Big Flat Lake, IL Weather Forecast & Current Conditions

Night: Partly cloudy. Lows in the lower 70s. South winds around 5 mph.

Day: Mostly sunny. Highs in the mid 90s. West winds around 5 mph.

Night: Mostly cloudy with a chance of thunderstorms. A chance of showers in the evening, then showers likely after midnight. Lows in the upper 60s. North winds around 5 mph. Chance of rain 70 percent.

Day: Mostly cloudy with a chance of showers. A chance of thunderstorms, mainly in the morning. Cooler with highs in the lower 80s. Northeast winds 5 to 10 mph. Chance of rain 40 percent.

Night: Mostly cloudy with a chance of showers with a slight chance of thunderstorms. Lows around 60. Northeast winds 5 to 10 mph. Chance of rain 50 percent.

Day: Mostly cloudy with a slight chance of showers in the morning, then partly sunny in the afternoon. Highs in the lower 70s. Chance of rain 20 percent.

Night: Mostly cloudy in the evening, then becoming partly cloudy. Lows in the mid 50s.

Night: Partly cloudy. Highs in the mid 70s. Lows in the mid 50s.

Day: Partly sunny. Highs in the mid 70s.

Night: Mostly cloudy. A 20 percent chance of showers. Lows in the upper 50s. Highs in the upper 70s.

Night: Partly cloudy. Lows in the upper 50s. Highs in the lower 80s.

Night: Partly cloudy. Lows in the lower 70s. South winds around 5 mph.

Day: Mostly sunny. Highs in the mid 90s. West winds around 5 mph.

Night: Mostly cloudy with a chance of thunderstorms. A chance of showers in the evening, then showers likely after midnight. Lows in the upper 60s. North winds around 5 mph. Chance of rain 70 percent.

Day: Mostly cloudy with a chance of showers. A chance of thunderstorms, mainly in the morning. Cooler with highs in the lower 80s. Northeast winds 5 to 10 mph. Chance of rain 40 percent.

Night: Mostly cloudy with a chance of showers with a slight chance of thunderstorms. Lows around 60. Northeast winds 5 to 10 mph. Chance of rain 50 percent.

Day: Mostly cloudy with a slight chance of showers in the morning, then partly sunny in the afternoon. Highs in the lower 70s. Chance of rain 20 percent.

Night: Mostly cloudy in the evening, then becoming partly cloudy. Lows in the mid 50s.

Night: Partly cloudy. Highs in the mid 70s. Lows in the mid 50s.

Day: Partly sunny. Highs in the mid 70s.

Night: Mostly cloudy. A 20 percent chance of showers. Lows in the upper 50s. Highs in the upper 70s.

Night: Partly cloudy. Lows in the upper 50s. Highs in the lower 80s.

Night: Partly cloudy. Near steady temperature in the mid 70s. Southwest winds around 5 mph.

Day: Partly sunny. Highs in the lower 90s. West winds 5 to 10 mph.

Night: Showers likely with a chance of thunderstorms. Lows in the upper 60s. North winds 5 to 10 mph. Chance of rain 70 percent.

Day: Mostly cloudy with a chance of showers with a slight chance of thunderstorms. Cooler with highs in the upper 70s. Northeast winds 5 to 10 mph. Chance of rain 50 percent.

Night: Mostly cloudy. A chance of showers with a slight chance of thunderstorms in the evening, then a slight chance of showers after midnight. Lows around 60. Northeast winds 5 to 10 mph. Chance of rain 50 percent.

Night: Mostly cloudy. Highs in the lower 70s. Lows in the mid 50s.

Night: Partly cloudy. Highs in the lower 70s. Lows in the mid 50s.

Day: Partly sunny. Highs in the mid 70s.

Night: Mostly cloudy. A 20 percent chance of showers. Lows in the upper 50s. Highs in the upper 70s.

Night: Partly cloudy. Lows in the upper 50s. Highs in the lower 80s.

Night: Partly cloudy. Near steady temperature in the mid 70s. South winds around 5 mph.

Day: Partly sunny. A slight chance of showers and thunderstorms in the afternoon. Highs in the lower 90s. Northwest winds around 5 mph. Chance of rain 20 percent.

