As of 11:46 AM CDT on July 18, 2025, all 18 cities in Williamson County, TX in our database have a UV Index reading of High. The city with the highest UV Index reading right now is Sonterra, TX with a reading of 7.
Over the next 24 hours, the highest UV Index reading in Williamson County, TX is expected to be 11.7 in Georgetown 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 |