As of 3:06 AM EDT on October 30, 2025, all 17 cities in Mercer County, NJ 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, NJ is expected to be 0.7 in Trenton between 1:00 PM - 2:00 PM EDT today.
| Range | 0 - 2 | 3 - 5 | 6 - 7 | 8 - 10 | 11+ |
|---|---|---|---|---|---|
| Color | |||||
| Risk | Low | Moderate | High | Very High | Extreme |