What Is the UV Index?

The UV Index is a scale from 0 to 11+ that measures the strength of ultraviolet radiation and indicates how quickly unprotected skin can burn.

Quick Answer

A higher UV Index means stronger UV radiation and a higher risk of sunburn and skin damage. At a UV Index of 3 or higher, sun protection such as sunscreen, shade, or protective clothing is recommended.

UV Index Scale Explained

UV Index Risk Level Recommended Protection
0–2 Low No protection needed for most people
3–5 Moderate Sunscreen SPF 30+, sunglasses
6–7 High Limit midday sun, protective clothing
8–10 Very High Seek shade, reapply sunscreen often
11+ Extreme Avoid direct sun exposure

What Affects the UV Index?

  • Time of day (highest around solar noon)
  • Latitude and season
  • Altitude (UV increases ~10% per 1,000 m)
  • Cloud cover and surface reflection
  • Ozone concentration

Why the UV Index Matters

Monitoring the UV Index helps reduce the risk of sunburn, premature skin aging, and long-term skin damage, especially for fair or sensitive skin types.

How SunSafe Uses the UV Index

SunSafe tracks real-time UV data for your location and combines it with your skin type to estimate time to sunburn, vitamin D intake, and safe tanning duration.

Frequently Asked Questions

Is UV Index 3 dangerous?

UV Index 3 is considered moderate. Sunburn is possible after prolonged exposure, especially for fair skin types.

Can you tan when UV Index is low?

Yes, tanning can occur at lower UV levels, but it happens more slowly and still requires protection.

Use the UV Index to Tan Safely

SunSafe tracks the real-time UV Index for your location and combines it with your skin type to estimate safe sun exposure and time to sunburn.

Download SunSafe to track today’s UV Index →