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City of Mt. Vernon, MOMount Vernon, MO Weather Forecast
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Mount Vernon Weather Forecast
| THIS AFTERNOON | TONIGHT | SATURDAY | SATURDAY NIGHT | SUNDAY | SUNDAY NIGHT | MONDAY | MONDAY NIGHT | TUESDAY | TUESDAY NIGHT | WEDNESDAY | WEDNESDAY NIGHT |
 |  | |  |  |  | |  |  |  | | |
| Sunny | Mostly Clear | Sunny | Mostly Cloudy | Chance of T-Storm | Chance of T-Storm | Chance of T-Storm | Chance of Showers | Partly Sunny | Partly Cloudy | Mostly Clear | Mostly Clear |
| Hi: 95°FHi: 35°C | Lo: 71°FLo: 22°C | Hi: 99°FHi: 37°C | Lo: 71°FLo: 22°C | Hi: 95°FHi: 35°C | Lo: 65°FLo: 18°C | Hi: 81°FHi: 27°C | Lo: 60°FLo: 16°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: 55°FLo: 13°C |
| POP: 40% | POP: 70% | POP: 50% | POP: 20% |
POP = Probability of Precipitation.
Weather Outlook Updated: 127 PM CDT Fri Sep 18 2026 
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Issued: 110 PM CDT Fri Sep 18 2026
Key Messages
- A Heat Advisory is in effect through Saturday. Highs near 100 with Heat Index values 100-105 can be expected. Daily records may continue to be tied or broken.
- Less than 20% chance for isolated showers and storms this afternoon, particularly across the eastern Ozarks and south- central Missouri.
- Cooler conditions with scattered rain chances arrive early next week. Details on the exact extent of the cooldown and location of the highest rain chances remain uncertain at this time.