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St. Mary's Lake, IL Weather Forecast
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St. Mary's Lake Weather Forecast
| EARLY THIS MORNING | TODAY | TONIGHT | FRIDAY | FRIDAY NIGHT | SATURDAY | SATURDAY NIGHT | SUNDAY | SUNDAY NIGHT | MONDAY | MONDAY NIGHT | TUESDAY |
 |  |  | | | | | |  |  |  | |
| Patchy Fog | Chance of T-Storm | Chance of T-Storm | Chance of T-Storm | Chance of T-Storm | Chance of T-Storm | Chance of T-Storm | Chance of T-Storm | Partly Cloudy | Partly Cloudy | Mostly Clear | Partly Cloudy |
| Hi: 65°FHi: 18°C | Hi: 79°FHi: 26°C | Lo: 69°FLo: 21°C | Hi: 79°FHi: 26°C | Lo: 69°FLo: 21°C | Hi: 81°FHi: 27°C | Lo: 70°FLo: 21°C | Hi: 81°FHi: 27°C | Lo: 65°FLo: 18°C | Hi: 75°FHi: 24°C | Lo: 60°FLo: 16°C | Hi: 79°FHi: 26°C |
| POP: 50% | POP: 50% | POP: 50% | POP: 70% | POP: 70% | POP: 70% | POP: 50% |
POP = Probability of Precipitation.
Weather Outlook Updated: 336 AM CDT Thu Aug 13 2026 
St. Mary's Lake Radar Loop
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