December weather forecastSullivan, WI
December
Weather in December
December, the first month of the winter in Sullivan, is also a subzero cold month, with an average temperature ranging between max 31.1°F (-0.5°C) and min 21.2°F (-6°C).Temperature
December shows a mild decline in the average high-temperature, falling from November's chilly 43.7°F (6.5°C) to a subzero cold 31.1°F (-0.5°C). In December, Sullivan encounters an average low-temperature of 21.2°F (-6°C) during the night.Humidity
In Sullivan, Wisconsin, the average relative humidity in December is 84%.Rainfall
The month with the least rainfall is December, when the rain falls for 6.5 days and typically collects 0.55" (14mm) of precipitation.Snowfall
Months with snowfall are January through May, October through December. In Sullivan, in December, during 9.5 snowfall days, 0.98" (25mm) of snow is typically accumulated. In Sullivan, Wisconsin, during the entire year, snow falls for 46.4 days and aggregates up to 7.48" (190mm) of snow.Daylight
With an average of 9h and 6min of daylight, December has the shortest days of the year in Sullivan.On the first day of December in Sullivan, sunrise is at 7:06 am and sunset at 4:20 pm. On the last day of the month, sunrise is at 7:25 am and sunset at 4:29 pm CST.
Sunshine
In Sullivan, Wisconsin, the average sunshine in December is 3.8h.UV index
January, November 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 exposure to the Sun's UV rays for the average person.Note: The UV index of 1 during December translates into the following guidance:
In contrast to children, who must always be shielded from the sun, most people can tolerate up to an hour of sun exposure without any burns. UV radiation from the Sun is most dangerous during midday; take precautions and seek shade. Sunglasses that guard against UVA and UVB rays are pivotal in minimizing sun-induced ocular damage. Consider carefully! The reflective quality of 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
Average temperature in December
Sullivan, WI
- Average high temperature in December: 31.1°F
The warmest month (with the highest average high temperature) is July (79.3°F).
The month with the lowest average high temperature is January (24.3°F).
- Average low temperature in December: 21.2°F
The month with the highest average low temperature is July (61.5°F).
The coldest month (with the lowest average low temperature) is January (12.2°F).
Average pressure in December
Sullivan, WI
- Average pressure in December: 30.09"Hg
The months with the highest atmospheric pressure are January and February (30.1"Hg).
The month with the lowest atmospheric pressure is June (29.91"Hg).
Average wind speed in December
Sullivan, WI
- Average wind speed in December: 9.1mph
The windiest month (with the highest average wind speed) is April (9.9mph).
The calmest month (with the lowest average wind speed) is August (6.3mph).
Average humidity in December
Sullivan, WI
- Average humidity in December: 84%
The month with the highest relative humidity is January (88%).
The month with the lowest relative humidity is April (76%).
Average rainfall in December
Sullivan, WI
- Average rainfall in December: 0.55"
The wettest month (with the highest rainfall) is July (1.93").
The driest month (with the least rainfall) is December (0.55").
Average rainfall days in December
Sullivan, WI
- Average rainfall days in December: 6.5 days
The months with the highest number of rainy days are May and July (15.7 days).
The month with the least rainy days is January (2.8 days).
Average snowfall in December
Sullivan, WI
- Average snowfall in December: 0.98"
The month with the highest snowfall is January (2.13").
The months with the least snowfall are June, July, August and September (0").
Average snowfall days in December
Sullivan, WI
- Average snowfall days in December: 9.5 days
The month with the highest number of snowfall days is January (12.8 days).
The months with the least snowfall days are June, July, August and September (0 days).
Average daylight in December /
Average sunshine in December
Sullivan, WI
- Average daylight in December: 9h and 6min
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 48min
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 24min).
Average sunshine days in December
Sullivan, WI
- Average sunshine days in December: 17.7 days
The month with the most sunshine days is November (18.7 days).
The month with the least sunshine days is July (11.6 days).
Average UV index in December
Sullivan, WI
- Average UV index in December: 1
The months with the highest UV index are May, June, July and August (UV index 5).
The months with the lowest UV index are January, November and December (UV index 1).
Average cloud cover in December
Sullivan, WI
- Average cloud cover in December: 61
The month with the most cloud cover is January (Cloud cover 65).
The month with the least cloud cover is August (Cloud cover 34).
Average visibility in December
Sullivan, 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).
