As of 4:02 PM CDT on August 17, 2026, all 98 cities in St. Louis County, MO in our database have a UV Index reading of Moderate. The city with the highest UV Index reading right now is Oakville, MO with a reading of 4.1.
Over the next 24 hours, the highest UV Index reading in St. Louis County, MO is expected to be 9.1 in Oakville between 1:00 PM - 2:00 PM CDT tomorrow.
| Range | 0 - 2 | 3 - 5 | 6 - 7 | 8 - 10 | 11+ |
|---|---|---|---|---|---|
| Color | |||||
| Risk | Low | Moderate | High | Very High | Extreme |