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 Alert

It's critical to know the level of ultraviolet (UV) radiation before you plan outdoor activities. The UV Alert system issues a notification when the level of solar UV radiation is predicted to be higher than normal, and consequently the risk of overexposure is greater. The UV Alert provides SunWise action steps that you should take to reduce risk of overexposure.

We encourage you to check the UV Index daily or to sign up using our free EnviroFlash service to receive the UV Alert by email.

Be SunWise: Sign up for UV Alerts !