As of 12:05 PM EDT on July 26, 2025, all 19 cities in Union County, NJ in our database have a UV Index reading of Very High. The city with the highest UV Index reading right now is Rahway, NJ with a reading of 8.6.
Over the next 24 hours, the highest UV Index reading in Union County, NJ is expected to be 9.1 in Plainfield 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 |