10-Day Weather Forecast - O'Fallon, IL

Mostly 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 with a slight chance of thunderstorms. A chance of showers mainly in the morning. Highs in the mid 80s. Southwest winds 10 to 15 mph with gusts up to 25 mph. Chance of rain 50 percent.

Mostly cloudy in the evening then becoming partly cloudy. Lows in the upper 60s.

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 showers and thunderstorms. Lows in the upper 60s. Chance of rain 50 percent.

A chance of thunderstorms. Showers likely mainly in the morning. Highs in the mid 80s. Chance of rain 60 percent.

Mostly cloudy. A chance of showers with a slight chance of thunderstorms in the evening then showers likely after midnight. Lows in the mid 60s. Chance of rain 70 percent.

Showers likely with a slight chance of thunderstorms in the morning then partly sunny with a chance of showers and thunderstorms in the afternoon. Highs in the upper 70s. Chance of rain 70 percent.

Partly cloudy in the evening then clearing. A slight chance of thunderstorms in the evening. A chance of showers. Lows in the lower 60s. Chance of rain 50 percent.

Mostly sunny with a chance of showers. A slight chance of thunderstorms in the morning then a chance of thunderstorms in the afternoon. Highs in the lower 80s. Chance of rain 40 percent.

Mostly cloudy with a 70% chance for rain and thunderstorms. Low temperature around 59F. Dew point will be around 59F with an average humidity of 71%. Winds will be 10 mph from the S.

Partly cloudy with a chance of rain. Chance of precipitation 55%. High temperature around 64F. Dew point will be around 46F with an average humidity of 57%. Winds will be 10 mph from the NW.

Clear with a chance of rain. Chance of precipitation 35%. Low temperature around 44F. Dew point will be around 38F with an average humidity of 59%. Winds will be 5 mph from the N.

Sunny. High temperature around 63F. Dew point will be around 38F with an average humidity of 50%. Winds will be 3 mph from the NE.

Clear. Low temperature around 48F. Dew point will be around 41F with an average humidity of 62%. Winds will be 4 mph from the SE.

Partly cloudy. High temperature around 69F. Dew point will be around 47F with an average humidity of 58%. Winds will be 6 mph from the SE.

Partly cloudy. Low temperature around 56F. Dew point will be around 51F with an average humidity of 69%. Winds will be 8 mph from the S.