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Old City Reservoir, IL 7-Day Night Weather Forecast
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Old City Reservoir, IL Weather Forecast
Old City Reservoir, IL Weather Forecast Date: 538 PM CDT Mon Aug 10 2026
The area/counties/county of: Randolph County Il, including the cities of: Chester and Sparta.or toggle through each period.
Tonight... Mostly clear this evening, then becoming partly cloudy. Lows in the mid 70s. South winds 5 to 10 mph. Heat index values up to 105 early this evening.
Tuesday... Sunny, hot with highs in the upper 90s. Southwest winds around 5 mph. Heat index values up to 111.
Tuesday Night... Partly cloudy. Humid with lows in the mid 70s. South winds 5 to 10 mph. Heat index values up to 110 early in the evening.
Wednesday... Mostly sunny. A slight chance of showers and thunderstorms in the afternoon. Hot with highs in the mid 90s. Southwest winds around 5 mph. Chance of rain 20%. Heat index values up to 109.
Wednesday Night... Partly cloudy. Humid with lows in the mid 70s. South winds around 5 mph. Heat index values up to 106 early in the evening.
Thursday... Mostly sunny. A slight chance of showers and thunderstorms in the morning. Hot with highs in the mid 90s. Chance of rain 20%. Heat index values up to 110 in the afternoon.
Thursday Night... Partly cloudy with a slight chance of thunderstorms. A slight chance of showers in the evening, then a chance of showers after midnight. Lows in the mid 70s. Chance of rain 30%. Heat index values up to 105 early in the evening.
Friday... Partly cloudy. Highs in the mid 90s. Lows in the lower 70s. Heat index values up to 105.
Friday Night... Partly cloudy. Highs in the mid 90s. Lows in the lower 70s. Heat index values up to 105.
Saturday... Mostly clear. Hot. Highs in the upper 90s. Lows in the mid 70s. Heat index values up to 105.
Sunday... Mostly clear. Hot. Highs in the upper 90s. Lows in the mid 70s. Heat index values up to 105.
Sunday Night... Mostly clear in the evening, then partly cloudy with a slight chance of showers and thunderstorms after midnight. Lows in the lower 70s. Chance of rain 20%. Heat index values up to 105 early in the evening.
POP = Probability of Precipitation
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