St. Charles (MO) Rainfall & Precipitation: Monthly Averages and Year-Round Insights

This page shows the average amount of rainfall per month in St. Charles (MO). The numbers are calculated over a 30-year period to provide a reliable average. Let's now guide you through the details for a complete overview.

St. Charles experiences significant rain/snowfall throughout the year, averaging 1114 mm of precipitation annually.

Monthly Precipitation Levels

The average number of days each month with precipitation (> 0.2 mm)

The seasons in St. Charles, bring significant changes in precipitation. The wettest month, April, receives high rainfall, with an average of 128 mm of precipitation.

This rainfall is distributed across 11 rainy days. In contrast, the driest month, January, experiences much less snow/rainfall, totaling 45 mm over 7 snowy/rainy days. These distinct seasonal differences provide diverse experiences throughout the year.

April, the city’s wettest month, has a maximum daytime temperature of 20°C. During the driest month January you can expect a temperature of 5°C. For more detailed insights into the city’s temperatures, visit our St. Charles Temperature page.

Annual Precipitation in the United States of America

The map below shows the annual precipitation across the United States of America. You can also select the different months in case you are interested in a specific month.

Amsterdam Precipitation Compared World Wide

St. Charles’s average annual precipitation is 1114 mm. Let’s compare this to some popular worldwide tourist destinations:

In Lisbon, Portugal, the average annual precipitation is 774 mm, characterized by wet winters and dry summers typical of the Mediterranean climate.

In Shanghai, China, the annual average precipitation is 1347 mm, with a humid subtropical climate.

In Tokyo, Japan, the average annual precipitation is 1528 mm, with significant summer rains due to typhoon season.

Bangkok, Thailand, experiences a tropical monsoon climate with 1668 mm of annual rainfall, with the heaviest precipitation occurring during September and October.

How is Precipitation Measured?

Precipitation amounts are measured using specific gauges installed at weather stations, collecting both rain and snow and any other type of precipitation. Rainfall is measured directly in millimeters, while that from snow and ice is obtained by melting it. Automated systems often incorporate heaters to make this easier.

Information from these stations is transmitted via Wi-Fi, satellite, GPS, or telephone connections to central monitoring networks. This information is immediately updated and integrated into weather models and forecasts.

Interesting weather facts

• "Ginger" was the longest-lasting Atlantic tropical storm, which spun around the open ocean for 28 days in 1971.
• The world's largest snowflake was recorded in the Guinness Book of Records, at 38 cm wide and 20 cm thick. The snowflake fell at Fort Keogh, Montana, USA, on 28 January 1887.
• The greatest snowfall recorded was on Mt. Rainier, Washington State, USA—over 31.5 meters fell during the winter of 1972.

For more detailed information about St. Charles (MO)’s weather, including sunshine hours, humidity levels, and temperature data, visit our St. Charles (MO) Climate page.