An official website of the United States government.

Due to a lapse in appropriations, EPA websites will not be regularly updated. In the event of an environmental emergency imminently threatening the safety of human life or where necessary to protect certain property, the EPA website will be updated with appropriate information. Please note that all information on the EPA website may not be up to date, and transactions and inquiries submitted to the EPA website may not be processed or responded to until appropriations are enacted.

We've made some changes to EPA.gov. If the information you are looking for is not here, you may be able to find it on the EPA Web Archive or the January 19, 2017 Web Snapshot.

UV Index Mobile App

Envirofacts has developed applications for use with mobile devices that can provide practical information for users who are “on the go”. Please check back periodically as new applications are developed.

Moblie UV Banner

The Ultraviolet (UV) Index predicts the ultraviolet radiation levels on a 1-11+ scale. The UV Index provides a daily forecast of the expected intensity of UV radiation from the sun. To assist users in utilizing the UV Index forecast, EPA provides two options for viewing this information with your mobile device.