What the UV Index Actually Means: A Plain-English Guide
Your weather app says 'UV 8' — here's exactly what that number means for your skin and your plans.
The EPA/NWS UV Index runs from Low (0-2) through Moderate (3-5), High (6-7), Very High (8-10), to Extreme (11+); at 11+ unprotected skin can burn in minutes.
The U.S. Environmental Protection Agency designed the UV Index as a simple daily forecast so people can match their sun-protection behavior to the day's actual UV strength rather than to the temperature.
Questions we get a lot
What do the UV Index numbers mean?
The UV Index runs from Low (0-2) and Moderate (3-5) through High (6-7), Very High (8-10), and Extreme (11+). Higher numbers indicate stronger UV radiation and a faster path to skin damage. At Extreme levels, unprotected skin can burn in minutes, so protection is essential.
At what UV Index do I need sunscreen?
Protection is recommended from a UV Index of 3 (Moderate) and up, and many dermatologists advise daily sunscreen regardless because UV exposure is cumulative. As the index climbs into High, Very High, and Extreme, add shade, protective clothing, and more frequent reapplication. The Skin Cancer Foundation links each tier to specific sun-safe behaviors.
r/SkincareAddiction: 'My app shows UV 3 on an overcast winter day — do I genuinely need sunscreen at that level?'