As of 10:44 AM CDT on October 31, 2025, all 5 cities in Clark County, IL in our database have a UV Index reading of Low. The city with the highest UV Index reading right now is Marshall, IL with a reading of 1.2.
Over the next 24 hours, the highest UV Index reading in Clark County, IL is expected to be 3.3 in Casey 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 |