December weather forecast
Galena, IL

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Bright brown and golden trees near a calm river, bridge, and the colorful town of Galena, Illinois,
Bright brown and golden trees near a calm river, bridge, and the colorful town of Galena, Illinois,

Weather in December

December in Galena ushers in the full swing of winter, with dropping temperatures and increasing snowfall. The weather can be characterized by its lower visibility, limited to an average of 6 miles. Despite the inclement conditions, the Christmas festivities provide a burst of warmth. Moreover, the pressure begins to increase, albeit minimally, hinting at the end of the cycle. The weather spiral completes with this month, preparing to start anew with the coming January.

Temperature

Galena's December weather comes with a decrease in average high-temperatures, moving from a frosty 44.2°F (6.8°C) in November to a subzero cold 31.8°F (-0.1°C). December brings Galena a consistent average low-temperature of 21.4°F (-5.9°C).

Humidity

The average relative humidity in December is 83%.

Rainfall

In Galena, during December, the rain falls for 7.6 days and regularly aggregates up to 1.5" (38mm) of precipitation. In Galena, during the entire year, the rain falls for 153.1 days and collects up to 30.75" (781mm) of precipitation.

Snowfall

Months with snowfall are January through April, October through December. In December, it is snowing for 10.5 days. Throughout December, 3.03" (77mm) of snow is accumulated. In Galena, Illinois, during the entire year, snow falls for 46.9 days and aggregates up to 17.52" (445mm) of snow.

Daylight

With an average of 9h and 6min of daylight, December has the shortest days of the year.
On the first day of the month, sunrise is at 7:12 am and sunset at 4:29 pm. On the last day of December, sunrise is at 7:30 am and sunset at 4:39 pm CST.

Sunshine

The average sunshine in December is 4.1h.

UV index

January and December, with an average maximum UV index of 1, are months with the lowest UV index. A UV Index of 2, and less, symbolizes a minimal health vulnerability from unsafe exposure to UV radiation for ordinary individuals.
Note: The UV index of 1 during December leads to these advisories:
Children necessitate constant protection from sunlight, unlike the majority, who can remain under the sun for about an hour without burning. UV radiation is strongest from the Sun during midday; protect yourself by staying in shaded areas. Sunglasses that ward off UVA and UVB rays play a pivotal role in reducing solar eye damage. Be careful! The Sun's UV radiation can nearly be doubled by the reflective quality of snow.
Updated: Aug 19, 2024
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate

Frequently asked questions

How cold is December?

In Galena, 31.8°F (-0.1°C) is the average high-temperature and 21.4°F (-5.9°C) is the average low-temperature during December.

What is the average humidity in December?

In December, the average relative humidity is 83%.

How many days does it rain in December?

In Galena, in December, during 7.6 rainfall days, 1.5" (38mm) of precipitation is typically accumulated.

How many days does it snow in December?

In Galena, in December, during 10.5 snowfall days, 3.03" (77mm) of snow is typically accumulated.

What is the month with the shortest days?

December has the shortest days of the year, with an average of 9h and 6min of daylight.

What is the average length of the day in December?

The average day length in December is 9h and 8min.

What time are sunrise and sunset in December?

In December, on the first day of the month, sunrise is at 7:12 am and sunset at 4:29 pm. On the last day of the month, sunrise is at 7:30 am and sunset at 4:39 pm CST.

How long on average sun shines in December in Galena?

In December, the average sunshine duration is 4.1h.

What are the months with the lowest UV index?

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

What is the UV index intensity in December?

In December, the average daily maximum UV index is 1. A UV Index of 2, and less, symbolizes a low health risk from unsafe exposure to Sun's UV rays.
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
Galena, IL

Average temperature in December - Galena, IL
  • Average high temperature in December: 31.8°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: 21.4°F

The month with the highest average low temperature is July (63°F).
The coldest month (with the lowest average low temperature) is January (12.4°F).

Average pressure in December
Galena, IL

Average pressure in December - Galena, IL
  • Average pressure in December: 30.1"Hg

The month with the highest atmospheric pressure is January (30.12"Hg).
The month with the lowest atmospheric pressure is June (29.9"Hg).

Average wind speed in December
Galena, IL

Average wind speed in December - Galena, IL
  • Average wind speed in December: 9.6mph

The windiest month (with the highest average wind speed) is April (10.4mph).
The calmest month (with the lowest average wind speed) is August (6.6mph).

Average humidity in December
Galena, IL

Average humidity in December - Galena, IL
  • 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
Galena, IL

Average rainfall in December - Galena, IL
  • Average rainfall in December: 1.5"

The wettest month (with the highest rainfall) is June (4.29").
The driest month (with the least rainfall) is January (1.26").

Average rainfall days in December
Galena, IL

Average rainfall days in December - Galena, IL
  • Average rainfall days in December: 7.6 days

The month with the highest number of rainy days is May (20 days).
The month with the least rainy days is February (4.8 days).

Average snowfall in December
Galena, IL

Average snowfall in December - Galena, IL
  • Average snowfall in December: 3.03"

The month with the highest snowfall is January (5.12").
The months with the least snowfall are May, June, July, August and September (0").

Average snowfall days in December
Galena, IL

Average snowfall days in December - Galena, IL
  • Average snowfall days in December: 10.5 days

The month with the highest number of snowfall days is January (13.2 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
Galena, IL

Average daylight in December / Average sunshine in December - Galena, IL
  • Average daylight in December: 9h and 1min

The month with the longest days is June (Average daylight: 15h and 12min).
The month with the shortest days is December (Average daylight: 9h and 6min).

  • Average sunshine in December: 4h and 1min

The month with the most sunshine is August (Average sunshine: 9h and 48min).
The month with the least sunshine is January (Average sunshine: 3h and 42min).

Average sunshine days in December
Galena, IL

Average sunshine days in December - Galena, IL
  • Average sunshine days in December: 15.7 days

The month with the most sunshine days is November (17.1 days).
The month with the least sunshine days is June (7.9 days).

Average UV index in December
Galena, IL

Average UV index in December - Galena, IL
  • Average UV index in December: 1

The months with the highest UV index are June and July (UV index 6).
The months with the lowest UV index are January and December (UV index 1).

Average cloud cover in December
Galena, IL

Average cloud cover in December - Galena, IL
  • Average cloud cover in December: 58

The month with the most cloud cover is January (Cloud cover 62).
The month with the least cloud cover is September (Cloud cover 32).

Average visibility in December
Galena, IL

Average visibility in December - Galena, IL
  • Average visibility in December: 6mi

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

Galena, Illinois, USA

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