Weather WorldKaty Reservoir, MO 7-Day Night Weather Forecast
Quick Weather Clicks
Settings
Sun & Moon
Weather Quote O' the Day
Katy Reservoir, MO Weather Forecast
Katy Reservoir, MO Weather Forecast Date: 943 PM CDT Tue Sep 29 2026
The area/counties/county of: Madison County Il, including the cities of: Alton, Edwardsville, Belleville, Cahokia, Saint Charles, and Saint Louis.or toggle through each period.
Tonight... Mostly cloudy. Not as cool with lows in the mid 60s. Southeast winds around 5 mph.
Wednesday... Mostly cloudy in the morning, then becoming partly sunny. Highs in the upper 80s. South winds 5 to 10 mph with gusts up to 20 mph.
Wednesday Night... Mostly cloudy. Lows in the lower 70s. South winds 5 to 10 mph with gusts up to 20 mph.
Thursday... Mostly cloudy. 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 upper 80s. South winds 10 to 15 mph. Chance of rain 50%.
Thursday Night... Cloudy with a slight chance of thunderstorms. A chance of showers in the evening, then showers after midnight. Lows in the upper 60s. Southwest winds 5 to 10 mph, becoming west after midnight. Chance of rain 90%.
Friday... Showers likely with a slight chance of thunderstorms in the morning, then a chance of showers in the afternoon. Much cooler with highs in the lower 70s. Chance of rain 70%.
Friday Night... Mostly cloudy with a 20% chance of showers. Lows in the mid 50s. Highs in the upper 60s.
Saturday... Mostly cloudy with a 20% chance of showers. Lows in the mid 50s. Highs in the upper 60s.
Sunday... Mostly clear. Highs around 70. Lows around 50.
Monday... Mostly clear. Highs around 70. Lows around 50.
POP = Probability of Precipitation
Katy Reservoir Radar Loop
Use the map search tool if you want to place a location marker on the radar map...