10-Day Weather Forecast - O'Fallon, IL

Sunny. Highs in the mid 50s. West winds 5 to 10 mph.

Partly cloudy. Not as cool with lows in the mid 40s. South winds 15 to 20 mph with gusts up to 35 mph.

Partly sunny. Highs in the lower 60s. West winds 10 to 15 mph with gusts up to 30 mph.

Mostly cloudy. Lows in the upper 30s.

Mostly sunny. Highs in the mid 60s.

Mostly cloudy. A slight chance of rain and thunderstorms after midnight. Not as cool with lows in the lower 50s. Chance of rain 20 percent.

Rain likely with a chance of thunderstorms in the morning then rain in the afternoon. Breezy with highs in the mid 60s. Chance of rain 80 percent.

Mostly cloudy with a chance of rain and snow in the evening then partly cloudy after midnight. Breezy and much cooler with lows in the mid 20s. Chance of precipitation 30 percent.

Sunny. Much cooler with highs in the upper 30s.

Partly cloudy in the evening then becoming mostly cloudy. Lows in the lower 20s.

Partly sunny. Highs in the lower 40s.

Cloudy. Low temperature around 33F. Dew point will be around 22F with an average humidity of 61%. Winds will be 9 mph from the S.

Mostly cloudy with a slight chance of rain. Chance of precipitation 25%. High temperature around 58F. Dew point will be around 39F with an average humidity of 67%. Winds will be 8 mph from the S.

Clear. Low temperature around 40F. Dew point will be around 40F with an average humidity of 81%. Winds will be 1 mph from the S.

Sunny. High temperature around 64F. Dew point will be around 44F with an average humidity of 69%. Winds will be 2 mph from the S.

Mostly clear. Low temperature around 48F. Dew point will be around 45F with an average humidity of 74%. Winds will be 4 mph from the S.

Mostly sunny. High temperature around 67F. Dew point will be around 50F with an average humidity of 69%. Winds will be 5 mph from the S.

Mostly clear. Low temperature around 48F. Dew point will be around 47F with an average humidity of 74%. Winds will be 2 mph from the S.