The long-awaited AusAlert system will undergo a national test on Monday, July 27, before it officially comes online in October.
The $132 million communications network allows emergency messages to be targeted to within 160 metres, meaning individual streets can be told to evacuate or prepare.
It was originally supposed to be delivered by the end of 2024, but was hit with a series of delays.
Local tests will first be conducted in all states and territories over June, with messages to be sent to residents of Majura, ACT; Launceston, Tasmania; Port Douglas, Queensland; Liverpool, NSW; Geelong, Victoria; Tennant Creek, NT; Goomalling, WA; Port Lincoln, South Australia; and a cross-border test around Queanbeyan, on the NSW-ACT border.
Two levels of alerts can be sent - a critical alert which will warn of imminent threat to life and property, and a priority alert for watch and act or advice warnings.
While users will be able to opt out of priority alerts, critical alerts will appear on the home screens of compatible devices accompanied by a loud sound, even if the phone is set to silent.
Officials believe around 90 per cent of all phones will be compatible.
Emergency Management Minister Kristy McBain said the new system would help deliver more targeted, timely warnings.
"This is an important project that will help us and emergency services organisations warn people when they are in harm's way, saving lives and protecting property during a disaster," she said in a statement.
