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City of Sycamore, ILSycamore, IL Weather Forecast
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Sycamore Weather Forecast
| REST OF TONIGHT | SUNDAY | SUNDAY NIGHT | MONDAY | MONDAY NIGHT | TUESDAY | TUESDAY NIGHT | WEDNESDAY | WEDNESDAY NIGHT | THURSDAY | THURSDAY NIGHT | FRIDAY |
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| Thunderstorms | Chance of T-Storm | Chance of Showers | Chance of Showers | Chance of Showers | Chance of Showers | Partly Cloudy | Partly Cloudy | Partly Cloudy | Partly Cloudy | Mostly Cloudy | Mostly Cloudy |
| Lo: 65°FLo: 18°C | Hi: 65°FHi: 18°C | Lo: 55°FLo: 13°C | Hi: 65°FHi: 18°C | Lo: 51°FLo: 11°C | Hi: 61°FHi: 16°C | Lo: 49°FLo: 9°C | Hi: 65°FHi: 18°C | Lo: 49°FLo: 9°C | Hi: 65°FHi: 18°C | Lo: 50°FLo: 10°C | Hi: 69°FHi: 21°C |
| POP: 100% | POP: 100% | POP: 30% | POP: 30% | POP: 30% | POP: 20% |
POP = Probability of Precipitation.
Weather Outlook Updated: 120 AM CDT Sun Sep 20 2026 
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Issued: 103 AM CDT Sun Sep 20 2026
Key Messages
- A Flood Watch for flash flooding is in effect for areas roughly along and north of the Illinois and Kankakee rivers through early Sunday morning.
- Heavy rain-producing showers and thunderstorms are expected to redevelop late tonight. Flash flooding will be possible where the heaviest rains occur over the same areas.
- Showers/drizzle and perhaps an isolated thunderstorm likely to continue for most of the area through the day on Sunday. Periods of showers to persist off-and-on through Tu...