maximum UV index of 1. A UV Index reading of 2, and below, represents a minimal health vulnerability from exposure to the Sun's UV radiation for the ordinary person.Note: A typical high UV index of 1 in December suggests the following recommendations:
Despite most people tolerating extended sun exposure, it is critical to always protect those with sensitive skin, infants, and children. Solar radiation peaks around mid-day, so it's wise to limit exposure to the Sun at this time. In bright sunlight, prioritize sunglasses that grant protection from UVA and UVB radiation. On your guard! Snow's reflection 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 December?
What is the average humidity in December?
How much does it rain in Janesville 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?
When is the sunrise / sunset in December?
How many hours of sunshine does Janesville have in December?
What is the month with the lowest UV index?
What is the UV index intensity in December?
Average temperature in December
Janesville, IA
- Average high temperature in December: 30.2°F
The warmest month (with the highest average high temperature) is July (79.5°F).
The month with the lowest average high temperature is January (23.9°F).
- Average low temperature in December: 19.8°F
The month with the highest average low temperature is July (63°F).
The coldest month (with the lowest average low temperature) is January (11.3°F).
Average pressure in December
Janesville, IA
- 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 (29.89"Hg).
Average wind speed in December
Janesville, IA
- Average wind speed in December: 10mph
The windiest month (with the highest average wind speed) is April (10.7mph).
The calmest month (with the lowest average wind speed) is August (7mph).
Average humidity in December
Janesville, IA
- Average humidity in December: 83%
The month with the highest relative humidity is January (87%).
The month with the lowest relative humidity is October (72%).
Average rainfall in December
Janesville, IA
- Average rainfall in December: 1.54"
The wettest month (with the highest rainfall) is June (4.29").
The driest month (with the least rainfall) is January (1.02").
Average rainfall days in December
Janesville, IA
- Average rainfall days in December: 5.7 days
The month with the highest number of rainy days is June (19.4 days).
The month with the least rainy days is February (3.9 days).
Average snowfall in December
Janesville, IA
- Average snowfall in December: 3.39"
The month with the highest snowfall is February (5.08").
The months with the least snowfall are June, July, August and September (0").
Average snowfall days in December
Janesville, IA
- Average snowfall days in December: 9.5 days
The month with the highest number of snowfall days is January (10.5 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, IA
- 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: 4h and 2min
The month with the most sunshine is July (Average sunshine: 9h and 54min).
The month with the least sunshine is January (Average sunshine: 3h and 48min).
Average sunshine days in December
Janesville, IA
- Average sunshine days in December: 17.6 days
The months with the most sunshine days are October and November (17.8 days).
The month with the least sunshine days is June (9.2 days).
Average UV index in December
Janesville, IA
- 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, IA
- Average cloud cover in December: 57
The month with the most cloud cover is January (Cloud cover 61).
The month with the least cloud cover is August (Cloud cover 31).
Average visibility in December
Janesville, IA
- Average visibility in December: 6mi
The months with the highest visibility are February, March, April, May, June, September, October, November and December (6mi).
The months with the lowest visibility are January, July and August (5mi).
Janesville, Iowa, USA
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