As of 1:56 PM MST on January 18, 2026, all 23 cities in Jefferson County, CO in our database have a UV Index reading of Low. The city with the highest UV Index reading right now is Coal Creek, CO with a reading of 2.2.
Over the next 24 hours, the highest UV Index reading in Jefferson County, CO is expected to be 2.2 in Coal Creek between 1:00 PM - 2:00 PM MST today.
| Range | 0 - 2 | 3 - 5 | 6 - 7 | 8 - 10 | 11+ |
|---|---|---|---|---|---|
| Color | |||||
| Risk | Low | Moderate | High | Very High | Extreme |