| NWS Forecast for: Jefferson County Issued by: National Weather Service Saint Louis, MO Last Update: 333 PM CDT Fri Jul 31 2026 | |
| Tonight: Showers with a chance of thunderstorms this evening, then a chance of showers after midnight. Lows in the upper 60s. South winds 5 to 10 mph, becoming southwest after midnight. Chance of rain near 100 percent. Saturday: Mostly cloudy. A slight chance of showers in the morning, then showers likely with a slight chance of thunderstorms in the afternoon. Cooler with highs in the mid 70s. West winds around 10 mph with gusts up to 25 mph. Chance of rain 70 percent. Saturday Night: Mostly cloudy. Showers likely with a slight chance of thunderstorms in the evening, then a chance of showers after midnight. Lows in the mid 60s. Northwest winds 10 to 15 mph with gusts up to 25 mph. Chance of rain 70 percent. Sunday: Mostly cloudy in the morning, then becoming partly sunny. A 40 percent chance of showers. Highs in the upper 70s. North winds 5 to 10 mph with gusts up to 20 mph. Sunday Night: Partly cloudy. Lows in the lower 60s. North winds 5 to 10 mph. Monday: Mostly sunny. Highs in the lower 80s. Monday Night Through Wednesday Night: Mostly clear. Lows in the upper 60s. Highs in the upper 80s. Thursday And Thursday Night: Partly cloudy. A slight chance of showers and thunderstorms. Highs around 90. Lows around 70. Chance of rain 20 percent. Heat index values up to 100. Friday: Mostly sunny. Highs in the lower 90s. Heat index values up to 105. | |
| Zone Forecast: Jefferson County | |
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