Night: Mostly cloudy with a chance of thunderstorms. A chance of showers in the evening, then showers likely after midnight. Lows in the mid 60s. Northeast winds 5 to 10 mph. Chance of rain 70 percent.

Day: Mostly cloudy with a chance of showers. A slight chance of thunderstorms in the afternoon. Cooler with highs in the upper 70s. Northeast winds 5 to 10 mph. Chance of rain 50 percent.

Night: A slight chance of thunderstorms in the evening. Mostly cloudy with a chance of showers. Lows in the upper 50s. Northeast winds 5 to 10 mph. Chance of rain 50 percent.

Day: Mostly cloudy with a slight chance of showers in the morning, then partly sunny in the afternoon. Highs in the lower 70s. Chance of rain 20 percent.

Night: Mostly cloudy. Lows in the lower 50s.

Night: Partly cloudy. Highs in the lower 70s. Lows in the lower 50s.

Day: Partly sunny. Highs in the mid 70s.

Night: Mostly cloudy. A 20 percent chance of showers. Lows in the mid 50s. Highs in the upper 70s.

Night: Partly cloudy. Lows in the mid 50s. Highs around 80.

Night: Partly cloudy this evening, then clearing. Lows in the lower 70s. South winds around 5 mph.

Day: Mostly sunny. Hot with highs in the mid 90s. West winds 5 to 10 mph.

Night: Partly cloudy in the evening, then becoming mostly cloudy. A chance of showers and thunderstorms. Lows in the upper 60s. North winds around 5 mph. Chance of rain 50 percent.

Day: Mostly cloudy in the morning, then becoming partly sunny. A chance of thunderstorms in the morning. A chance of showers. Highs in the mid 80s. Northeast winds 5 to 10 mph. Chance of rain 50 percent.

Night: Mostly cloudy. A chance of showers after midnight. Lows around 60. Northeast winds 5 to 10 mph. Chance of rain 50 percent.

Day: Partly sunny. Highs in the mid 70s.

Night: Partly cloudy. Lows in the mid 50s. Highs in the mid 70s.

Night: Partly cloudy. Lows in the mid 50s. Highs in the mid 70s.

Day: Partly sunny. Highs in the upper 70s.

Night: Partly cloudy. Lows in the upper 50s.

Day: Partly sunny. Highs around 80.

Night: Partly cloudy. Lows in the upper 50s. Highs in the lower 80s.

Night: Partly cloudy this evening, then clearing. Lows in the lower 70s. South winds around 5 mph.

Day: Mostly sunny. Hot with highs in the mid 90s. West winds 5 to 10 mph.

Night: Partly cloudy in the evening, then becoming mostly cloudy. A chance of showers. A chance of thunderstorms after midnight. Lows in the upper 60s. North winds around 5 mph. Chance of rain 50 percent.

Day: Partly sunny with a chance of showers and thunderstorms. Highs in the mid 80s. Northeast winds 5 to 10 mph. Chance of rain 50 percent.

Night: Mostly cloudy. A chance of showers after midnight. Lows around 60. Northeast winds 5 to 10 mph. Chance of rain 50 percent.

Day: Partly sunny. Highs in the mid 70s.

Night: Partly cloudy. Lows in the mid 50s. Highs in the mid 70s.

Day: Partly cloudy. Lows in the mid 50s. Highs in the mid 70s.

Day: Partly cloudy. Lows in the mid 50s. Highs in the mid 70s.

Night: Mostly cloudy. Lows in the upper 50s. Highs in the upper 70s.

Night: Partly cloudy. Lows in the upper 50s. Highs in the lower 80s.

Night: Mostly clear. Near steady temperature in the mid 70s. Southwest winds around 5 mph.

Day: Mostly sunny. Highs in the mid 90s. West winds around 5 mph.

Night: Mostly cloudy with a chance of showers and thunderstorms. Lows in the upper 60s. North winds around 5 mph. Chance of rain 50 percent.

Day: Partly sunny with a chance of thunderstorms. A chance of showers in the morning, then showers likely in the afternoon. Cooler with highs in the lower 80s. North winds 5 to 10 mph. Chance of rain 40 percent.

