As of 3:01 PM CDT on September 20, 2026, all 4 cities in Mercer County, MO in our database have a UV Index reading of Low. The city with the highest UV Index reading right now is Princeton, MO with a reading of 1.8.
Over the next 24 hours, the highest UV Index reading in Mercer County, MO is expected to be 1.8 in Princeton between 3:00 PM - 4:00 PM CDT today.
| Range | 0 - 2 | 3 - 5 | 6 - 7 | 8 - 10 | 11+ |
|---|---|---|---|---|---|
| Color | |||||
| Risk | Low | Moderate | High | Very High | Extreme |