Your cell phone will receive an emergency alert test this week: Here's when and why

Americans around the country will see their phones light up this week following a nationwide test of emergency alert systems.

The Federal Emergency Management Agency and the Federal Communications Commission are planning to test both the Emergency Alert System (EAS) and Wireless Emergency Alerts (WEA) on Wednesday, October 4, at 2:20 p.m. Eastern. The test will be conducted in two parts, with one set to go to cell phones and the other to radio and TV stations.

FEMA says the alert will have a unique tone and vibration to make the alert accessible to all recipients. Phones should receive the message only one time in the 30 minutes after the test begins on Wednesday.

"The purpose of the Oct. 4 test is to ensure that the systems continue to be effective means of warning the public about emergencies, particularly those on the national level," FEMA and the FCC explained in a statement.

The WEA test will go to Americans’ cell phones and will include one text message that will read, "THIS IS A TEST of the National Wireless Emergency Alert System. No action is needed." 

Phones with Spanish as the default language setting will receive a message saying "ESTA ES UNA Prueba del Sistema Nacional de Alerta de Emergencia. No se necesita acción."

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The agency noted this will be the third nationwide test of the system, although it will be just the second test that has gone to all cell phones since the system was established in 2012.

The Emergency Alert System (EAS) will send messages to radios and televisions at the same time the WEA test is carried out.

It will last for approximately one minute and be conducted with the participation of radio and TV broadcasters, cable systems, satellite radio and TV providers and wireline video providers. The EAS test will be the seventh nationwide test of the emergency alert system.

The EAS message will state: "This is a nationwide test of the Emergency Alert System, issued by the Federal Emergency Management Agency, covering the United States from 14:20 to 14:50 hours ET. This is only a test. No action is required by the public." 

FEMA and the FCC are coordinating with EAS participants, wireless providers, emergency managers and others in preparation for the test to minimize confusion and maximize the public safety value of the test.

The agencies have set a backup testing date of October 11, which will be used if there is widespread severe weather or other significant events occurring on October 4 that derail the planned test.