Night: Mostly cloudy with a slight chance of thunderstorms. A slight chance of showers in the evening, then a chance of showers after midnight. Lows around 60. North winds 5 to 10 mph. Chance of rain 50 percent.

Night: Mostly cloudy. Highs in the mid 70s. Lows in the mid 50s.

Day: Partly cloudy. Highs in the mid 70s. Lows in the lower 50s.

Day: Partly cloudy. Highs in the mid 70s. Lows in the lower 50s.

Night: Mostly cloudy in the evening, then becoming partly cloudy. Lows in the mid 50s.

Day: Partly sunny with a 20 percent chance of showers. Highs in the upper 70s.

Night: Partly cloudy. Lows in the mid 50s. Highs in the lower 80s.

Night: Partly cloudy. Lows in the lower 70s. Southwest winds around 5 mph.

Day: Mostly sunny. Highs in the lower 90s. West winds around 5 mph. Heat index values up to 100.

Night: Mostly cloudy with a chance of showers and thunderstorms. Lows in the upper 60s. North winds around 5 mph. Chance of rain 50 percent.

Day: Mostly cloudy in the morning, then becoming partly sunny. A chance of thunderstorms. A chance of showers in the morning, then showers likely in the afternoon. Cooler with highs around 80. North winds around 5 mph. Chance of rain 40 percent.

Night: Mostly cloudy. A chance of showers with a slight chance of thunderstorms in the evening, then a slight chance of showers after midnight. Lows in the upper 50s. North winds 5 to 10 mph. Chance of rain 40 percent.

Night: Mostly cloudy. Highs in the lower 70s. Lows in the mid 50s.

Day: Partly cloudy. Highs in the mid 70s. Lows in the lower 50s.

Day: Partly cloudy. Highs in the mid 70s. Lows in the lower 50s.

Night: Mostly cloudy. Lows in the mid 50s.

Day: Partly sunny with a 20 percent chance of showers. Highs in the upper 70s.

Night: Partly cloudy. Lows in the upper 50s. Highs in the lower 80s.

Night: Mostly clear. Lows in the lower 70s. South winds around 5 mph.

Day: Mostly sunny. Hot with highs in the upper 90s. West winds 5 to 10 mph.

Night: Partly cloudy in the evening, then mostly cloudy with a chance of showers and thunderstorms after midnight. Lows in the upper 60s. North winds around 5 mph. Chance of rain 50 percent.

Day: Mostly cloudy in the morning, then becoming partly sunny. A chance of showers and thunderstorms. Highs in the upper 80s. Northeast winds 5 to 10 mph. Chance of rain 50 percent.

Night: Mostly cloudy. A chance of showers after midnight. Lows in the lower 60s. Northeast winds 5 to 10 mph. Chance of rain 50 percent.

Day: Partly sunny. Highs in the upper 70s.

Night: Partly cloudy. Lows in the upper 50s. Highs in the upper 70s.

Day: Partly cloudy. Lows in the upper 50s. Highs in the upper 70s.

Night: Partly cloudy. Lows in the upper 50s. Highs in the upper 70s.

Day: Partly sunny. Highs in the upper 70s.

Night: Partly cloudy. Lows in the upper 50s. Highs in the lower 80s.

Night: Mostly clear. Lows in the lower 70s. Southwest winds around 5 mph.

Day: Mostly sunny. Hot with highs in the mid 90s. West winds around 5 mph.

Night: Partly cloudy in the evening, then mostly cloudy with a chance of showers and thunderstorms after midnight. Lows in the upper 60s. North winds around 5 mph. Chance of rain 50 percent.

Day: Partly sunny with a chance of thunderstorms. A chance of showers in the morning, then showers likely in the afternoon. Highs in the mid 80s. North winds 5 to 10 mph. Chance of rain 60 percent.

Night: Mostly cloudy. A chance of showers after midnight. Lows in the lower 60s. Northeast winds 5 to 10 mph. Chance of rain 50 percent.

Day: Partly sunny. Highs in the mid 70s.

Night: Partly cloudy. Lows in the mid 50s. Highs in the mid 70s.

Day: Partly cloudy. Lows in the mid 50s. Highs in the mid 70s.

