2025 Compare Climate & Weather:
St. Louis, MO vs Joliet, IL

Highlights

On average, there are 186 sunny days per year in Joliet. St. Louis averages 202 sunny days per year. The US average is 205 sunny days.

Joliet, Illinois gets 39 inches of rain, on average, per year. St. Louis, Missouri gets 42.2 inches of rain, on average, per year. The US average is 38.1 inches of rain per year.

Joliet averages 27.7 inches of snow per year. St. Louis averages 15.5 inches of snow per year. The US average is 27.8 inches of snow per year.

Weather Highlights

Joliet, Illinois
Summer High: the July high is around 84.3 degrees
Winter Low: the January low is 16
Rain: averages 39 inches of rain a year
Snow: averages 27.7 inches of snow a year

St. Louis, Missouri
Summer High: the July high is around 88.5 degrees
Winter Low: the January low is 22.8
Rain: averages 42.2 inches of rain a year
Snow: averages 15.5 inches of snow a year

BestPlaces Comfort Index

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

The annual BestPlaces Comfort Index for St. Louis is 7.2 (10=best), which means it is more comfortable than most places in Missouri.

Today's Weather - St. Louis, MO

74°F

Today's Weather - Joliet, IL

65°F

Average Monthly High / Low (°F)

Hot, Freezing, Rainy, Snowy Days: St. Louis / Joliet

July is the hottest month for St. Louis with an average high temperature of 88.5°, which ranks it as about average compared to other places in Missouri. In St. Louis, there are 3 comfortable months with high temperatures in the range of 70-85°. The most pleasant months of the year for St. Louis are May, September and June.

July is the hottest month for Joliet with an average high temperature of 84.3°, which ranks it as cooler than most places in Illinois. In Joliet, there are 5 comfortable months with high temperatures in the range of 70-85°. The most pleasant months of the year for Joliet are September, June and August.

January has the coldest nighttime temperatures for St. Louis with an average of 22.8°. This is warmer than most places in Missouri.

January has the coldest nighttime temperatures for Joliet with an average of 16.0°. This is about average compared to other places in Illinois.

In St. Louis, there are 36.0 days annually when the high temperature is over 90°, which is hotter than most places in Missouri.

In Joliet, there are 12.5 days annually when the high temperature is over 90°, which is cooler than most places in Illinois.

In St. Louis, there are 91.1 days annually when the nighttime low temperature falls below freezing, which is warmer than most places in Missouri.

In Joliet, there are 123.2 days annually when the nighttime low temperature falls below freezing, which is about average compared to other places in Illinois.

In St. Louis, there are 1.5 days annually when the nighttime low temperature falls below zero°, which is warmer than most places in Missouri.

In Joliet, there are 7.1 days annually when the nighttime low temperature falls below zero°, which is about average compared to other places in Illinois.

May is the wettest month in St. Louis with 4.8 inches of rain, and the driest month is February with 2.3 inches. The wettest season is Summer with 29% of yearly precipitation and 18% occurs in Spring, which is the driest season. The annual rainfall of 42.2 inches in St. Louis means that it is drier than most places in Missouri.


July is the wettest month in Joliet with 4.6 inches of rain, and the driest month is January with 1.8 inches. The wettest season is Autumn with 33% of yearly precipitation and 15% occurs in Spring, which is the driest season. The annual rainfall of 39.0 inches in Joliet means that it is about average compared to other places in Illinois.

May is the rainiest month in St. Louis with 11.3 days of rain, and September is the driest month with only 7.0 rainy days. There are 105.3 rainy days annually in St. Louis, which is rainier than most places in Missouri. The rainiest season is Summer when it rains 30% of the time and the driest is Spring with only a 23% chance of a rainy day.

May is the rainiest month in Joliet with 12.4 days of rain, and September is the driest month with only 7.8 rainy days. There are 124.6 rainy days annually in Joliet, which is one of the rainiest places in Illinois. The rainiest season is Summer when it rains 28% of the time and the driest is Winter with only a 22% chance of a rainy day.

An annual snowfall of 15.5 inches in St. Louis means that it is snowier than most places in Missouri.

An annual snowfall of 27.7 inches in Joliet means that it is snowier than most places in Illinois.

January is the snowiest month in St. Louis with 4.9 inches of snow, and 5 months of the year have significant snowfall.

December is the snowiest month in Joliet with 8.6 inches of snow, and 5 months of the year have significant snowfall.