Some exposure to sunlight can be enjoyable; however, too much could be dangerous. Overexposure to the sun's ultraviolet (UV) radiation can cause immediate effects such as sunburn and long-term problems such as skin cancer and cataracts.

The UV Index, which was developed by the National Weather Service and the U.S. Environmental Protection Agency (EPA), provides important information to help you plan your outdoor activities to prevent overexposure to the sun's rays.

The UV Index provides a daily forecast of the expected risk of overexposure to the sun. The Index predicts UV intensity levels on a scale of 1 to 11+, where low indicates a minimal risk of overexposure and 11+ means an extreme risk. Calculated on a next-day basis for every ZIP code across the United States, the UV Index takes into account clouds and other local conditions that affect the amount of UV radiation reaching the ground in different parts of the country.

UV Index Number Exposure Level
0 to 2: Low
3 to 5: Moderate
6 to 8: High
8 to 10: Very High
11+: Extreme

By taking a few simple precautions, you can greatly reduce your risk of sun-related illnesses. Consider the following steps:

Limit your time in the sun between 10 a.m. and 4 p.m.
Whenever possible, seek shade.
Use a broad spectrum sunscreen with an SPF of at least 15.
Wear a wide-brimmed hat and if possible, tightly woven, full-length clothing.
Wear UV-protective sunglasses.
Avoid sunlamps and tanning salons.
Watch for the UV Index daily.

While you should always take precautions against overexposure to the sun, please take special care to adopt the safeguards when the UV Index predicts levels of moderate or above. Watch for UV Index reports in your local newspapers and on NBC Weather Plus.

For more information on the UV Index, visit the U.S. Environmental Protection Agency's Web site at www.epa.gov/sunwise/