Don't be alarmed if you hear a tsunami siren tomorrow - Auckland Civil Defence is performing its twice-yearly checks on the warning system.
The tests, timed to coincide with the end of daylight savings, will take place at midday.
Auckland Civil Defence emergency management operations head Aaron Davis said the public should not be alarmed, and were not required to do anything.
"We run these tests to check operational performance and familiarise residents with the siren tones," he said.
"The sirens are just one of a number of technology-based public warning systems that Auckland Civil Defence has in place for the entire region to better prepare for natural disasters."