Home /
Guides / What UV index is safe? The UV scale explained
What UV index is safe? The UV scale explained
☀ 4 min read · Sun & tanning guide
The UV index runs from 0 to 11+. There's no truly “safe” level, but protection is advised from UV 3 upward. Here's what each band means.
The global UV index is a standardised scale from the World Health Organization that tells you the strength of UV radiation at ground level. The higher the number, the faster unprotected skin can be damaged. It's the single most useful number for planning sun - far more so than temperature.
The UV index bands
- 0–2 · Low (green): Minimal risk. Safe for most people; fair skin can still tan slowly.
- 3–5 · Moderate (yellow): Protection starts here. Wear SPF, use shade midday. A common tanning range.
- 6–7 · High (orange): Burning is faster. SPF 30+, hat, sunglasses, limit midday sun.
- 8–10 · Very High (red): Take extra care. Seek shade, cover up, minimise midday exposure.
- 11+ · Extreme (violet): Unprotected skin can burn very quickly. Avoid the sun around midday.
The threshold that matters
UV 3 is the line where the WHO recommends sun protection - regardless of temperature or cloud. Below 3, risk is low; at 3 and above, take it seriously.
Why the number beats the weather
UV doesn't track how hot or bright it feels. You can have UV 7 on a cool, cloudy day (see cloudy-day UV) or low UV on a warm evening. Reflection off water, sand and snow, plus altitude, all push your effective exposure higher than the raw number.
Do it in Sunhalo
Sunhalo shows the live UV index for your exact location, colour-coded by band, with a plain-language risk label (“Very High UVI Risk - seek shade”) and an hourly timeline so you can see when UV crosses 3, peaks, and drops back. It turns the scale into an actual plan for your day.
Frequently asked
Is UV index 5 safe?
UV 5 is Moderate. It's a common tanning level but protection is advised - wear SPF 30+, seek shade around midday and keep sessions reasonable.
What UV index causes sunburn?
Any level above 2 can cause sunburn with enough exposure, but risk rises sharply from UV 6 and above, especially for fair skin.
What is a high UV index?
UV 6-7 is High, 8-10 is Very High, and 11+ is Extreme. From UV 8 up, the WHO advises actively seeking shade around midday.
Keep reading
Sunhalo provides educational estimates, not medical advice, and is not a medical device. Any tan is a sign of UV damage. Medications, altitude, and reflection off water, sand or snow all change your real risk. When in doubt, choose shade.