Night: Partly cloudy. Lows in the mid 50s. Highs in the mid 70s.

Day: Partly sunny. Highs in the upper 70s.

Night: Partly cloudy. Lows in the upper 50s. Highs in the lower 80s.

Night: Partly cloudy. Near steady temperature in the lower 70s. Southwest winds around 5 mph.

Day: Partly sunny with a slight chance of showers. A slight chance of thunderstorms in the afternoon. Highs in the upper 80s. Northwest winds 5 to 10 mph. Chance of rain 20 percent.

Night: Showers likely with a chance of thunderstorms. Lows in the lower 60s. Northeast winds 5 to 10 mph. Chance of rain 70 percent.

Day: Mostly cloudy with a chance of showers. A slight chance of thunderstorms in the afternoon. Cooler with highs in the mid 70s. Northeast winds 5 to 10 mph. Chance of rain 50 percent.

Night: Mostly cloudy with a 50 percent chance of showers. Lows in the mid 50s. Northeast winds 5 to 10 mph.

Night: Mostly cloudy. Highs in the upper 60s. Lows in the lower 50s.

Night: Partly cloudy. Highs in the lower 70s. Lows in the lower 50s.

Day: Partly sunny. Highs in the mid 70s.

Night: Mostly cloudy. A 20 percent chance of showers. Lows in the mid 50s. Highs in the upper 70s.

Night: Partly cloudy. Lows in the mid 50s. Highs around 80.

Night: Partly cloudy. Near steady temperature in the mid 70s. Southwest winds around 5 mph.

Day: Partly sunny. Highs in the lower 90s. West winds 5 to 10 mph.

Night: Showers likely with a chance of thunderstorms. Lows in the upper 60s. North winds 5 to 10 mph. Chance of rain 70 percent.

Day: Mostly cloudy with a chance of showers with a slight chance of thunderstorms. Cooler with highs in the upper 70s. Northeast winds 5 to 10 mph. Chance of rain 50 percent.

Night: Mostly cloudy. A chance of showers with a slight chance of thunderstorms in the evening, then a slight chance of showers after midnight. Lows around 60. Northeast winds 5 to 10 mph. Chance of rain 50 percent.

Night: Mostly cloudy. Highs in the lower 70s. Lows in the mid 50s.

Night: Partly cloudy. Highs in the lower 70s. Lows in the mid 50s.

Day: Partly sunny. Highs in the mid 70s.

Night: Mostly cloudy. A 20 percent chance of showers. Lows in the upper 50s. Highs in the upper 70s.

Night: Partly cloudy. Lows in the upper 50s. Highs in the lower 80s.

Night: Partly cloudy this evening, then clearing. Lows in the lower 70s. South winds around 5 mph.

Day: Mostly sunny. Hot with highs in the mid 90s. West winds around 5 mph.

Night: Partly cloudy in the evening, then mostly cloudy with a chance of showers and thunderstorms after midnight. Lows in the mid 60s. North winds around 5 mph. Chance of rain 50 percent.

Day: A chance of thunderstorms in the morning. Mostly cloudy with a chance of showers. Highs in the mid 80s. Northeast winds 5 to 10 mph. Chance of rain 50 percent.

Night: Mostly cloudy with a chance of showers. Lows in the upper 50s. Northeast winds 5 to 10 mph. Chance of rain 50 percent.

Day: Mostly cloudy with a chance of showers in the morning, then partly sunny in the afternoon. Highs in the mid 70s. Chance of rain 50 percent.

Night: Mostly cloudy in the evening, then becoming partly cloudy. Lows in the mid 50s.

Night: Partly cloudy. Highs in the mid 70s. Lows in the mid 50s.

Day: Partly sunny. Highs in the upper 70s.

Night: Partly cloudy. Lows in the upper 50s.

Day: Partly sunny. Highs in the upper 70s.

Night: Partly cloudy. Lows in the mid 50s. Highs in the lower 80s.

Night: Partly cloudy. Lows in the lower 70s. South winds around 5 mph.

Day: Mostly sunny. Highs in the lower 90s. West winds 5 to 10 mph.

