10-Day Weather Forecast - O'Fallon, IL

Partly sunny in the morning then mostly cloudy with a chance of showers in the afternoon. Highs in the lower 80s. South winds 15 to 20 mph with gusts up to 30 mph. Chance of rain 50 percent.

Showers likely with a chance of thunderstorms. Lows in the mid 60s. South winds 15 to 20 mph. Chance of rain 70 percent.

Mostly sunny. A chance of showers with a slight chance of thunderstorms in the morning. Highs in the mid 80s. Southwest winds 15 to 20 mph with gusts up to 30 mph. Chance of rain 50 percent.

Mostly cloudy in the evening then becoming partly cloudy. Lows in the upper 60s. South winds 10 to 15 mph with gusts up to 25 mph.

Mostly sunny. A chance of showers and thunderstorms in the afternoon. Highs in the upper 80s. Chance of rain 30 percent.

Mostly cloudy with a chance of thunderstorms. A chance of showers in the evening then showers likely after midnight. Lows in the upper 60s. Chance of rain 60 percent.

Showers likely with a chance of thunderstorms. Highs in the lower 80s. Lows in the lower 60s. Chance of rain 70 percent.

Showers likely with a chance of thunderstorms. Highs in the lower 80s. Lows in the lower 60s. Chance of rain 70 percent.

Partly sunny with a chance of showers with a slight chance of thunderstorms. Highs in the lower 80s. Chance of rain 50 percent.

Mostly clear with a 20 percent chance of showers. Lows in the lower 60s.

Partly sunny. A slight chance of showers in the morning then a chance of showers with a slight chance of thunderstorms in the afternoon. Highs in the mid 80s. Chance of rain 50 percent.

Showers likely with a slight chance of thunderstorms. Lows in the mid 50s. Chance of rain 60 percent.

Mostly cloudy in the morning then becoming partly sunny. A chance of showers. A slight chance of thunderstorms in the afternoon. Much cooler with highs in the upper 60s. Chance of rain 50 percent.

Partly cloudy with a chance of rain. Chance of precipitation 40%. Low temperature around 52F. Dew point will be around 44F with an average humidity of 63%. Winds will be 4 mph from the E.

Mostly sunny. High temperature around 66F. Dew point will be around 46F with an average humidity of 58%. Winds will be 4 mph from the E.

Clear. Low temperature around 52F. Dew point will be around 46F with an average humidity of 66%. Winds will be 4 mph from the SE.

Partly cloudy. High temperature around 69F. Dew point will be around 52F with an average humidity of 65%. Winds will be 6 mph from the SE.

Partly cloudy. Low temperature around 58F. Dew point will be around 52F with an average humidity of 70%. Winds will be 6 mph from the S.