As of 5:57 PM CDT on June 30, 2026, all 19 cities in Marathon County, WI in our database have a UV Index reading of Moderate. The city with the highest UV Index reading right now is Colby, WI with a reading of 3.3.
Over the next 24 hours, the highest UV Index reading in Marathon County, WI is expected to be 9.2 in Hatley 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 |