Weather WorldGranite City, IL Weather Forecast
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Granite City Weather Forecast
| TONIGHT | MONDAY | MONDAY NIGHT | TUESDAY | TUESDAY NIGHT | WEDNESDAY | WEDNESDAY NIGHT | THURSDAY | THURSDAY NIGHT | FRIDAY | FRIDAY NIGHT | SATURDAY |
 |  |  | |  |  |  |  |  | | | |
| Mostly Cloudy | Sunny | Mostly Clear | Sunny | Partly Cloudy | Partly Sunny | Chance of Showers | Chance of T-Storm | Chance of T-Storm | Chance of T-Storm | Chance of T-Storm | Chance of T-Storm |
| Lo: 55°FLo: 13°C | Hi: 79°FHi: 26°C | Lo: 55°FLo: 13°C | Hi: 81°FHi: 27°C | Lo: 65°FLo: 18°C | Hi: 89°FHi: 32°C | Lo: 70°FLo: 21°C | Hi: 81°FHi: 27°C Lo: 61°FLo: 16°C | Hi: 81°FHi: 27°C Lo: 61°FLo: 16°C | Hi: 70°FHi: 21°C | Hi: 69°FHi: 21°C Lo: 55°FLo: 13°C | Hi: 69°FHi: 21°C Lo: 55°FLo: 13°C |
| POP: 20% | POP: 70% | POP: 70% | POP: 50% | POP: 20% | POP: 20% |
POP = Probability of Precipitation.
Weather Outlook Updated: 258 PM CDT Sun Sep 27 2026 
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Issued: 243 PM CDT Sun Sep 27 2026
Key Messages
- Rainfall arrives for some by Wednesday, becoming more widespread Thursday into Friday. Northeast/central MO and west-central IL have the best chance (30%) of receiving substantial rainfall (2").
- Gradual warming continues, with high temperatures in the 80s for most locations Tuesday and Wednesday.
Aviation
/18Z TAFS THROUGH 00Z TUESDAY/... Issued at 1230 PM CDT Sun Sep 27 2026
Isolated to scattered light showers continue to slide southeastward across portions of central/northeast MO and ...