As of 1:34 PM EDT on August 11, 2025, all 7 cities in Union County, OH in our database have a UV Index reading of Very High. The city with the highest UV Index reading right now is Marysville, OH with a reading of 8.5.
Over the next 24 hours, the highest UV Index reading in Union County, OH is expected to be 8.7 in Milford Center between 2:00 PM - 3:00 PM EDT today.
| Range | 0 - 2 | 3 - 5 | 6 - 7 | 8 - 10 | 11+ |
|---|---|---|---|---|---|
| Color | |||||
| Risk | Low | Moderate | High | Very High | Extreme |