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Alp Lake, MT Weather Forecast
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Alp Lake Weather Forecast
| REST OF TODAY | TONIGHT | SATURDAY | SATURDAY NIGHT | SUNDAY | SUNDAY NIGHT | MONDAY | MONDAY NIGHT | TUESDAY | TUESDAY NIGHT | WEDNESDAY | WEDNESDAY NIGHT |
 |  |  | | |  | |  | | |  |  |
| Thunderstorms | Chance of T-Storm | Chance of T-Storm | Chance of T-Storm | Chance of T-Storm | Patchy Fog | Patchy Fog | Partly Cloudy | Chance of T-Storm | Partly Cloudy | Mostly Sunny | Mostly Clear |
| Hi: 69°FHi: 21°C | Lo: 39°FLo: 4°C | Hi: 59°FHi: 15°C | Lo: 35°FLo: 2°C | Hi: 59°FHi: 15°C | Lo: 31°FLo: -1°C | Hi: 65°FHi: 18°C | Lo: 31°FLo: -1°C | Hi: 69°FHi: 21°C | Lo: 35°FLo: 2°C | Hi: 69°FHi: 21°C | Lo: 35°FLo: 2°C |
| POP: 90% | POP: 90% | POP: 80% | POP: 70% | POP: 60% | POP: 20% |
POP = Probability of Precipitation.
Weather Outlook Updated: 703 AM MDT Fri Sep 18 2026 
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Issued: 538 AM MDT Fri Sep 18 2026
Key Messages
- A few strong thunderstorms are possible, mainly around and east of Billings this afternoon and evening.
- Flood Watch tonight through Sunday for much of the area. Widespread precipitation this afternoon through the weekend, with the potential for locally heavy rainfall widespread through Saturday night.
- Chance for at least an inch of rainfall is greater than 80 percent across much of southern Montana and northern Wyoming. The chance for at least 2 inches of rainfall is 50 to 80 percent...