2025 Compare Climate & Weather:
Sioux City, IA vs St. Louis, MO

Highlights

On average, there are 202 sunny days per year in St. Louis. Sioux City averages 210 sunny days per year. The US average is 205 sunny days.

St. Louis, Missouri gets 42.2 inches of rain, on average, per year. Sioux City, Iowa gets 29.5 inches of rain, on average, per year. The US average is 38.1 inches of rain per year.

St. Louis averages 15.5 inches of snow per year. Sioux City averages 32.3 inches of snow per year. The US average is 27.8 inches of snow per year.

Weather Highlights

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

Sioux City, Iowa
Summer High: the July high is around 85.5 degrees
Winter Low: the January low is 9.6
Rain: averages 29.5 inches of rain a year
Snow: averages 32.3 inches of snow a year

BestPlaces Comfort Index

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

The annual BestPlaces Comfort Index for Sioux City is 7.0 (10=best), which means it is more comfortable than most places in Iowa.

Today's Weather - Sioux City, IA

68°F

Today's Weather - St. Louis, MO

56°F

Average Monthly High / Low (°F)

Hot, Freezing, Rainy, Snowy Days: Sioux City / St. Louis

July is the hottest month for Sioux City with an average high temperature of 85.5°, which ranks it as warmer than most places in Iowa. In Sioux City, there are 4 comfortable months with high temperatures in the range of 70-85°. The most pleasant months of the year for Sioux City are September, June and August.

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.

January has the coldest nighttime temperatures for Sioux City with an average of 9.6°. This is about average compared to other places in Iowa.

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

In Sioux City, there are 19.8 days annually when the high temperature is over 90°, which is one of the hottest places in Iowa.

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 Sioux City, there are 155.6 days annually when the nighttime low temperature falls below freezing, which is colder than most places in Iowa.

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 Sioux City, there are 18.9 days annually when the nighttime low temperature falls below zero°, which is about average compared to other places in Iowa.

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.

June is the wettest month in Sioux City with 4.1 inches of rain, and the driest month is February with 0.7 inches. The wettest season is Autumn with 37% of yearly precipitation and 8% occurs in Spring, which is the driest season. The annual rainfall of 29.5 inches in Sioux City means that it is one of the driest places in Iowa.


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.

May is the rainiest month in Sioux City with 10.3 days of rain, and February is the driest month with only 4.1 rainy days. There are 83.7 rainy days annually in Sioux City, which is one of the least rainy places in Iowa. The rainiest season is Summer when it rains 31% of the time and the driest is Spring with only a 16% chance of a rainy day.

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.

An annual snowfall of 32.3 inches in Sioux City means that it is snowier than most places in Iowa.

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

December is the snowiest month in Sioux City with 7.3 inches of snow, and 6 months of the year have significant snowfall.

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