As of 8:29 PM CDT on August 17, 2026, all 12 cities in Johnson County, IA 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 Johnson County, IA is expected to be 6.4 in Frytown between 2:00 PM - 3:00 PM CDT tomorrow.
| Range | 0 - 2 | 3 - 5 | 6 - 7 | 8 - 10 | 11+ |
|---|---|---|---|---|---|
| Color | |||||
| Risk | Low | Moderate | High | Very High | Extreme |