As of 3:17 AM CDT on August 20, 2025, 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 8.5 in Iowa City between 1:00 PM - 2:00 PM CDT today.
| Range | 0 - 2 | 3 - 5 | 6 - 7 | 8 - 10 | 11+ |
|---|---|---|---|---|---|
| Color | |||||
| Risk | Low | Moderate | High | Very High | Extreme |