UV Index Category Checker
Enter the UV index from your forecast to see its WHO category and what WHO and the EPA say to do at that level, quoted word for word.
UV index category
- WHO: "REPORTING BURN TIMES IS NOT RECOMMENDED. Hence, relating UVI values to “time to burn” or “safe tanning time” sends out the wrong message to the public."
- FDA: "This is not true because SPF is not directly related to time of solar exposure but to amount of solar exposure."
A fraction is rounded up, so a reading is never put in a lighter category. Sources: WHO, EPA, WHO UV Index guide.
Category, not a countdown
The UV index is a forecast of how strong the sun’s burning UV will be at its daily peak. WHO and the EPA turn it into a category and an action: from 3 up, protection is needed; from 8 up, extra protection. That is what this checker shows. It does not turn the number into minutes, because WHO advises against burn times: people read them as a safe amount of unprotected sun.
WHO’s list of measures puts shade and clothing first: “Sun protection is best achieved by seeking shade and wearing clothes rather than applying sunscreens.” Use sunscreen on the skin clothes cannot cover, and reapply it.
Frequently Asked Questions
What are the UV index categories?
WHO groups the index into five exposure categories: Low (0 to 2), Moderate (3 to 5), High (6 to 7), Very High (8 to 10) and Extreme (11 and above). WHO reports the index as a whole number; this checker rounds any fraction up, so 2.1 is read as 3, Moderate.
Why doesn't it tell me how many minutes I can stay out?
WHO's guide to the UV index says: "REPORTING BURN TIMES IS NOT RECOMMENDED. Hence, relating UVI values to “time to burn” or “safe tanning time” sends out the wrong message to the public." This page used to print a time to burn for each skin type; it no longer does.
Does a higher SPF let me stay out longer?
No. The FDA says: "Some people incorrectly believe that SPF relates to time of solar exposure. For example, some people believe that, if they normally get sunburned in one hour, then an SPF 15 sunscreen allows them to stay in the sun for 15 hours (e.g., 15 times longer) without getting sunburn. This is not true because SPF is not directly related to time of solar exposure but to amount of solar exposure." Reapply on the FDA rule instead: "Reapply sunscreen at least every two hours, and more often if you're sweating or swimming."
What about water, sand, snow or altitude?
They add UV. WHO's guide says fresh snow can reflect as much as 80% of UV radiation and that UV rises 10% to 12% with every 1,000 meters of altitude. The Sunburn Risk Category tool on this site adds those figures to the forecast before it picks the category.
General information, not medical advice. The words in quotation marks are WHO’s, the EPA’s and the FDA’s, checked on their sites on October 6, 2026.