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Grassy Lake, MO Weather Forecast
Grassy Lake, MO Weather Forecast Date: 258 PM CDT Sun Oct 18 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... Clear. Lows around 40. Southeast winds around 5 mph.
Monday... Sunny. Highs in the lower 70s. Southeast winds around 5 mph.
Monday Night... Partly cloudy. Lows in the lower 40s. East winds around 5 mph in the evening, becoming light and variable.
Tuesday... Mostly sunny. Highs in the mid 70s. Light and variable winds, becoming east around 5 mph in the afternoon.
Tuesday Night... Mostly clear. Lows in the mid 40s. Light and variable winds.
Wednesday... Sunny. Highs in the upper 70s.
Wednesday Night... Clear. Lows in the upper 40s. Highs in the upper 70s.
Thursday... Clear. Lows in the upper 40s. Highs in the upper 70s.
Friday... Mostly clear. Highs in the mid 70s. Lows in the upper 40s.
Friday Night... Mostly clear. Highs in the mid 70s. Lows in the upper 40s.
Saturday... Partly cloudy. Highs in the upper 70s. Lows in the lower 50s.
POP = Probability of Precipitation
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