As of 8:30 AM EDT on July 17, 2025, all 2 cities in Johnson County, TN in our database have a UV Index reading of Low. The city with the highest UV Index reading right now is Mountain City, TN with a reading of 0.8.
Over the next 24 hours, the highest UV Index reading in Johnson County, TN is expected to be 11 in Mountain City 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 |