As of 11:59 PM CDT on May 16, 2025, all 11 cities in Grundy County, IL in our database have a UV Index reading of 0, indicating no radiation from the sun.
Over the next 24 hours, the highest UV Index reading in Grundy County, IL is expected to be 4.2 in Morris between 2:00 PM - 3:00 PM CDT tomorrow.
| Range | 0 - 2 | 3 - 5 | 6 - 7 | 8 - 10 | 11+ |
|---|---|---|---|---|---|
| Color | |||||
| Risk | Low | Moderate | High | Very High | Extreme |