As of 11:42 PM CST on January 4, 2026, all 1461 cities in Illinois in our database have a UV Index reading of 0, indicating no radiation from the sun.
Over the next 24 hours, the highest UV Index reading in Illinois is expected to be 2.4 in Cairo between 12:00 PM - 1:00 PM CST tomorrow.
| Range | 0 - 2 | 3 - 5 | 6 - 7 | 8 - 10 | 11+ |
|---|---|---|---|---|---|
| Color | |||||
| Risk | Low | Moderate | High | Very High | Extreme |