O'Fallon Weather in August

During August, O'Fallon experiences very high daytime temperatures of 31°C (88°F) and cooler nights around 20°C (68°F). Expect quite a bit of rainfall. Around 89 mm (3.5 in) is typical.

Rainfall in O'Fallon in August

Analyzing past climate data, one can expect approximately 9 days of rain, averaging 89 mm (3.5 in). Individual showers can be quite heavy this month. A proper umbrella or rain jacket is worth having.

Temperature in O'Fallon in August

Daytime temperatures in O'Fallon reach 31°C (88°F) in August, dropping to 20°C (68°F) at night. For most visitors, the main thing to prepare for is the heat during the day. Nights drop to around 20°C (68°F), which is noticeably cooler than the daytime. A light jacket for the evening is a sensible addition, and the cool nights tend to make sleeping comfortable.

Sunshine in O'Fallon in August

The month enjoys around 268 hours of sunshine, creating mostly sunny days with good weather conditions.

Should you favor a climate that's both dry and comfortably warm, October typically offers the most agreeable circumstances. If you're seeking pleasant, dry and sunny weather somewhere else in the world, our weather planner can help you explore other options.