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Jefferson County Weather Forecast
| TONIGHT | SATURDAY | SATURDAY NIGHT | SUNDAY | SUNDAY NIGHT | MONDAY | MONDAY NIGHT | TUESDAY | TUESDAY NIGHT | WEDNESDAY | THURSDAY | FRIDAY |
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| Mostly Cloudy | Mostly Cloudy | Chance of Showers | Partly Sunny | Partly Cloudy | Partly Cloudy | Partly Cloudy | Chance of Showers | Chance of Showers | Chance of T-Storm | Chance of T-Storm | Chance of T-Storm |
| Lo: 59°FLo: 15°C | Hi: 71°FHi: 22°C | Lo: 59°FLo: 15°C | Hi: 75°FHi: 24°C | Lo: 59°FLo: 15°C | Hi: 79°FHi: 26°C Lo: 55°FLo: 13°C | Hi: 79°FHi: 26°C Lo: 55°FLo: 13°C | Hi: 79°FHi: 26°C | Lo: 65°FLo: 18°C | Hi: 79°FHi: 26°C Lo: 65°FLo: 18°C | Hi: 79°FHi: 26°C Lo: 65°FLo: 18°C | Hi: 79°FHi: 26°C |
| POP: 20% | POP: 20% | POP: 30% | POP: 50% | POP: 50% | POP: 40% |
POP = Probability of Precipitation.
Weather Outlook Updated: 833 PM CDT Fri Sep 25 2026 
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Instant definitions for any meteorological term.
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Issued: 610 PM CDT Fri Sep 25 2026
Key Messages
- Seasonably cool and cloudy weather is expected to continue into the weekend, with the coolest conditions for those who see rain.
- The best rain chances (60-80%) are across northeast MO/west- central IL this weekend. More widespread and significant (0.50+ inches) rainfall is expected next week.
Aviation
/00Z TAFS THROUGH 06Z SUNDAY/... Issued at 606 PM CDT Fri Sep 25 2026
VFR conditions are expected to prevail through the 06Z TAF period, with only a few low-probability exceptions. At St. ...