As of 1:50 PM MDT on September 17, 2025, all 4 cities in Costilla County, CO in our database have a UV Index reading of Very High. The city with the highest UV Index reading right now is San Luis, CO with a reading of 8.3.
Over the next 24 hours, the highest UV Index reading in Costilla County, CO is expected to be 8.3 in San Luis between 1:00 PM - 2:00 PM MDT today.
| Range | 0 - 2 | 3 - 5 | 6 - 7 | 8 - 10 | 11+ |
|---|---|---|---|---|---|
| Color | |||||
| Risk | Low | Moderate | High | Very High | Extreme |