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Post Lake, SD Weather Forecast
Post Lake, SD Weather Forecast Date: 1207 AM CDT Sat Aug 22 2026
The area/counties/county of: Sully, including the city of Onida.or toggle through each period.
Rest of Tonight... Partly cloudy. Lows around 60. Northeast winds 5 to 10 mph.
Saturday... Mostly sunny. Highs in the lower 80s. Northeast winds 5 to 10 mph.
Saturday Night... Partly cloudy in the evening, then mostly cloudy with a chance of showers with a slight chance of thunderstorms after midnight. Lows around 60. East winds 10 to 15 mph with gusts up to 25 mph. Chance of rain 50%.
Sunday... Mostly cloudy with a chance of showers with a slight chance of thunderstorms in the morning, then partly sunny with a chance of thunderstorms in the afternoon. Highs in the lower 80s. Southeast winds 15 to 20 mph with gusts up to 30 mph. Chance of rain 50%.
Sunday Night... Showers likely with a chance of thunderstorms in the evening, then a chance of showers with a slight chance of thunderstorms after midnight. Humid with lows in the lower 60s. Southeast winds 15 to 20 mph with gusts up to 30 mph. Chance of rain 70%.
Monday... Partly sunny. Highs in the upper 80s.
Monday Night... Partly cloudy. A slight chance of thunderstorms in the evening. Lows in the lower 60s. Chance of rain 20%.
Tuesday... Partly sunny. Highs in the mid 80s.
Tuesday Night... Mostly clear. Lows in the upper 50s. Highs in the mid 80s.
Wednesday... Mostly clear. Lows in the upper 50s. Highs in the mid 80s.
Thursday... Partly sunny. A slight chance of thunderstorms in the afternoon. Highs in the mid 80s. Chance of rain 20%.
Thursday Night... Partly cloudy. A chance of thunderstorms, mainly in the evening. Lows in the upper 50s. Chance of rain 30%.
POP = Probability of Precipitation
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