Weather WorldAlton Lake, IL 7-Day Weather Forecast
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Alton Lake Weather Forecast
Alton Lake, IL Weather Forecast Date: 1208 PM CDT Tue Aug 18 2026
Weather forecast for Alton Lake, IL
Today Hi: 89°FHi: 32°C Lo: 70°F Lo: 21°C |
This Afternoon... Mostly sunny. Highs in the upper 80s. Southwest winds around 5 mph. |
Wed Hi: 80°FHi: 27°C Lo: 69°F Lo: 21°C |
Wednesday... Mostly cloudy with a chance of thunderstorms. Showers, mainly in the morning. Highs around 80. Southwest winds around 5 mph. Chance of rain 90%. |
| Thu Hi: 81°FHi: 27°C Lo: 65°F Lo: 18°C |
Thursday... Mostly sunny. Highs in the lower 80s. Northeast winds around 5 mph. |
| Fri Hi: 85°FHi: 29°C Lo: 65°F Lo: 18°C |
Friday... Mostly clear. Lows in the mid 60s. Highs in the mid 80s. |
| Sat Hi: 89°FHi: 32°C Lo: 65°F Lo: 18°C |
Saturday... Mostly clear. Highs in the upper 80s. Lows in the mid 60s. |
| Sun Hi: 85°FHi: 29°C Lo: 65°F Lo: 18°C |
Sunday... Mostly sunny. Highs in the mid 80s. |
Mon Hi: 85°FHi: 29°C Lo: 65°F Lo: 18°C |
Monday... Partly cloudy. A 20% chance of showers. Lows in the mid 60s. Highs in the mid 80s. |
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