Nationwide testing of mobile emergency alert system will take place later this month.
The alert will be sent to cell phones between 18:00 and 19:00 on Sunday, November 25th.
Civil defense said that about half of all mobile phones will receive the alert.
A similar test last November reached about a third of all mobile phones.
The Department of Civil Defense and Emergency Administrator, Sarah Stewart-Black, said the annual review of the system helped ensure that it works efficiently, helping public awareness of what to expect and how it works.
"By running this test and asking people to be aware of alerts, we can test our systems, cell towers, and your phone's ability to receive an emergency mobile alert," said Stuart-Black.
"It's just a test, but when emergencies happen, emergency mobile alert will be a vital channel to help keep our communities safe.
"Not all phones are now able to receive the alerts, so we need people to keep an eye on it: if you get alerted, tell your neighbors, whanau, your colleagues."
The system can geo-target areas and has not been affected by network congestion.
"The national test last year was not only important in spreading the system's awareness, but also in highlighting issues with several devices so we could work with them with manufacturers," said Ms. Stewart-Black.
The notice will include a link to the Civil Defense Web site, where the recipients will be able to complete a survey to help inform further improvements to the system.
Learn more about emergency mobile alerts, including if your mobile phone is compatible, at [www.civildefence.govt.nz the Civil Defence website].