As of 11:10 AM CDT on March 21, 2026, out of 19 cities in Marathon County, WI in our database, 10 cities (53%) have a UV Index reading of Low, while 9 cities (47%) have a UV Index reading of Moderate. The city with the highest UV Index reading right now is Colby, WI with a reading of 3.1.
Over the next 24 hours, the highest UV Index reading in Marathon County, WI is expected to be 4.9 in Wausau 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 |