The 150-plus tsunami sirens stringing Northland's coast will be sounded when daylight saving starts later this month - not to herald summer, but to ensure the warning system works.
Coming soon after a tsunami warning following an earthquake off East Cape, the six-monthly test is timely.
The 150-plus Northland sirens will sound on the morning of Sunday, September 25, as part of the regular twice-yearly checks.
Victoria Randall, of the Northland Civil Defence Emergency Management Group, said the sirens will sound twice - at 9.20am for 10 minutes and at 10am for 30 seconds.
"Civil Defence community groups or local council staff will monitor the sirens at these times, reporting any faults for repair," Ms Randall said.