Civil Defence and the Fire Service in Napier are testing 16 sirens in the city at midday on Sunday.
They will sound on and off for about five minutes.
Civil Defence says the decision to test all sirens in the city, follows local disquiet over the possibility of an earthquake or tsunami hitting the region.
A portable warning system is also being between tested by Hastings CD from 11am - 1pm in the coastal communities of Haumoana, Te Awanga and Clifton.
