O'Fallon, Missouri Weather:
Saturday, September 12, 2026
Cloudy Weather
Day 82°
Night 59°
Precipitation 1 %
Wind 6 mph
UV Index (0 - 11+) 6
Weather Forecast History
Last Year's Weather on This Day (September 12, 2025)
Cloudy Night

Day

93°

Night

64°

Wind

5 mph

Precipitation

5 %