Night: Mostly cloudy with a chance of thunderstorms. A slight chance of showers in the evening, then showers likely after midnight. Lows in the mid 60s. North winds 5 to 10 mph. Chance of rain 60 percent.

Day: Mostly cloudy. Showers likely with a chance of thunderstorms in the morning, then a chance of showers in the afternoon. Not as warm with highs in the lower 80s. Northeast winds 5 to 10 mph. Chance of rain 60 percent.

Night: Mostly cloudy with a chance of showers. Lows in the upper 50s. Northeast winds 5 to 10 mph. Chance of rain 50 percent.

Night: Mostly cloudy. Highs in the lower 70s. Lows in the mid 50s.

Night: Partly cloudy. Highs in the mid 70s. Lows in the mid 50s.

Day: Mostly cloudy. Highs in the upper 70s. Lows in the upper 50s.

Day: Mostly cloudy. Highs in the upper 70s. Lows in the upper 50s.

Night: Partly cloudy. Lows in the mid 50s. Highs around 80.

Night: Partly cloudy this evening, then becoming mostly clear. Lows in the lower 70s. South winds around 5 mph.

Day: Mostly sunny. Hot with highs in the upper 90s. West winds 5 to 10 mph.

Night: Partly cloudy in the evening, then mostly cloudy with a chance of showers and thunderstorms after midnight. Lows in the upper 60s. North winds around 5 mph. Chance of rain 50 percent.

Day: Partly sunny with a chance of showers. Highs in the upper 80s. Northeast winds 5 to 10 mph. Chance of rain 50 percent.

Night: Mostly cloudy. A chance of showers after midnight. Lows in the lower 60s. Northeast winds 5 to 10 mph. Chance of rain 50 percent.

Day: Mostly cloudy with a chance of showers in the morning, then partly sunny in the afternoon. Highs in the upper 70s. Chance of rain 50 percent.

Night: Partly cloudy. Lows in the upper 50s. Highs in the mid 70s.

Night: Partly cloudy. Lows in the upper 50s. Highs in the mid 70s.

Day: Partly sunny. Highs in the upper 70s.

Night: Partly cloudy. Lows in the upper 50s.

Day: Partly sunny. Highs in the upper 70s.

Night: Partly cloudy. Lows in the upper 50s. Highs in the lower 80s.

Night: Mostly clear. Near steady temperature in the mid 70s. Southwest winds around 5 mph.

Day: Mostly sunny. Highs in the mid 90s. West winds around 5 mph.

Night: Mostly cloudy with a chance of showers and thunderstorms. Lows in the upper 60s. North winds around 5 mph. Chance of rain 50 percent.

Day: Partly sunny with a chance of thunderstorms. A chance of showers in the morning, then showers likely in the afternoon. Cooler with highs in the lower 80s. North winds 5 to 10 mph. Chance of rain 40 percent.

Night: Mostly cloudy with a slight chance of thunderstorms. A slight chance of showers in the evening, then a chance of showers after midnight. Lows around 60. North winds 5 to 10 mph. Chance of rain 50 percent.

Night: Mostly cloudy. Highs in the mid 70s. Lows in the mid 50s.

Day: Partly cloudy. Highs in the mid 70s. Lows in the lower 50s.

Day: Partly cloudy. Highs in the mid 70s. Lows in the lower 50s.

Night: Mostly cloudy in the evening, then becoming partly cloudy. Lows in the mid 50s.

Day: Partly sunny with a 20 percent chance of showers. Highs in the upper 70s.

Night: Partly cloudy. Lows in the mid 50s. Highs in the lower 80s.

Night: Mostly clear. Lows in the lower 70s. Southwest winds around 5 mph.

Day: Mostly sunny. Hot with highs in the upper 90s. West winds 5 to 10 mph.

Night: Partly cloudy. A chance of showers and thunderstorms after midnight. Lows in the upper 60s. North winds around 5 mph. Chance of rain 40 percent.

Day: Partly sunny with a chance of showers. A chance of thunderstorms in the afternoon. Highs in the upper 80s. Northeast winds 5 to 10 mph. Chance of rain 50 percent.

