EPA SunWise: Revised UV Index

EPA Launches Revised UV Index

May 2004
EPA, in partnership with the National Weather Service, has adopted new international guidelines for UV Index reporting based on recommendations from the World Health Organization. We encourage all organizations that provide the UV Index to the public to use the new guidelines. This page provides information and links to familiarize you with the new UV Index.

Frequent Questions

What is the UV Index?

The Ultraviolet (UV) Index, developed in 1994 by the National Weather Service (NWS) and the US Environmental Protection Agency (EPA), helps Americans plan outdoor activities to avoid overexposure to UV radiation and thereby lower their risk of adverse health effects. EPA and NWS report the Index as a prediction of the UV intensity at noon, though the actual UV level rises and falls as the day progresses.

EPA offers UV Index Forecasts by zip code or city & state.

Why is the UV Index changing?

Guidelines for Global UV Index reporting were recommended in 2002 by the World Health Organization, the World Meteorological Organization, the United National Environment Programme and the International Commission on Non-Ionizing Radiation Protection in order to bring worldwide consistency to UV reporting.

When will the changes to the UV Index occur?

EPA officially announced the launch of the revised UV Index on May 26, 2004, prior to the Memorial Day weekend. EPA's and NWS's websites have been updated to reflect the new guidelines.

How is the UV Index being revised?

Previously the UV Index was reported on a scale of 0 to 10+, with 0 representing "Minimal" and 10+ representing "Very High." The new global scale (see below) now uses a scale of 1 (representing "Low") to 11 and higher (representing "Extreme"), a new color scheme, revised exposure categories, and different breakpoints between exposure categories. (A UV Index of "0" is still possible, but there is no corresponding health message because there either is no UV at that level or the amount is trivially small.)

Resources

You will need Adobe Acrobat Reader, available as a free download, to view some of the files on this page. See EPA's PDF page to learn more about PDF, and for a link to the free Acrobat Reader.

A Guide to the UV Index (PDF, 8 pp., 2.1 MB) - Brochure developed by EPA for meteorologists, educators and public health officials on recommendations for reporting the UV Index.

UV Safety: The Global Solar UV Index (PDF, 1 p., 109 KB) - Poster displaying the UV index scale and action steps.

Look Up Your UV Index by Zip Code or City & State

The Global Solar UV Index (PDF, 18., 429 KB) - Practical guide published by the World Health Organization and other international groups under the INTERSUN program.

The World Health Organization's INTERSUN program has developed a graphics package, including a UVI logo, an international color code for different UVI values, and a choice of ready-made graphics for reporting the UVI and sun safety messages. The materials may be downloaded and used free of charge.

An overview of the available graphics is available (PDF, 17 pp., 460 KB).

GIF images are available for downloading.

To request a CD-ROM containing formats other than GIF, please write to uvinfo@who.int

Press Kits

UV Index Press Kits are available upon request. Please send requests to monroe.scott@epa.gov or call 202-343-9712

Contacts

General Information:
Scott Monroe, 202-343-9712
Monroe.Scott@epa.gov

For Meteorologists:
Jason Samenow, 202-343-9327
Samenow.Jason@epa.gov

For Public Health Professionals and questions about EPA's SunWise Program:
Paula Selzer, 202-343-9361
Selzer.Paula@epa.gov

National Weather Service:
Craig Long, 301-763-8071 ext 7557
Craig.Long@noaa.gov