The UV index runs from 0 to 11 and above, and it tells you how strong the sun is where you are right now. At 3 to 5 the exposure is moderate. At 6 to 7 it is high, at 8 to 10 very high, and 11 or more is extreme.
Across southern Europe in summer, midday readings sit at 8 or higher for hours. At that level unprotected skin can redden in fifteen to twenty minutes, and the damage adds up over the years whether or not you burn.
The simple rule: when the index is 6 or above, cover the skin that stays out. A long-sleeve UPF shirt, a wide-brim hat and UV400 sunglasses handle the exposure without the guesswork of reapplying lotion. Check the index before a day outside the same way you check the forecast.