Night: Mostly cloudy. A chance of showers after midnight. Lows in the lower 60s. Northeast winds 5 to 10 mph. Chance of rain 50 percent.

Day: Partly sunny. Highs in the upper 70s.

Night: Partly cloudy. Lows in the upper 50s. Highs in the upper 70s.

Day: Partly cloudy. Lows in the upper 50s. Highs in the upper 70s.

Night: Partly cloudy. Lows in the upper 50s. Highs in the upper 70s.

Day: Partly sunny. Highs in the upper 70s.

Night: Partly cloudy. Lows in the upper 50s. Highs in the lower 80s.

Night: Partly cloudy. Lows in the lower 70s. Southwest winds around 5 mph.

Day: Mostly sunny. Highs in the lower 90s. West winds around 5 mph. Heat index values up to 100.

Night: Mostly cloudy with a chance of showers and thunderstorms. Lows in the upper 60s. North winds around 5 mph. Chance of rain 50 percent.

Day: Mostly cloudy in the morning, then becoming partly sunny. A chance of thunderstorms. A chance of showers in the morning, then showers likely in the afternoon. Cooler with highs around 80. North winds around 5 mph. Chance of rain 40 percent.

Night: Mostly cloudy. A chance of showers with a slight chance of thunderstorms in the evening, then a slight chance of showers after midnight. Lows in the upper 50s. North winds 5 to 10 mph. Chance of rain 40 percent.

Night: Mostly cloudy. Highs in the lower 70s. Lows in the mid 50s.

Day: Partly cloudy. Highs in the mid 70s. Lows in the lower 50s.

Day: Partly cloudy. Highs in the mid 70s. Lows in the lower 50s.

Night: Mostly cloudy. Lows in the mid 50s.

Day: Partly sunny with a 20 percent chance of showers. Highs in the upper 70s.

Night: Partly cloudy. Lows in the upper 50s. Highs in the lower 80s.

Night: Partly cloudy. Lows in the lower 70s. South winds around 5 mph.

Day: Partly sunny. A slight chance of showers and thunderstorms in the afternoon. Highs in the lower 90s. West winds 5 to 10 mph. Chance of rain 20 percent.

Night: Mostly cloudy with a chance of showers and thunderstorms. Lows in the mid 60s. Northeast winds 5 to 10 mph. Chance of rain 50 percent.

Day: Mostly cloudy with a chance of showers. Cooler with highs in the upper 70s. Northeast winds 5 to 10 mph. Chance of rain 50 percent.

Night: Mostly cloudy with a 40 percent chance of showers. Lows in the upper 50s. Northeast winds 5 to 10 mph.

Night: Mostly cloudy. Highs in the lower 70s. Lows in the mid 50s.

Night: Partly cloudy. Highs in the lower 70s. Lows in the mid 50s.

Day: Mostly cloudy. Highs in the mid 70s. Lows in the mid 50s.

Day: Mostly cloudy. Highs in the mid 70s. Lows in the mid 50s.

Night: Partly cloudy. Lows in the mid 50s. Highs in the upper 70s.

Night: Mostly clear. Lows in the lower 70s. Southwest winds around 5 mph.

Day: Mostly sunny. Hot with highs in the mid 90s. West winds around 5 mph.

Night: Partly cloudy in the evening, then mostly cloudy with a chance of showers and thunderstorms after midnight. Lows in the upper 60s. North winds around 5 mph. Chance of rain 40 percent.

Day: Partly sunny with a chance of thunderstorms. A chance of showers in the morning, then showers likely in the afternoon. Highs in the mid 80s. North winds around 5 mph. Chance of rain 70 percent.

Night: Mostly cloudy. A chance of showers after midnight. Lows in the lower 60s. North winds 5 to 10 mph. Chance of rain 50 percent.

Day: Partly sunny. Highs in the mid 70s.

Night: Partly cloudy. Lows in the mid 50s. Highs in the mid 70s.

Day: Partly cloudy. Lows in the mid 50s. Highs in the mid 70s.

Night: Partly cloudy. Lows in the mid 50s. Highs in the mid 70s.

Day: Partly sunny. Highs in the upper 70s.

Night: Partly cloudy. Lows in the upper 50s. Highs in the lower 80s.