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Big Flat Lake, IL Weather Forecast
Big Flat Lake, IL Weather Forecast Date: 444 PM CDT Wed Oct 28 2026
The area/counties/county of: Clinton County Il, including the cities of: Centralia and Salem.or toggle through each period.
Tonight... Clear. Lows in the lower 50s. South winds around 5 mph.
Thursday... Sunny. Highs in the lower 80s. Southwest winds 5 to 10 mph.
Thursday Night... Partly cloudy in the evening, then becoming mostly cloudy. Lows in the mid 50s. Southwest winds around 5 mph, becoming northeast after midnight.
Friday... Partly sunny. Highs in the upper 70s. East winds around 5 mph.
Friday Night... Mostly cloudy. Lows in the mid 50s. Southeast winds around 5 mph.
Saturday... Mostly cloudy. Highs in the mid 70s.
Saturday Night... Mostly cloudy. A chance of showers after midnight. Lows in the mid 50s. Chance of rain 30%.
Sunday... Mostly cloudy. A chance of showers, mainly in the morning. Highs in the upper 60s. Chance of rain 40%.
Sunday Night... Mostly cloudy with a 20% chance of showers. Lows in the mid 50s.
Monday... Mostly cloudy. A slight chance of showers in the morning, then a chance of showers in the afternoon. Highs around 70. Chance of rain 30%.
Monday Night... Mostly cloudy with a chance of showers. A slight chance of thunderstorms after midnight. Lows in the upper 50s. Chance of rain 40%.
Tuesday... Mostly cloudy with a chance of showers with a slight chance of thunderstorms. Highs in the lower 70s. Lows in the mid 50s. Chance of rain 50%.
POP = Probability of Precipitation
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