Weather WorldGrassy Trail Reservoir, UT Weather Forecast
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Grassy Trail Reservoir Weather Forecast
| TODAY | TONIGHT | FRIDAY | FRIDAY NIGHT | SATURDAY | SATURDAY NIGHT | SUNDAY | SUNDAY NIGHT | MONDAY | MONDAY NIGHT | TUESDAY | WEDNESDAY |
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| Chance of T-Storm | Chance of T-Storm | Chance of T-Storm | Chance of T-Storm | Chance of T-Storm | Chance of T-Storm | Partly Cloudy | Mostly Cloudy | Chance of T-Storm | Partly Cloudy | Partly Cloudy | Partly Cloudy |
| Hi: 85°FHi: 29°C | Lo: 55°FLo: 13°C | Hi: 85°FHi: 29°C | Lo: 55°FLo: 13°C | Hi: 80°FHi: 27°C | Lo: 51°FLo: 11°C | Hi: 80°FHi: 27°C | Lo: 50°FLo: 10°C | Hi: 79°FHi: 26°C | Hi: 80°FHi: 27°C Lo: 50°FLo: 10°C | Hi: 80°FHi: 27°C Lo: 50°FLo: 10°C | Hi: 80°FHi: 27°C Lo: 50°FLo: 10°C |
| POP: 30% | POP: 20% | POP: 50% | POP: 30% | POP: 60% | POP: 30% | POP: 30% |
POP = Probability of Precipitation.
Weather Outlook Updated: 1243 AM MDT Thu Aug 20 2026 
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Issued: 256 AM MDT Thu Aug 20 2026
Key Messages
.KEY MESSAGES, Issued 1002 PM MDT Wed Aug 19 2026...- Building high pressure will bring a steady warming trend in temperatures through Thursday across the south and through Friday across the north.
- Monsoon moisture will move back into Utah and southwest Wyoming late in the week, persisting through at least early next week. This will bring an increased threat of showers and thunderstorms capable of producing flash flooding.
Discussion
, Issued 1002 PM MDT We...