December weather forecastGreen Bay, WI
December
Weather in December
December is dominated by cold temperatures and snowfall, prepping Green Bay for the deep winter ahead. With an average snowfall of 4.76" (121mm), December ranks second in snowfall accumulation, next only to January. The daylight hours drop to a mere 8.9 hours, the shortest in the year, with sun shining for only around 3.6 hours a day on average. The sea temperature also significantly drops to 41.5°F (5.3°C), adding to the overall chill. It is worth noting that as the month progresses, the days start to gradually lengthen, offering a glimmer of the approaching spring even amid the harsh winter.Temperature
Green Bay, Wisconsin, experiences a temperature shift at the start of December, with average high-temperatures adjusting from an icy 41.7°F (5.4°C) in November to a subzero cold 28.8°F (-1.8°C). In Green Bay, the nocturnal temperatures throughout December show a marginal dip from the daytime averages, settling at a still freezing cold 19.9°F (-6.7°C).Humidity
The average relative humidity in December is 85%.Rainfall
In Green Bay, in December, it is raining for 6.5 days, with typically 1.73" (44mm) of accumulated precipitation. Throughout the year, there are 130.8 rainfall days, and 24.8" (630mm) of precipitation is accumulated.Snowfall
January through May, October through December are months with snowfall. In Green Bay, in December, during 13.6 snowfall days, 4.76" (121mm) of snow is typically accumulated. In Green Bay, during the entire year, snow falls for 63.7 days and aggregates up to 23.27" (591mm) of snow.Ocean temperature
In Green Bay, the average seawater temperature in December is 41.5°F (5.3°C).Note: Engaging in a swim in 41.5°F (5.3°C) can threaten life. Brief exposure to 55.4°F (13°C) waters is uneasy, and submersion below 50°F (10°C) can lead to cold shock and disrupted breathing patterns, varying by individual.
Daylight
With an average of 8h and 54min of daylight, December has the shortest days of the year.On the first day of the month, sunrise is at 7:09 am and sunset at 4:13 pm. On the last day of December, sunrise is at 7:28 am and sunset at 4:22 pm CST.
Sunshine
The average sunshine in December is 3.6h.UV index
January, February, 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 vulnerability from unprotected exposure to Sun's UV rays for average individuals.Note: The maximum UV index, 1 during December, leads to the following recommendations:
Extended sun exposure is not an issue for the majority. Children, infants, and fair-skinned individuals always need to be protected. The Sun's UV radiation is especially harmful around midday, so reduce exposure and stay safe. Sunglasses that guard against UVA and UVB rays are pivotal in minimizing sun-induced ocular damage. Warning! The reflection from snow can nearly magnify the Sun's UV radiation twofold.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in December
Green Bay, WI
- Average high temperature in December: 28.8°F
The warmest month (with the highest average high temperature) is July (78.1°F).
The month with the lowest average high temperature is January (22.6°F).
- Average low temperature in December: 19.9°F
The month with the highest average low temperature is July (60.4°F).
The coldest month (with the lowest average low temperature) is January (12.4°F).
Average pressure in December
Green Bay, WI
- Average pressure in December: 30.07"Hg
The month with the highest atmospheric pressure is March (30.09"Hg).
The month with the lowest atmospheric pressure is June (29.91"Hg).
Average wind speed in December
Green Bay, WI
- Average wind speed in December: 9.9mph
The windiest months (with the highest average wind speed) are January and February (10.1mph).
The calmest months (with the lowest average wind speed) are July and August (7.2mph).
Average humidity in December
Green Bay, WI
- Average humidity in December: 85%
The month with the highest relative humidity is January (88%).
The months with the lowest relative humidity are April and May (76%).
Average rainfall in December
Green Bay, WI
- Average rainfall in December: 1.73"
The wettest month (with the highest rainfall) is May (3.31").
The driest month (with the least rainfall) is January (1.18").
Average rainfall days in December
Green Bay, WI
- Average rainfall days in December: 6.5 days
The month with the highest number of rainy days is May (15.9 days).
The month with the least rainy days is February (3.7 days).
Average snowfall in December
Green Bay, WI
- Average snowfall in December: 4.76"
The month with the highest snowfall is February (5.79").
The months with the least snowfall are June, July, August and September (0").
Average snowfall days in December
Green Bay, WI
- Average snowfall days in December: 13.6 days
The month with the highest number of snowfall days is January (15.9 days).
The months with the least snowfall days are June, July, August and September (0 days).
Average sea temperature in December
Green Bay, WI
- Average sea temperature in December: 41.5°F
The best month for swimming (with the highest average sea temperature) is August (67.6°F).
The coldest month (with the lowest average sea temperature) is February (36.1°F).
Average daylight in December /
Average sunshine in December
Green Bay, WI
- Average daylight in December: 8h and 54min
The month with the longest days is June (Average daylight: 15h and 30min).
The month with the shortest days is December (Average daylight: 8h and 54min).
- Average sunshine in December: 3h and 36min
The month with the most sunshine is July (Average sunshine: 10h and 6min).
The month with the least sunshine is February (Average sunshine: 3h and 24min).
Average sunshine days in December
Green Bay, WI
- Average sunshine days in December: 13.9 days
The months with the most sunshine days are September and November (17 days).
The month with the least sunshine days is April (11.6 days).
Average UV index in December
Green Bay, WI
- Average UV index in December: 1
The months with the highest UV index are June, July and August (UV index 5).
The months with the lowest UV index are January, February, November and December (UV index 1).
Average cloud cover in December
Green Bay, WI
- Average cloud cover in December: 63
The month with the most cloud cover is January (Cloud cover 65).
The months with the least cloud cover are July and August (Cloud cover 33).
Average visibility in December
Green Bay, WI
- Average visibility in December: 6mi
The months with the highest visibility are March, April, May, June, July, August, September, October, November and December (6mi).
The months with the lowest visibility are January and February (5mi).
