As of 5:29 PM EDT on June 11, 2026, all 10 cities in Mercer County, OH in our database have a UV Index reading of Moderate. The city with the highest UV Index reading right now is Rockford, OH with a reading of 4.5.
Over the next 24 hours, the highest UV Index reading in Mercer County, OH is expected to be 9.8 in Coldwater between 2:00 PM - 3:00 PM EDT tomorrow.
| Range | 0 - 2 | 3 - 5 | 6 - 7 | 8 - 10 | 11+ |
|---|---|---|---|---|---|
| Color | |||||
| Risk | Low | Moderate | High | Very High | Extreme |