When a UV Number Alone Doesn't Tell You Enough
The UV index expresses how strongly sunlight's ultraviolet rays affect skin, on a scale from 0 up past 11. But a bare number doesn't make clear how careful you actually need to be. This converter turns a UV index into a five-level risk rating — Low, Moderate, High, Very High, and Extreme — following World Health Organization classification standards.
The recommended exposure time shown alongside it is roughly how long unprotected skin can stay in the sun before burning starts. At a "Very High" reading of 8 or above, burning can begin within 15 minutes, and at "Extreme" (11+), within 10 minutes — worth keeping in mind for summer outdoor plans.
Keep in mind these times are rough estimates for average skin, and actual results vary by individual skin type, altitude, and reflective surroundings like snow, water, or sand. Even on low-index days, sunscreen is worth using for extended outdoor time or in highly reflective environments.
Frequently Asked Questions
By WHO standards, a UV index of 8 or above is classified as "Very High" and 11 or above as "Extreme." At these levels, sunburn risk rises even with short exposure.
It's an approximate time for unprotected skin to start burning at each UV index range. Actual time varies by skin type, location, and altitude.
Even at a low index, sunscreen is recommended for long outdoor activity or in reflective environments like snow, sand, or water.