O'Fallon Weather in April

The climate in O'Fallon during April can be summarized as mild and a little damp.

April is in the spring in O'Fallon and is typically the 6th coldest month of the year. Daytime maximum temperatures average around 19°C (67°F), whilst at night 7°C (45°F) is normal.

On average April is the 2nd wettest month of the year in O'Fallon with around 96mm 3.8 inches of rain making it a a little damp time to visit. This rainfall is typically spread over 11 days, although this may vary considerably.

On the flip side this corresponds to an average of 8 hours of sunshine per day.

The data used in these monthly averages covers a period of over 100 years right up until last year. As such they are a valid prediction of what to expect for the weather in O'Fallon in April 2025.