Keystone, PA Weather Forecast
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Keystone Weather Forecast
| OVERNIGHT | SUNDAY | SUNDAY NIGHT | MONDAY | MONDAY NIGHT | TUESDAY | TUESDAY NIGHT | WEDNESDAY | WEDNESDAY NIGHT | THURSDAY | THURSDAY NIGHT | FRIDAY |
| Showers | Showers | Chance of Showers | Mostly Cloudy | Chance of Showers | Chance of Showers | Chance of Showers | Chance of Showers | Chance of Showers | Chance of Showers | Partly Cloudy | Partly Sunny |
| Lo: 59°FLo: 15°C | Hi: 69°FHi: 21°C | Lo: 51°FLo: 11°C | Hi: 69°FHi: 21°C | Lo: 45°FLo: 7°C | Hi: 61°FHi: 16°C | Lo: 45°FLo: 7°C | Hi: 61°FHi: 16°C | Lo: 45°FLo: 7°C | Hi: 61°FHi: 16°C | Lo: 45°FLo: 7°C | Hi: 65°FHi: 18°C |
| POP: 100% | POP: 100% | POP: 50% | POP: 50% | POP: 50% | POP: 40% | POP: 40% | POP: 30% | POP: 30% |
POP = Probability of Precipitation.
Weather Outlook Updated: 230 AM EDT Sun Sep 20 2026 

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Issued: 227 AM EDT Sun Sep 20 2026
Key Messages
1) A low pressure system will bring a period of steady rain and showers to the area today. Rainfall amounts between a half inch to one inch are expected.
2) The weather pattern is trending drier, with cooler, fall temperatures for much of next week. A stalled front and later a stronger low off the East Coast could keep shower chances nearby.
Discussion
... KEY MESSAGE 1...
Low pressure is now forecast to track a little further south across southern PA today, so this will keep the bulk of...
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