UV index 5: how long until skin burns?
UV index 5 falls in WHO's Moderate category. Without protection, very fair skin (type I) can start to redden in about 20 minutes, and olive skin (type IV) in about 60 minutes. These are rough estimates, not safe times.
Moderate · 3–5 Protection needed: midday shade, shirt, hat, sunglasses and sunscreen.
A warning, not a safe time. Redness shows up hours later.
Minutes to first redness by skin type
| Type IAlways burns, never tans; very pale skin, often freckles or red hair | about 20 minutes |
|---|---|
| Type IIUsually burns, tans with difficulty; fair skin, often light eyes | about 25 minutes |
| Type IIISometimes burns, tans gradually; light to light olive skin | about 40 minutes |
| Type IVRarely burns, tans easily; olive or light brown skin | about 60 minutes |
| Type VVery rarely burns, tans darkly; naturally brown skin | about 80 minutes |
| Type VIAlmost never burns; naturally dark brown to black skin | more than 2 hours |
What WHO advises at this level
From UV 3 upward, WHO says protection is needed. Seek shade during the midday hours, wear a shirt, a broad-brimmed hat and sunglasses, and apply broad-spectrum sunscreen of at least SPF 15 to skin you cannot cover. Use these measures together. Unprotected fair skin can start to redden in 20 to 45 minutes.
When and where you see this level
UV 5 is a common summer midday value in Scandinavia and Scotland, and a typical May or August value in central Europe. Further south you meet it on hazy or partly cloudy days, or about two hours from midday.
What this means if you want a tan
At UV 5 very fair skin can start to redden in about 20 minutes. Tanning and burning come from the same UV, so a tan always comes with some skin damage. Gradual tanning still adds up; avoiding sunburn is the most important goal.
Frequently asked questions
How long does it take to burn at UV 5?
Rough estimates for unprotected skin at UV 5: type I: about 20 minutes; type II: about 25 minutes; type III: about 40 minutes; type IV: about 60 minutes. Redness usually appears hours later, and some people burn sooner. These are not safe times.
Is UV 5 high?
Moderate (3–5). From UV 3 upward, WHO says protection is needed. Seek shade during the midday hours, wear a shirt, a broad-brimmed hat and sunglasses, and apply broad-spectrum sunscreen of at least SPF 15 to skin you cannot cover. Use these measures together. Unprotected fair skin can start to redden in 20 to 45 minutes.
Can you tan at UV 5?
At UV 5 very fair skin can start to redden in about 20 minutes. Tanning and burning come from the same UV, so a tan always comes with some skin damage. Gradual tanning still adds up; avoiding sunburn is the most important goal.
Sources
- WHO, WMO, UNEP, ICNIRP (2002): Global Solar UV Index – A Practical Guide
- WHO (2022): Radiation – The ultraviolet (UV) index, questions and answers
- ICNIRP with ILO and WHO (2007): Protecting Workers from Ultraviolet Radiation (skin types and SED, Table 1)
- Journal of Cosmetic Dermatology: Fitzpatrick skin phototypes with typical minimal erythema dose (Table 1, after Fitzpatrick 1988 and Pathak 1987)
- CIE: Standard Erythema Dose, a Review (1 SED = 100 J/m²)