10-Day Weather Forecast - O'Fallon, MO

Sunny. Much cooler with highs in the upper 30s. Northwest winds 15 to 20 mph with gusts up to 35 mph becoming southwest 5 to 10 mph in the afternoon.

Mostly clear in the evening then becoming partly cloudy. Near steady temperature in the lower 30s. South winds 10 to 15 mph with gusts up to 25 mph.

Mostly sunny. Not as cool with highs in the mid 50s. South winds 10 to 15 mph becoming west in the afternoon.

Partly cloudy. Lows in the upper 20s. Northwest winds 5 to 10 mph.

Partly cloudy. Highs in the lower 40s. Lows in the upper 20s.

Partly cloudy. Highs in the lower 40s. Lows in the upper 20s.

Mostly cloudy. Highs in the upper 40s. Lows around 40.

Mostly cloudy. Highs in the upper 40s. Lows around 40.

Mostly sunny. Not as cool with highs in the lower 60s.

Mostly cloudy. Lows in the upper 40s. Highs in the upper 60s.

Mostly cloudy. Lows in the upper 40s. Highs in the upper 60s.

Mostly cloudy. Lows in the mid 50s.

Mostly sunny. Highs in the upper 60s.

Mostly clear. Low temperature around 53F. Dew point will be around 54F with an average humidity of 83%. Winds will be 6 mph from the SW.

Mostly sunny. High temperature around 62F. Dew point will be around 51F with an average humidity of 75%. Winds will be 5 mph from the SW.

Partly cloudy. Low temperature around 50F. Dew point will be around 49F with an average humidity of 83%. Winds will be 2 mph from the S.

Mostly cloudy. High temperature around 59F. Dew point will be around 49F with an average humidity of 79%. Winds will be 1 mph from the S.

Cloudy with a slight chance of rain. Chance of precipitation 25%. Low temperature around 47F. Dew point will be around 46F with an average humidity of 83%. Winds will be 2 mph from the NE.