| NWS Forecast for: Union County Issued by: National Weather Service Sioux Falls, SD Last Update: 838 AM CDT Sat Jul 25 2026 |  |
Rest Of Today: Patchy fog early this morning. Mostly sunny. Much warmer with highs in the upper 90s. Southwest winds 5 to 10 mph. Heat index values up to 110 this afternoon. Tonight: Mostly cloudy with a slight chance of thunderstorms. A chance of showers, mainly in the evening. Humid with lows in the mid 70s. South winds 5 to 10 mph, becoming east with gusts up to 20 mph after midnight. Chance of rain 30 percent. Heat index values up to 110 early in the evening. Sunday: Mostly cloudy with a slight chance of showers and thunderstorms in the morning, then mostly sunny in the afternoon. Hot with highs in the upper 90s. South winds 5 to 10 mph with gusts up to 20 mph, increasing to 15 to 20 mph with gusts up to 30 mph in the afternoon. Chance of rain 20 percent. Heat index values up to 108. Sunday Night: Partly cloudy with a chance of showers and thunderstorms in the evening, then mostly clear with a chance of sprinkles after midnight. Humid with lows in the mid 70s. South winds 15 to 20 mph with gusts up to 30 mph, becoming southwest 5 to 10 mph with gusts up to 20 mph after midnight. Chance of rain 30 percent. Heat index values up to 105 early in the evening. Monday: Sunny, hot with highs in the mid 90s. North winds 5 to 10 mph. Monday Night: Mostly clear in the evening, then becoming mostly cloudy. Lows in the lower 70s. Heat index values in the upper 90s early in the evening. Tuesday: Mostly sunny. Highs in the lower 90s. Tuesday Night: Mostly clear. Lows in the upper 60s. Wednesday: Mostly sunny. Highs in the lower 90s. Wednesday Night: Partly cloudy. A chance of showers and thunderstorms after midnight. Lows in the upper 60s. Chance of rain 40 percent. Thursday: Partly sunny. A chance of showers and thunderstorms in the morning. Highs in the lower 90s. Chance of rain 40 percent. Thursday Night: Mostly clear with a chance of showers. A chance of thunderstorms after midnight. Lows in the upper 60s. Chance of rain 40 percent. Friday: Mostly sunny. Highs around 90. | |
| Zone Forecast: Union County | |
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