As of 4:07 PM EST on December 15, 2025, all 11 cities in Johnston County, NC in our database have a UV Index reading of Low. The city with the highest UV Index reading right now is Clayton, NC with a reading of 0.3.
Over the next 24 hours, the highest UV Index reading in Johnston County, NC is expected to be 2.6 in Smithfield between 12:00 PM - 1:00 PM EST tomorrow.
| Range | 0 - 2 | 3 - 5 | 6 - 7 | 8 - 10 | 11+ |
|---|---|---|---|---|---|
| Color | |||||
| Risk | Low | Moderate | High | Very High | Extreme |