December weather forecast
Riverside, IL

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Weather in December

December, the first month of the winter in Riverside, is also an icy month, with temperature in the range of an average low of 26.4°F (-3.1°C) and an average high of 35.1°F (1.7°C).

Temperature

A moderate decline in the average high-temperature is seen during December, decreasing from a chilly 46°F (7.8°C) in November to a cold 35.1°F (1.7°C). Riverside reports an average low-temperature of 26.4°F (-3.1°C) during the subtly cooler December nights.

Humidity

In December, the average relative humidity is 80%.

Rainfall

February, March, November and December are months with the least rain when the rain falls for 4.3 days and typically aggregates up to 0.39" (10mm) of rain.

Snowfall

Months with snowfall in Riverside are January through April, October through December. In Riverside, in December, during 4.5 snowfall days, 0.28" (7mm) of snow is typically accumulated. Throughout the year, in Riverside, there are 26.5 snowfall days, and 4.06" (103mm) of snow is accumulated.

Daylight

With an average of 9h and 12min of daylight, December has the shortest days of the year.
On the first day of December, sunrise is at 6:59 am and sunset at 4:21 pm. On the last day of the month, sunrise is at 7:18 am and sunset at 4:30 pm CST.

Sunshine

The average sunshine in December in Riverside 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 estimate of 2, and below, represents a low threat to health from exposure to the Sun's UV radiation for average individuals.
Note: In December, an average UV index of 1 transforms into the following instructions:
Prolonged sun exposure should always be prevented in babies, children, and those with sensitive skin. Avoiding direct sunlight during midday hours helps reduce the risk from intense UV radiation. A hat with a broad brim is indispensable, filtering out up to half of UV rays. Take into account! The reflection from snow can nearly double the Sun's UV radiation intensity.
Updated: Feb 12, 2024
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate

Frequently asked questions

How cold is it in Riverside in December?

The high-temperature, in December, in Riverside, records 35.1°F (1.7°C), while the low-temperature is 26.4°F (-3.1°C).

What is the average humidity in December in Riverside?

In Riverside, the average relative humidity in December is 80%.

What is the driest month in Riverside?

February, March, November and December are months with the least rain when the rain falls for 4.3 days and typically aggregates up to 0.39" (10mm) of rain.

How many days does it rain in December in Riverside?

In December, the rain falls for 4.3 days. Throughout December, 0.39" (10mm) of precipitation is accumulated.

How much does it snow in Riverside in December?

In Riverside, Illinois, during December, snow falls for 4.5 days and regularly aggregates up to 0.28" (7mm) of snow.

What is the month with the shortest days in Riverside?

December has the shortest days of the year in Riverside, Illinois, with an average of 9h and 12min of daylight.

How many hours of daylight does Riverside have in December?

The average day length in December is 9h and 12min.

When is the sunrise / sunset in December in Riverside?

In December, on the first day of the month, sunrise is at 6:59 am and sunset at 4:21 pm. On the last day of the month, sunrise is at 7:18 am and sunset at 4:30 pm CST.

How many hours of sunshine does Riverside have in December?

The average sunshine duration in December in Riverside, Illinois, is 4.1h.

What are the months with the lowest UV index in Riverside?

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

What is the UV index reading in December in Riverside?

In Riverside, the average daily maximum UV index in December is 1. A UV Index reading 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
Riverside, IL

Average temperature in December - Riverside, IL
  • Average high temperature in December: 35.1°F

The warmest month (with the highest average high temperature) is July (80.4°F).
The month with the lowest average high temperature is January (29.1°F).

  • Average low temperature in December: 26.4°F

The month with the highest average low temperature is July (67.1°F).
The coldest month (with the lowest average low temperature) is January (19.2°F).

Average pressure in December
Riverside, IL

Average pressure in December - Riverside, 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 (29.92"Hg).

Average wind speed in December
Riverside, IL

Average wind speed in December - Riverside, IL
  • Average wind speed in December: 10.3mph

The windiest month (with the highest average wind speed) is January (10.9mph).
The calmest month (with the lowest average wind speed) is August (6.8mph).

Average humidity in December
Riverside, IL

Average humidity in December - Riverside, IL
  • Average humidity in December: 80%

The months with the highest relative humidity are January and February (82%).
The month with the lowest relative humidity is October (72%).

Average rainfall in December
Riverside, IL

Average rainfall in December - Riverside, IL
  • Average rainfall in December: 0.39"

The wettest month (with the highest rainfall) is May (1.1").
The driest months (with the least rainfall) are February, March, November and December (0.39").

Average rainfall days in December
Riverside, IL

Average rainfall days in December - Riverside, IL
  • Average rainfall days in December: 4.3 days

The month with the highest number of rainy days is June (11.7 days).
The month with the least rainy days is January (3.1 days).

Average snowfall in December
Riverside, IL

Average snowfall in December - Riverside, IL
  • Average snowfall in December: 0.28"

The month with the highest snowfall is February (1.38").
The months with the least snowfall are May, June, July, August and September (0").

Average snowfall days in December
Riverside, IL

Average snowfall days in December - Riverside, IL
  • Average snowfall days in December: 4.5 days

The month with the highest number of snowfall days is February (7.3 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
Riverside, IL

Average daylight in December / Average sunshine in December - Riverside, 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 12min).

  • Average sunshine in December: 4h and 1min

The month with the most sunshine is August (Average sunshine: 10h and 36min).
The month with the least sunshine is January (Average sunshine: 3h and 48min).

Average sunshine days in December
Riverside, IL

Average sunshine days in December - Riverside, IL
  • Average sunshine days in December: 23.7 days

The month with the most sunshine days is December (23.7 days).
The month with the least sunshine days is June (14.3 days).

Average UV index in December
Riverside, IL

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

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

Average cloud cover in December
Riverside, IL

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

The month with the most cloud cover is January (Cloud cover 61).
The month with the least cloud cover is August (Cloud cover 27).

Average visibility in December
Riverside, IL

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

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

Riverside, Illinois, USA

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