December weather forecast
Rock Falls, WI

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Weather in December

December, the first month of the winter in Rock Falls, is also a subzero cold month, with an average temperature ranging between min 14.9°F (-9.5°C) and max 25.3°F (-3.7°C).

Temperature

December's arrival signals a distinct temperature shift, dropping from a wintry 40.1°F (4.5°C) in November to a subzero cold 25.3°F (-3.7°C). During December, the temperature is averaged to a low of 14.9°F (-9.5°C) at night.

Humidity

In December, the average relative humidity is 89%.

Rainfall

In Rock Falls, in December, it is raining for 5.2 days, with typically 1.38" (35mm) of accumulated precipitation. In Rock Falls, during the entire year, the rain falls for 135.6 days and collects up to 26.57" (675mm) of precipitation.

Snowfall

Months with snowfall are January through May, October through December. In December, it is snowing for 13.8 days. Throughout December, 5.2" (132mm) of snow is accumulated. In Rock Falls, during the entire year, snow falls for 69.2 days and aggregates up to 26.02" (661mm) of snow.

Daylight

December has the shortest days of the year, with an average of 8h and 54min of daylight.
On the first day of December, sunrise is at 7:24 am and sunset at 4:27 pm. On the last day of the month, sunrise is at 7:43 am and sunset at 4:36 pm CST.

Sunshine

The average sunshine in December is 3.1h.

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 low threat to health from exposure to the Sun's UV radiation for ordinary individuals.
Note: An average UV index of 1 in December transforms into this advice:
Most individuals face no significant issues with extended sun exposure, but it is always essential to protect children, babies, and those with sensitive skin. Considering the Sun's intensity during midday, it's wise to minimize direct exposure. A wide-brimmed hat is a staple for defending the face, eyes, ears, and neck from the Sun. Notice! The UV radiation of the Sun can be intensified nearly twofold due to the reflective quality of snow.
Updated: Jun 29, 2024
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate

Frequently asked questions

How cold is December in Rock Falls?

In Rock Falls, in December, the average high-temperature is 25.3°F (-3.7°C), and the average low-temperature is 14.9°F (-9.5°C).

What is the average humidity in December?

In Rock Falls, the average relative humidity in December is 89%.

How much does it rain in December?

In Rock Falls, during December, the rain falls for 5.2 days and regularly aggregates up to 1.38" (35mm) of precipitation.

How much does it snow in December?

In Rock Falls, in December, during 13.8 snowfall days, 5.2" (132mm) of snow is typically accumulated.

What is the month with the shortest days?

With an average of 8h and 54min of daylight, December has the shortest days of the year.

What is the average length of the day in December?

The average day length in December is 8h and 52min.

When is the sunrise / sunset in December?

On the first day of December, sunrise is at 7:24 am and sunset at 4:27 pm. On the last day of the month, sunrise is at 7:43 am and sunset at 4:36 pm CST.

How many hours of sunshine does Rock Falls have in December?

In December, the average sunshine duration is 3.1h.

What is the month with the lowest UV index?

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

What is the UV index reading in December?

In Rock Falls, the average daily maximum UV index in December is 1. A UV Index estimate of 2, and below, represents a minimal health vulnerability from unprotected exposure to 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
Rock Falls, WI

Average temperature in December - Rock Falls, WI
  • Average high temperature in December: 25.3°F

The warmest month (with the highest average high temperature) is July (78.4°F).
The month with the lowest average high temperature is January (19.9°F).

  • Average low temperature in December: 14.9°F

The month with the highest average low temperature is July (60.6°F).
The coldest month (with the lowest average low temperature) is January (6.3°F).

Average pressure in December
Rock Falls, WI

Average pressure in December - Rock Falls, WI
  • Average pressure in December: 30.1"Hg

The month with the highest atmospheric pressure is January (30.13"Hg).
The month with the lowest atmospheric pressure is June (29.89"Hg).

Average wind speed in December
Rock Falls, WI

Average wind speed in December - Rock Falls, WI
  • Average wind speed in December: 8.5mph

The windiest month (with the highest average wind speed) is April (9.3mph).
The calmest month (with the lowest average wind speed) is July (6.4mph).

Average humidity in December
Rock Falls, WI

Average humidity in December - Rock Falls, WI
  • Average humidity in December: 89%

The months with the highest relative humidity are January and February (91%).
The months with the lowest relative humidity are April and October (77%).

Average rainfall in December
Rock Falls, WI

Average rainfall in December - Rock Falls, WI
  • Average rainfall in December: 1.38"

The wettest month (with the highest rainfall) is June (4.57").
The driest month (with the least rainfall) is January (0.87").

Average rainfall days in December
Rock Falls, WI

Average rainfall days in December - Rock Falls, WI
  • Average rainfall days in December: 5.2 days

The month with the highest number of rainy days is June (17.9 days).
The month with the least rainy days is February (3.6 days).

Average snowfall in December
Rock Falls, WI

Average snowfall in December - Rock Falls, WI
  • Average snowfall in December: 5.2"

The month with the highest snowfall is February (6.38").
The months with the least snowfall are June, July, August and September (0").

Average snowfall days in December
Rock Falls, WI

Average snowfall days in December - Rock Falls, WI
  • Average snowfall days in December: 13.8 days

The month with the highest number of snowfall days is January (16.9 days).
The months with the least snowfall days are June, July, August and September (0 days).

Average daylight in December /
Average sunshine in December
Rock Falls, WI

Average daylight in December / Average sunshine in December - Rock Falls, WI
  • Average daylight in December: 8h and 5min

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 1min

The months with the most sunshine are July and August (Average sunshine: 9h and 36min).
The month with the least sunshine is January (Average sunshine: 3h and 0min).

Average sunshine days in December
Rock Falls, WI

Average sunshine days in December - Rock Falls, WI
  • Average sunshine days in December: 15.1 days

The month with the most sunshine days is October (16.3 days).
The month with the least sunshine days is June (9.8 days).

Average UV index in December
Rock Falls, WI

Average UV index in December - Rock Falls, WI
  • Average UV index in December: 1

The month with the highest UV index is July (UV index 6).
The months with the lowest UV index are January, February, November and December (UV index 1).

Average cloud cover in December
Rock Falls, WI

Average cloud cover in December - Rock Falls, WI
  • Average cloud cover in December: 67

The month with the most cloud cover is January (Cloud cover 68).
The month with the least cloud cover is August (Cloud cover 33).

Average visibility in December
Rock Falls, WI

Average visibility in December - Rock Falls, WI
  • Average visibility in December: 5mi

The months with the highest visibility are April, May, June, August, October and November (6mi).
The month with the lowest visibility is January (4mi).

Rock Falls, Wisconsin, USA

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