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Keystone Weather Forecast
| TODAY | TONIGHT | SATURDAY | SATURDAY NIGHT | SUNDAY | SUNDAY NIGHT | LABOR DAY | MONDAY NIGHT | TUESDAY | TUESDAY NIGHT | WEDNESDAY | WEDNESDAY NIGHT |
 |  |  |  | |  | | |  | | | |
| Mostly Sunny | Chance of T-Storm | Chance of T-Storm | Clearing | Mostly Sunny | Mostly Clear | Mostly Sunny | Partly Cloudy | Partly Cloudy | Partly Cloudy | Partly Cloudy | Chance of T-Storm |
| Hi: 90°FHi: 32°C | Lo: 71°FLo: 22°C | Hi: 85°FHi: 29°C | Lo: 61°FLo: 16°C | Hi: 80°FHi: 27°C | Lo: 59°FLo: 15°C | Hi: 81°FHi: 27°C | Lo: 61°FLo: 16°C | Hi: 85°FHi: 29°C | Lo: 69°FLo: 21°C | Hi: 89°FHi: 32°C | Lo: 70°FLo: 21°C |
| POP: 40% | POP: 30% | POP: 40% |
POP = Probability of Precipitation.
Weather Outlook Updated: 558 AM EDT Fri Sep 04 2026 
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Issued: 535 AM EDT Fri Sep 4 2026
Key Messages
- Heat and humidity continue with peak heat indices around 100 degrees.
- 20-40% chance of thunderstorms today and tonight. Widespread severe weather is not expected, but damaging wind gusts and hail cannot be ruled out.
- A dry pattern takes over Sunday through Tuesday.
Discussion
... Issued at 238 AM EDT Fri Sep 4 2026
Another murky forecast period lies ahead with respect to thunderstorms today. First, the heat advisory was expanded once again to encompass remaining northern Indiana countie...