As of 4:22 PM EDT on April 18, 2026, all 13 cities in St. Johns County, FL in our database have a UV Index reading of High. The city with the highest UV Index reading right now is St. Augustine Shores, FL with a reading of 6.2.
Over the next 24 hours, the highest UV Index reading in St. Johns County, FL is expected to be 10.3 in Flagler Estates between 1:00 PM - 2:00 PM EDT tomorrow.
| Range | 0 - 2 | 3 - 5 | 6 - 7 | 8 - 10 | 11+ |
|---|---|---|---|---|---|
| Color | |||||
| Risk | Low | Moderate | High | Very High | Extreme |