2025 Compare Climate & Weather:
Charleston, IL vs Riverside, CA

Highlights

On average, there are 277 sunny days per year in Riverside. Charleston averages 202 sunny days per year. The US average is 205 sunny days.

Riverside, California gets 11.3 inches of rain, on average, per year. Charleston, Illinois gets 40.3 inches of rain, on average, per year. The US average is 38.1 inches of rain per year.

Riverside averages 0 inches of snow per year. Charleston averages 15.1 inches of snow per year. The US average is 27.8 inches of snow per year.

Weather Highlights

Riverside, California
Summer High: the July high is around 94.2 degrees
Winter Low: the January low is 42.4
Rain: averages 11.3 inches of rain a year
Snow: averages 0 inches of snow a year

Charleston, Illinois
Summer High: the July high is around 86.2 degrees
Winter Low: the January low is 20.2
Rain: averages 40.3 inches of rain a year
Snow: averages 15.1 inches of snow a year

BestPlaces Comfort Index

The annual BestPlaces Comfort Index for Riverside is 8.7 (10=best), which means it is more comfortable than most places in California.

The annual BestPlaces Comfort Index for Charleston is 7.2 (10=best), which means it is one of the most pleasant places in Illinois.

Today's Weather - Charleston, IL

58°F

Today's Weather - Riverside, CA

59°F

Average Monthly High / Low (°F)

Hot, Freezing, Rainy, Snowy Days: Charleston / Riverside

July is the hottest month for Charleston with an average high temperature of 86.2°, which ranks it as warmer than most places in Illinois. In Charleston, there are 3 comfortable months with high temperatures in the range of 70-85°. The most pleasant months of the year for Charleston are September, May and June.

August is the hottest month for Riverside with an average high temperature of 95.4°, which ranks it as warmer than most places in California. In Riverside, there are 5 comfortable months with high temperatures in the range of 70-85°. The most pleasant months of the year for Riverside are April, May and November.

January has the coldest nighttime temperatures for Charleston with an average of 20.2°. This is warmer than most places in Illinois.

December has the coldest nighttime temperatures for Riverside with an average of 41.3°. This is warmer than most places in California.

In Charleston, there are 20.6 days annually when the high temperature is over 90°, which is about average compared to other places in Illinois.

In Riverside, there are 95.9 days annually when the high temperature is over 90°, which is hotter than most places in California.

In Charleston, there are 103.6 days annually when the nighttime low temperature falls below freezing, which is warmer than most places in Illinois.

In Riverside, there are 4.4 days annually when the nighttime low temperature falls below freezing, which is warmer than most places in California.

In Charleston, there are 3.9 days annually when the nighttime low temperature falls below zero°, which is warmer than most places in Illinois.

In Riverside, there are 0.0 days annually when the nighttime low temperature falls below zero°, which is about average compared to other places in California.

May is the wettest month in Charleston with 4.4 inches of rain, and the driest month is February with 2.1 inches. The wettest season is Autumn with 29% of yearly precipitation and 18% occurs in Spring, which is the driest season. The annual rainfall of 40.3 inches in Charleston means that it is wetter than most places in Illinois.


February is the wettest month in Riverside with 2.7 inches of rain, and the driest month is June with 0.1 inches. The wettest season is Spring with 59% of yearly precipitation and 3% occurs in Autumn, which is the driest season. The annual rainfall of 11.3 inches in Riverside means that it is drier than most places in California.

May is the rainiest month in Charleston with 11.7 days of rain, and September is the driest month with only 7.0 rainy days. There are 111.3 rainy days annually in Charleston, which is rainier than most places in Illinois. The rainiest season is Summer when it rains 30% of the time and the driest is Winter with only a 23% chance of a rainy day.

February is the rainiest month in Riverside with 6.2 days of rain, and August is the driest month with only 0.4 rainy days. There are 34.0 rainy days annually in Riverside, which is less rainy than most places in California. The rainiest season is Spring when it rains 48% of the time and the driest is Autumn with only a 5% chance of a rainy day.

An annual snowfall of 15.1 inches in Charleston means that it is less snowy than most places in Illinois.

There is rarely any recorded snowfall in Riverside, ranking it as one of the least snowy places in California.

January is the snowiest month in Charleston with 6.2 inches of snow, and 4 months of the year have significant snowfall.

Any measurable snowfall is a rare occurance in Riverside.