What is the Ultraviolet (UV) Index?

Sun Protection | Sun Dangers | The UV Index | UV Radiation
The Sun & Skin Cancer | Skin Self-Exam | Sun Protection Poster (pdf)

While some exposure to sunlight can be enjoyable, too much is dangerous, causing immediate effects like blistering sunburns, as well as longer-term problems like skin-cancer and cataracts. Developed by the National Weather Service (NWS) and the Environmental Protection Agency (EPA), the Ultraviolet (UV) Index provides important information to help you plan your outdoor activities in ways that prevent overexposure to the sun's rays.

The UV Index predicts exposure levels on a 0 - 10+ scale, where 0 indicates a minimal risk of overexposure, and 10+ means a very high risk of overexposure. Calculated on a next-day basis for dozens of cities across the U.S. by the National Weather Service, the UV Index takes into account clouds and other local conditions that effect the amount of UV radiation reaching the ground in different parts of the country.

When the index is High or Very High, try to minimize your outdoor activities between the peak hours of 10:00 a.m. and 4:00 p.m. when the sun is most intense. When the index is 10 or higher, stay indoors if possible, otherwise be sure to take all the other necessary precautions. Watch closely for the UV Index reports in your local newspapers and on television. For more information call 1-800-296-1996.

Resource: U.S. Environmental Protection Agency, Air and Radiation, 6205J, EPA 430-H-94-003

Sun Protection | Sun Dangers | The UV Index | UV Radiation
The Sun & Skin Cancer | Skin Self-Exam | Sun Protection Poster (pdf)