As of 2:10 AM EST on December 12, 2025, all 10 cities in Mercer County, OH 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 Mercer County, OH is expected to be 1.4 in Celina between 1:00 PM - 2:00 PM EST today.
| Range | 0 - 2 | 3 - 5 | 6 - 7 | 8 - 10 | 11+ |
|---|---|---|---|---|---|
| Color | |||||
| Risk | Low | Moderate | High | Very High | Extreme |