UV Index & Sun Protection Reference
The official categories and actions in one place, quoted word for word from WHO, the EPA, the FDA and the American Academy of Dermatology, with a link to each. General information, not medical advice.
UV index categories and what to do
| Category | UV index | WHO says | EPA says |
|---|---|---|---|
| Low | 0 to 2 | “You can safely enjoy being outside!” | “No protection needed. You can safely stay outside using minimal sun protection.” |
| Moderate | 3 to 5 | “Seek shade during midday hours! Slip on a shirt, slop on sunscreen and slap on hat!” | “Protection needed. Seek shade during late morning through mid-afternoon. When outside, generously apply broad-spectrum SPF-15 or higher sunscreen on exposed skin, and wear protective clothing, a wide-brimmed hat, and sunglasses.” |
| High | 6 to 7 | “Seek shade during midday hours! Slip on a shirt, slop on sunscreen and slap on hat!” | “Protection needed. Seek shade during late morning through mid-afternoon. When outside, generously apply broad-spectrum SPF-15 or higher sunscreen on exposed skin, and wear protective clothing, a wide-brimmed hat, and sunglasses.” |
| Very High | 8 to 10 | “Avoid being outside during midday hours! Make sure you seek shade! Shirt, sunscreen and hat are a must!” | “Extra protection needed. Be careful outside, especially during late morning through mid-afternoon. If your shadow is shorter than you, seek shade and wear protective clothing, a wide-brimmed hat, and sunglasses, and generously apply a minimum of SPF-15, broad-spectrum sunscreen on exposed skin.” |
| Extreme | 11 and above | “Avoid being outside during midday hours! Make sure you seek shade! Shirt, sunscreen and hat are a must!” | “Extra protection needed. Be careful outside, especially during late morning through mid-afternoon. If your shadow is shorter than you, seek shade and wear protective clothing, a wide-brimmed hat, and sunglasses, and generously apply a minimum of SPF-15, broad-spectrum sunscreen on exposed skin.” |
Categories: WHO’s Table 1 (WHO, Global solar UV index: a practical guide (2002)). Actions: WHO, Radiation: The ultraviolet (UV) index and EPA, UV Index Scale; WHO and the EPA use the same three bands (up to 2, 3 to 7, 8 and above). WHO reports the index as a whole number; the UV Index Category Checker rounds any fraction up.
WHO’s protective measures
- “Limit time in the midday sun.”
- “Seek shade.”
- “Wear protective clothing.”
- “Wear a broad brimmed hat to protect the eyes, face, ears and neck.”
- “Wear wraparound-style sunglasses that provide 99 to 100% UV-A and UV-B protection.”
- “Use broad-spectrum sunscreen on skin areas that cannot be covered by clothes.”
“Sun protection is best achieved by seeking shade and wearing clothes rather than applying sunscreens.” “Sunscreens should not be used for extending time spent in the sun.” WHO, Ultraviolet radiation (fact sheet)
What adds UV
- Altitude: “With every 1000 metres increase in altitude, UV radiation levels increase by 10% to 12%.”
- Ground reflection: “fresh snow can reflect as much as 80% of UV radiation, dry beach sand about 15% and sea foam about 25%.”
WHO, Global solar UV index: a practical guide (2002). The Sunburn Risk Category tool adds the top of each figure to your forecast before it picks a category.
Skin types (WHO)
| Type | Burns in the sun | Tans after having been in the sun |
|---|---|---|
| I | Always | Seldom |
| II | Usually | Sometimes |
| III | Sometimes | Usually |
| IV | Seldom | Always |
| V | Naturally brown skin | |
| VI | Naturally black skin | |
“Fair-skinned people suffer more from sunburn and have a higher risk of skin cancer than dark-skinned people; however, darker-skinned people also develop skin cancers.” WHO, Ultraviolet radiation (fact sheet)
Table 2 of WHO, Global solar UV index: a practical guide (2002), adapted there from Fitzpatrick.
Sunscreen rules
- Amount: “An average-sized adult or child needs at least one ounce of sunscreen (about the amount it takes to fill a shot glass) to evenly cover the body from head to toe.”
- Reapply: “Reapply sunscreen at least every two hours, and more often if you're sweating or swimming.” The AAD: “To remain protected when outdoors, reapply sunscreen every two hours, and immediately after swimming or sweating.”
- SPF is not a timer: “This is not true because SPF is not directly related to time of solar exposure but to amount of solar exposure.”
- Which kind: “Use broad spectrum sunscreens with sun protection factor (SPF) values of 15 or higher regularly and as directed.” The AAD: “Choose a sunscreen that has an SPF of 30 or higher, is water resistant, and provides broad-spectrum (UVA and UVB rays) coverage.”
- Expiry: “That means a sunscreen product that doesn’t have an expiration date should be considered expired three years after purchase.”
- Babies: “Sunscreen is not recommended for infants under six months old.”
FDA, Sunscreen: How to Help Protect Your Skin from the Sun; American Academy of Dermatology, How to apply sunscreen.
Frequently Asked Questions
Why is there no table of minutes per skin type?
There used to be. 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." The table was removed on October 6, 2026.
Does darker skin mean less protection is needed?
WHO says: "Fair-skinned people suffer more from sunburn and have a higher risk of skin cancer than dark-skinned people; however, darker-skinned people also develop skin cancers." The categories and actions on this page apply to everyone.
Where does each line come from?
Every sentence in quotation marks is copied from the WHO, EPA, FDA or American Academy of Dermatology page linked beside it, checked on October 6, 2026. The category rows are produced by the same function as the UV Index Category Checker, so the two cannot disagree.
General information, not medical advice. See a doctor or dermatologist about your own skin, moles or sun sensitivity, and follow your sunscreen’s label.
Use it with
- UV Index Category Checker: put today’s forecast in its category.
- Sunscreen Amount Calculator: how much one full coat takes.
- Understanding the UV Index: what the scale means and what raises it.