Average monthly rainy days in O'Fallon (MO)
The number of days each month with rain, snow and hail in O'Fallon (Missouri), the United States of America.
- On average, May is the most rainy with 14 days of rain/snow.
- On average, January is the driest month with 7 rainy days.
- The average annual number of rainy days is 119.
Forecast for O'Fallon (MO)
almost clear and no rain
partly cloudy and chance of rain
partly cloudy and chance of slight rain