December weather forecast
Byron, WI

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Weather in December

The first month of the winter, December, is still a freezing cold month in Byron, Wisconsin, with temperature in the range of an average low of 19.4°F (-7°C) and an average high of 29.1°F (-1.6°C).

Temperature

The shift from November to December involves a decrease in the average high-temperature, dropping from a cold 42.1°F (5.6°C) to a freezing cold 29.1°F (-1.6°C). An average temperature of 19.4°F (-7°C) marks the nights in December.

Humidity

In Byron, the average relative humidity in December is 86%.

Rainfall

In Byron, during December, the rain falls for 3.7 days and regularly aggregates up to 0.35" (9mm) of precipitation. Throughout the year, there are 90.7 rainfall days, and 7.56" (192mm) of precipitation is accumulated.

Snowfall

January through April, October through December are months with snowfall. In Byron, in December, snow falls for 9.3 days, with typically accumulated 0.67" (17mm) of snow. Throughout the year, there are 42 snowfall days, and 4.25" (108mm) of snow is accumulated.

Daylight

With an average of 9h and 0min of daylight, December has the shortest days of the year.
On the first day of December, sunrise is at 7:08 am and sunset at 4:18 pm. On the last day of the month, sunrise is at 7:27 am and sunset at 4:27 pm CST.

Sunshine

In Byron, the average sunshine in December is 3.6h.

UV index

January, November and December, with an average maximum UV index of 1, are months with the lowest UV index. A UV Index value of 2, and less, symbolizes a low threat to health from unprotected exposure to Sun's UV rays for the ordinary person.
Note: The maximum UV index, 1 during December, leads to the following recommendations:
Prolonged sun exposure generally does not trouble most people. However, it is vital to ensure protection for babies, children, and individuals with sensitive skin. Being in direct Sun during midday can be harmful due to intense solar radiation; take precautions. For optimum UV protection, wear sun-resistant attire complemented with a hat and quality shades. Note well! The intensity of the Sun's UV rays can be nearly doubled by snow reflection.
Updated: Aug 24, 2024
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate

Frequently asked questions

How cold is December?

December temperatures vary between a high-temperature of 29.1°F (-1.6°C) and a low-temperature of 19.4°F (-7°C).

What is the average humidity in December?

In Byron, the average relative humidity in December is 86%.

How many days does it rain in December?

In Byron, in December, during 3.7 rainfall days, 0.35" (9mm) of precipitation is typically accumulated.

How much does it snow in December?

In December, it is snowing for 9.3 days. Throughout December, 0.67" (17mm) of snow is accumulated.

What is the month with the shortest days?

With an average of 9h and 0min of daylight, December has the shortest days of the year.

How many hours of daylight does Byron have in December?

In Byron, the average day length in December is 9h and 0min.

When is the sunrise / sunset in December?

In December, on the first day of the month, sunrise is at 7:08 am and sunset at 4:18 pm. On the last day of the month, sunrise is at 7:27 am and sunset at 4:27 pm CST.

How many hours of sunshine does Byron have in December?

The average sunshine duration in December is 3.6h.

When is the lowest UV index?

The months with the lowest UV index are January, November and December, with an average maximum UV index of 1.

What is the UV index intensity in December?

The average daily maximum UV index in December is 1. A UV Index estimate of 2, and below, represents a low health risk from exposure to the Sun's UV radiation.
Average humidity
Average rainfall days
Average snowfall days
Average daylight
Average sunshine
Average sunshine days
Average UV index
Average cloud cover
Average visibility

Average temperature in December
Byron, WI

Average temperature in December - Byron, WI
  • Average high temperature in December: 29.1°F

The warmest month (with the highest average high temperature) is July (77.4°F).
The month with the lowest average high temperature is January (22.5°F).

  • Average low temperature in December: 19.4°F

The month with the highest average low temperature is July (61°F).
The coldest month (with the lowest average low temperature) is January (10.8°F).

Average pressure in December
Byron, WI

Average pressure in December - Byron, WI
  • Average pressure in December: 30.08"Hg

The months with the highest atmospheric pressure are January, February and March (30.09"Hg).
The month with the lowest atmospheric pressure is June (29.91"Hg).

Average wind speed in December
Byron, WI

Average wind speed in December - Byron, WI
  • Average wind speed in December: 9.9mph

The windiest month (with the highest average wind speed) is April (10.4mph).
The calmest month (with the lowest average wind speed) is August (7.1mph).

Average humidity in December
Byron, WI

Average humidity in December - Byron, WI
  • Average humidity in December: 86%

The month with the highest relative humidity is January (89%).
The month with the lowest relative humidity is April (76%).

Average rainfall in December
Byron, WI

Average rainfall in December - Byron, WI
  • Average rainfall in December: 0.35"

The wettest months (with the highest rainfall) are June and October (0.94").
The driest months (with the least rainfall) are January and February (0.31").

Average rainfall days in December
Byron, WI

Average rainfall days in December - Byron, WI
  • Average rainfall days in December: 3.7 days

The months with the highest number of rainy days are April and July (11 days).
The month with the least rainy days is February (2.3 days).

Average snowfall in December
Byron, WI

Average snowfall in December - Byron, WI
  • Average snowfall in December: 0.67"

The month with the highest snowfall is January (1.06").
The months with the least snowfall are May, June, July, August and September (0").

Average snowfall days in December
Byron, WI

Average snowfall days in December - Byron, WI
  • Average snowfall days in December: 9.3 days

The month with the highest number of snowfall days is January (10.5 days).
The months with the least snowfall days are May, June, July, August and September (0 days).

Average daylight in December /
Average sunshine in December
Byron, WI

Average daylight in December / Average sunshine in December - Byron, WI
  • Average daylight in December: 9h and 0min

The month with the longest days is June (Average daylight: 15h and 24min).
The month with the shortest days is December (Average daylight: 9h and 0min).

  • Average sunshine in December: 3h and 4min

The month with the most sunshine is July (Average sunshine: 10h and 0min).
The month with the least sunshine is January (Average sunshine: 3h and 24min).

Average sunshine days in December
Byron, WI

Average sunshine days in December - Byron, WI
  • Average sunshine days in December: 21.5 days

The month with the most sunshine days is December (21.5 days).
The month with the least sunshine days is June (15.6 days).

Average UV index in December
Byron, WI

Average UV index in December - Byron, 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
Byron, WI

Average cloud cover in December - Byron, WI
  • Average cloud cover in December: 63

The month with the most cloud cover is January (Cloud cover 65).
The month with the least cloud cover is July (Cloud cover 33).

Average visibility in December
Byron, WI

Average visibility in December - Byron, WI
  • Average visibility in December: 6mi

The months with the highest visibility are February, March, April, May, June, July, August, October, November and December (6mi).
The months with the lowest visibility are January and September (5mi).

Byron, Wisconsin, USA

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