Weather Forecast and Radar for O'Fallon, Missouri

Weather in O'Fallon, MO

O'Fallon, Missouri experiences four distinct seasons annually. In the summer months, temperatures usually reach the high 80s and sometimes near 90 degrees Fahrenheit. The humidity levels are usually high due to the close proximity of the Mississippi River. Winters in O'Fallon can be quite cold, with temperatures usually dropping into the mid-20s and even occasionally reaching below zero. Snowfall is not uncommon during this time of year. Spring and fall in O'Fallon are generally mild with temperatures ranging from the mid-50s to the low 70s. Rainfall is common throughout the year, but especially during the spring and fall months.

Fast Facts About O'Fallon, MO

As of 2020, the city population is 88132.

Major Cities Nearby O'Fallon, MO

This map shows the current & 7-day weather forecast, weather alerts, and weather radar for O'Fallon, Missouri.