The Northland Regional Council has announced tsunami sirens will be tested on September 30, as part of twice-yearly checks.

The siren network – from Te Hapua in the north to Mangawhai in the south and Ruawai in the west – will sound twice: at 10am for 10 minutes and again at 10:30am for 30 seconds, and will be monitored for any faults.

Northland has 190 outdoor tsunami sirens, more than any other region in the country with 109 sirens in the Whangarei district, 60 in the Far North and 21 in the Kaipara district.

New plug-in indoor tsunami sirens – synchronised with the outdoor sirens – will also be part of the daylight saving checking for the first time.

The council is urging new indoor siren owners to monitor their units during testing time. They are advised to check if the unit is sounding correctly and if its accompanying blue flashing light is working.

“It’s important to remember that indoor sirens must not be turned off during testing (or a genuine tsunami warning),” Victoria Harwood, spokesperson for the Northland Civil Defence Emergency Management (CDEM) Group said.