As of 2:26 PM CDT on September 12, 2026, all 11 cities in Grundy County, IL in our database have a UV Index reading of High. The city with the highest UV Index reading right now is Morris, IL with a reading of 6.1.
Over the next 24 hours, the highest UV Index reading in Grundy County, IL is expected to be 6.1 in Morris between 2:00 PM - 3:00 PM CDT today.
| Range | 0 - 2 | 3 - 5 | 6 - 7 | 8 - 10 | 11+ |
|---|---|---|---|---|---|
| Color | |||||
| Risk | Low | Moderate | High | Very High | Extreme |