December weather forecast
Rockton, IL

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Weather in December

December, the first month of the winter in Rockton, is also a wintry month, with temperature in the range of an average high of 32.4°F (0.2°C) and an average low of 21.7°F (-5.7°C).

Temperature

As December begins, there is a decrease in the average high-temperature, falling from a frosty 43.7°F (6.5°C) in November to an icy 32.4°F (0.2°C). Rockton observes an average nighttime temperature of 21.7°F (-5.7°C) during December.

Humidity

In Rockton, Illinois, the average relative humidity in December is 83%.

Rainfall

February and December are months with the least rain in Rockton, Illinois, when the rain falls for 5.5 days and typically aggregates up to 0.67" (17mm) of rain.

Snowfall

January through April, October through December are months with snowfall in Rockton. In December, it is snowing for 8.5 days. Throughout December, 1.1" (28mm) of snow is accumulated. In Rockton, during the entire year, snow falls for 41.2 days and aggregates up to 8.78" (223mm) of snow.

Daylight

December has the shortest days of the year in Rockton, with an average of 9h and 6min of daylight.
On the first day of the month, sunrise is at 7:06 am and sunset at 4:24 pm. On the last day of December, in Rockton, sunrise is at 7:25 am and sunset at 4:33 pm CST.

Sunshine

In December, the average sunshine is 3.8h.

UV index

The months with the lowest UV index are January and December, with an average maximum UV index of 1. A UV Index of 2, and less, symbolizes a minimal health vulnerability from exposure to the Sun's UV rays for ordinary individuals.
Note: In December, a regular UV index of 1 translates into these guidelines:
Extended time in the sun generally does not harm most, but those with sensitive skin, infants, and children should always be protected. To protect against the Sun's most potent rays, avoid direct exposure around midday. By wearing a generously brimmed hat, you can cut UV radiation exposure significantly. Caution! The reflection of snow can nearly double the intensity of the Sun's UV radiation.
Updated: Feb 12, 2024
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate

Frequently asked questions

How cold is December in Rockton?

December temperatures vary between a high-temperature of 32.4°F (0.2°C) and a low-temperature of 21.7°F (-5.7°C).

What is the average humidity in December in Rockton?

In December, the average relative humidity in Rockton, Illinois, is 83%.

What is the driest month in Rockton?

The months with the least rainfall in Rockton, Illinois, are February and December Rain falls for 5.5 days and accumulates 0.67" (17mm) of rain.

How much does it rain in Rockton in December?

In December, in Rockton, the rain falls for 5.5 days. Throughout December, 0.67" (17mm) of precipitation is accumulated.

How many days does it snow in December in Rockton?

In Rockton, Illinois, in December, snow falls for 8.5 days, with typically accumulated 1.1" (28mm) of snow.

What is the month with the shortest days in Rockton?

The month with the shortest days in Rockton, Illinois, is December, with an average of 9h and 6min of daylight.

What is the average length of the day in December in Rockton?

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

When is the sunrise / sunset in December in Rockton?

In December, on the first day of the month, sunrise is at 7:06 am and sunset at 4:24 pm. On the last day of the month, in Rockton, sunrise is at 7:25 am and sunset at 4:33 pm CST.

How many hours of sunshine does Rockton have in December?

The average sunshine duration in December in Rockton is 3.8h.

When is the lowest UV index in Rockton?

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

What is the UV index intensity in December in Rockton?

The average daily maximum UV index in December in Rockton is 1. A UV Index value of 2, and less, symbolizes a minimal health vulnerability 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
Rockton, IL

Average temperature in December - Rockton, IL
  • Average high temperature in December: 32.4°F

The warmest month (with the highest average high temperature) is July (79.9°F).
The month with the lowest average high temperature is January (25.2°F).

  • Average low temperature in December: 21.7°F

The month with the highest average low temperature is July (62.4°F).
The coldest month (with the lowest average low temperature) is January (12.7°F).

Average pressure in December
Rockton, IL

Average pressure in December - Rockton, IL
  • Average pressure in December: 30.09"Hg

The month with the highest atmospheric pressure is January (30.11"Hg).
The month with the lowest atmospheric pressure is June (29.91"Hg).

Average wind speed in December
Rockton, IL

Average wind speed in December - Rockton, IL
  • Average wind speed in December: 9.3mph

The windiest month (with the highest average wind speed) is April (10.1mph).
The calmest month (with the lowest average wind speed) is August (6.4mph).

Average humidity in December
Rockton, IL

Average humidity in December - Rockton, 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
Rockton, IL

Average rainfall in December - Rockton, IL
  • Average rainfall in December: 0.67"

The wettest month (with the highest rainfall) is June (2.28").
The driest months (with the least rainfall) are February and December (0.67").

Average rainfall days in December
Rockton, IL

Average rainfall days in December - Rockton, IL
  • Average rainfall days in December: 5.5 days

The months with the highest number of rainy days are May and June (15.3 days).
The month with the least rainy days is January (3.1 days).

Average snowfall in December
Rockton, IL

Average snowfall in December - Rockton, IL
  • Average snowfall in December: 1.1"

The month with the highest snowfall is January (2.52").
The months with the least snowfall are May, June, July, August and September (0").

Average snowfall days in December
Rockton, IL

Average snowfall days in December - Rockton, IL
  • Average snowfall days in December: 8.5 days

The month with the highest number of snowfall days is January (11.5 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
Rockton, IL

Average daylight in December / Average sunshine in December - Rockton, 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: 3h and 5min

The months with the most sunshine are July and August (Average sunshine: 9h and 30min).
The months with the least sunshine are January and February (Average sunshine: 3h and 30min).

Average sunshine days in December
Rockton, IL

Average sunshine days in December - Rockton, IL
  • Average sunshine days in December: 17.8 days

The month with the most sunshine days is November (19 days).
The month with the least sunshine days is June (12.8 days).

Average UV index in December
Rockton, IL

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

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

Average cloud cover in December
Rockton, IL

Average cloud cover in December - Rockton, IL
  • 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 September (Cloud cover 35).

Average visibility in December
Rockton, IL

Average visibility in December - Rockton, IL
  • 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).

Rockton, Illinois, USA

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