What you need to know
The tests are to ensure that the systems are still effective in communicating and warning the public about emergencies, especially those on a national level, according to FEMA.
The wireless emergency alerts will be sent to cell phones in English or Spanish, depending on the phone settings.
The emergency system will send alerts to radios and televisions.
Editor's note: The original story has been updated to correct an error. The test will take place at 1:20 p.m. CST.