UV Index Scale
The UV Index scale used in the United States conforms with international guidelines for UVI reporting established by the World Health OrganizationExitLearn how to read the UV index Scale to help you avoid harmful exposure to UV radiation.
0 to 2: Low
3 to 7: Moderate to High
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.
8+: Very High to Extreme
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.
The Shadow Rule
An easy way to tell how much UV exposure you are getting is to look for your shadow:
- If your shadow is taller than you are (in the early morning and late afternoon), your UV exposure is likely to be lower.
- If your shadow is shorter than you are (around midday), you are being exposed to higher levels of UV radiation. Seek shade and protect your skin and eyes.