Virtually every phone in the country will blare an emergency siren at 2pm AEST on Monday 27 July as part of the first Australia-wide test of a new national warning system called AusAlert.Most phones, and some smartwatches and tablets, will receive a pop-up notification and an alert sound that cannot be silenced – even if your device is on “do not disturb” or silent mode.What is AusAlert?AusAlert is Australia’s new national warning system, which will send emergency messages to mobile devices during local and widespread disasters.Authorities currently use SMS texts to alert people about safety information. The new system will instead send a mass broadcast via mobile phone towers, with an alert popping up on devices, similar to a phone notification.It will launch nationally in October, months after the national test.What will happen during the national test?“On Monday 27 July 2026, a test alert will be sent to all mobile devices in Australia. This includes most phones, and some smart watches and tablets,” the National Emergency Management Agency (Nema) advises.Users will hear a siren and see a pop-up notification on their phone, which will look different depending on the device, but with text including “TEST MESSAGE” and “NO ACTION IS REQUIRED”.Video of the AusAlert test“What people should expect to hear is a siren that will last for about 10 seconds,” said Pat Hetherington, the interim coordinator general at Nema.He said it would be “loud enough to get people’s attention” but quieter than a fire alarm.“It will be noticeable, but it won’t won’t be too over the top.”What time is the AusAlert test around Australia?There have been local tests, but Monday will be the first nationwide test, occurring at 2pm AEST, which is: