| NWS Forecast for: Grundy County Issued by: National Weather Service Chicago, IL Last Update: 256 PM CDT Sat Aug 29 2026 |  |
Late This Afternoon: Mostly cloudy. Temperatures in the upper 70s. South winds around 10 mph. Tonight: Mostly cloudy. Lows in the upper 60s. South winds 5 to 10 mph. Sunday: Mostly cloudy. A slight chance of thunderstorms with isolated showers in the morning. A slight chance of thunderstorms with isolated showers late. Humid with highs in the upper 80s. South winds 10 to 15 mph. Gusts up to 25 mph in the afternoon. Chance of precipitation 20 percent. Sunday Night: Mostly cloudy. Lows around 70. South winds around 10 mph. Monday: Mostly cloudy in the morning, then becoming partly cloudy. Hot with highs in the lower 90s. South winds 5 to 10 mph. Heat index values up to 100 in the afternoon. Monday Night: Partly cloudy. Lows in the mid 70s. Southwest winds 5 to 10 mph. Tuesday: Partly cloudy. Hot with highs in the mid 90s. Tuesday Night: Partly cloudy in the evening, then becoming mostly clear. Lows in the mid 70s. Wednesday: Mostly sunny. Hot with highs in the mid 90s. Wednesday Night: Mostly clear in the evening, then becoming partly cloudy. Lows in the lower 70s. Thursday: Mostly sunny in the morning, then becoming partly cloudy. Highs in the lower 90s. Thursday Night: Partly cloudy. Lows around 70. Friday: Partly cloudy. Highs in the upper 80s. Friday Night: Partly cloudy. Lows in the upper 60s. Saturday: Partly cloudy. Highs in the upper 80s. | |
| Zone Forecast: Grundy County | |
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