Williamson, IL Weather Forecast
Quick Weather Clicks
Settings
Sun & Moon
Williamson Weather Forecast
| THIS AFTERNOON | TONIGHT | FRIDAY | FRIDAY NIGHT | SATURDAY | SATURDAY NIGHT | SUNDAY | SUNDAY NIGHT | MONDAY | MONDAY NIGHT | TUESDAY | TUESDAY NIGHT |
| Chance of T-Storm | Patchy Fog | Chance of Showers | Partly Cloudy | Mostly Sunny | Partly Cloudy | Chance of T-Storm | Partly Cloudy | Mostly Clear | Mostly Clear | Chance of T-Storm | Chance of T-Storm |
| Hi: 79°FHi: 26°C | Lo: 69°FLo: 21°C | Hi: 81°FHi: 27°C | Lo: 69°FLo: 21°C | Hi: 90°FHi: 32°C | Lo: 69°FLo: 21°C | Hi: 89°FHi: 32°C | Lo: 69°FLo: 21°C | Hi: 91°FHi: 33°C Lo: 70°FLo: 21°C | Hi: 91°FHi: 33°C Lo: 70°FLo: 21°C | Hi: 91°FHi: 33°C | Lo: 69°FLo: 21°C |
| POP: 20% | POP: 20% | POP: 20% | POP: 30% | POP: 40% |
POP = Probability of Precipitation.
Weather Outlook Updated: 127 PM CDT Thu Sep 10 2026 

Williamson Radar Loop
Use the map search tool if you want to place a location marker on the radar map...
Williamson Weather Map
Williamson Quick Facts
Williamson Forecast Discussion
Meteorlogic Glosserator
Instant definitions for any meteorological term.
Instant definitions for any meteorological term.
Issued: 218 PM CDT Thu Sep 10 2026
Key Messages
- Slowly increasing temperatures are expected tomorrow through early next week, reaching seasonable, but slightly above average values.
- Occasional chances (20-30%) for showers exist this weekend through early next week, but largely dry conditions are expected until Tuesday onward.
&
.SHORT TERM /THROUGH FRIDAY/... Issued at 214 PM CDT Thu Sep 10 2026
While widespread rain has largely ended across the region, the main focus of the next couple of days will be the lingering potential for a f...
Weather World