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Harper, IA Weather Forecast
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Harper Weather Forecast
| TONIGHT | SATURDAY | SATURDAY NIGHT | SUNDAY | SUNDAY NIGHT | MONDAY | MONDAY NIGHT | TUESDAY | TUESDAY NIGHT | WEDNESDAY | THURSDAY | THURSDAY NIGHT |
 |  | | |  | |  |  |  |  | | |
| Chance of T-Storm | Chance of T-Storm | Chance of T-Storm | Chance of T-Storm | Chance of Showers | Chance of Showers | Chance of Showers | Mostly Cloudy | Partly Cloudy | Partly Cloudy | Partly Sunny | Partly Cloudy |
| Lo: 69°FLo: 21°C | Hi: 81°FHi: 27°C | Lo: 65°FLo: 18°C | Hi: 65°FHi: 18°C | Lo: 59°FLo: 15°C | Hi: 59°FHi: 15°C | Lo: 51°FLo: 11°C | Hi: 61°FHi: 16°C | Hi: 65°FHi: 18°C Lo: 50°FLo: 10°C | Hi: 65°FHi: 18°C Lo: 50°FLo: 10°C | Hi: 69°FHi: 21°C | Hi: 69°FHi: 21°C Lo: 55°FLo: 13°C |
| POP: 50% | POP: 70% | POP: 80% | POP: 70% | POP: 70% | POP: 60% | POP: 40% |
POP = Probability of Precipitation.
Weather Outlook Updated: 312 PM CDT Fri Sep 18 2026 
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Issued: 305 PM CDT Fri Sep 18 2026
Key Messages
- Heavy rain and thunderstorms are likely for portions of the area tonight into Saturday morning and again Saturday evening into Saturday night. Localized flash flooding is the primary concern. Rapid rises on small creeks and streams and the flooding of low-lying areas are possible.
- A Flood Watch has been issued for portions of east-central Iowa and far northwestern Illinois for late tonight through Saturday evening. Rainfall totals of 1-3 inches are likely (60-80%) in these areas with...