2025 Compare Climate & Weather:
St. Charles, IL vs St. John, IN

Highlights

On average, there are 187 sunny days per year in St. John. St. Charles averages 189 sunny days per year. The US average is 205 sunny days.

St. John, Indiana gets 39 inches of rain, on average, per year. St. Charles, Illinois gets 37.7 inches of rain, on average, per year. The US average is 38.1 inches of rain per year.

St. John averages 28.2 inches of snow per year. St. Charles averages 30.1 inches of snow per year. The US average is 27.8 inches of snow per year.

Weather Highlights

St. John, Indiana
Summer High: the July high is around 83.7 degrees
Winter Low: the January low is 15.6
Rain: averages 39 inches of rain a year
Snow: averages 28.2 inches of snow a year

St. Charles, Illinois
Summer High: the July high is around 84.5 degrees
Winter Low: the January low is 14.7
Rain: averages 37.7 inches of rain a year
Snow: averages 30.1 inches of snow a year

BestPlaces Comfort Index

The annual BestPlaces Comfort Index for St. John is 6.9 (10=best), which means it is less comfortable than most places in Indiana.

The annual BestPlaces Comfort Index for St. Charles is 6.9 (10=best), which means it is less comfortable than most places in Illinois.

Today's Weather - St. Charles, IL

57°F

Today's Weather - St. John, IN

49°F

Average Monthly High / Low (°F)

Hot, Freezing, Rainy, Snowy Days: St. Charles / St. John

July is the hottest month for St. Charles with an average high temperature of 84.5°, which ranks it as cooler than most places in Illinois. In St. Charles, there are 5 comfortable months with high temperatures in the range of 70-85°. The most pleasant months of the year for St. Charles are September, June and August.

July is the hottest month for St. John with an average high temperature of 83.7°, which ranks it as cooler than most places in Indiana. In St. John, there are 5 comfortable months with high temperatures in the range of 70-85°. The most pleasant months of the year for St. John are September, June and August.

January has the coldest nighttime temperatures for St. Charles with an average of 14.7°. This is colder than most places in Illinois.

January has the coldest nighttime temperatures for St. John with an average of 15.6°. This is one of the coldest places in Indiana.

In St. Charles, there are 13.8 days annually when the high temperature is over 90°, which is cooler than most places in Illinois.

In St. John, there are 13.1 days annually when the high temperature is over 90°, which is about average compared to other places in Indiana.

In St. Charles, there are 131.8 days annually when the nighttime low temperature falls below freezing, which is colder than most places in Illinois.

In St. John, there are 128.2 days annually when the nighttime low temperature falls below freezing, which is colder than most places in Indiana.

In St. Charles, there are 8.8 days annually when the nighttime low temperature falls below zero°, which is colder than most places in Illinois.

In St. John, there are 8.7 days annually when the nighttime low temperature falls below zero°, which is one of the coldest places in Indiana.

August is the wettest month in St. Charles with 4.7 inches of rain, and the driest month is January with 1.6 inches. The wettest season is Autumn with 34% of yearly precipitation and 14% occurs in Spring, which is the driest season. The annual rainfall of 37.7 inches in St. Charles means that it is drier than most places in Illinois.


August is the wettest month in St. John with 4.6 inches of rain, and the driest month is February with 1.8 inches. The wettest season is Autumn with 33% of yearly precipitation and 17% occurs in Spring, which is the driest season. The annual rainfall of 39.0 inches in St. John means that it is drier than most places in Indiana.

May is the rainiest month in St. Charles with 12.2 days of rain, and February is the driest month with only 7.7 rainy days. There are 119.6 rainy days annually in St. Charles, which is rainier than most places in Illinois. The rainiest season is Summer when it rains 28% of the time and the driest is Spring with only a 23% chance of a rainy day.

May is the rainiest month in St. John with 11.6 days of rain, and February is the driest month with only 8.4 rainy days. There are 118.5 rainy days annually in St. John, which is about average compared to other places in Indiana. The rainiest season is Summer when it rains 28% of the time and the driest is Autumn with only a 24% chance of a rainy day.

An annual snowfall of 30.1 inches in St. Charles means that it is snowier than most places in Illinois.

An annual snowfall of 28.2 inches in St. John means that it is snowier than most places in Indiana.

January is the snowiest month in St. Charles with 9.6 inches of snow, and 6 months of the year have significant snowfall.

January is the snowiest month in St. John with 8.5 inches of snow, and 6 months of the year have significant snowfall.