Northland tsunami siren testing no April Fools' joke

One of the tsunami sirens in Northland which will be tested on April Fools Day. Photo/Supplied

Northland's tsunami siren testing is no joke - despite being carried out on April Fools' Day.

The region's 184 sirens, from Te Hapua to Mangawhai, will sound twice on Sunday, firstly at 12pm for 10 minutes and then again at 12.30pm for 30 seconds.

The sirens are tested twice a year to coincide with the beginning and end of daylight saving to check for any faults.

Northland Civil Defence group spokesman Murray Soljak said they were aware of the clash with April Fools' Day and Easter Sunday, and as a result, decided to delay the testing times from the usual 9.20am and 10am times.

Mr Soljak said the group wanted to make sure the sirens sounding was clear of church services being held for Easter Sunday.

"The April Fools' Day tradition is that it finishes at midday."

He said the group did consider moving the testing to a different day - Auckland had opted to test sirens on Saturday - but said the Northland group decided to stick with the connection the testing has with daylight saving.

He said the siren tests were definitely not a prank, and provided an opportunity for people to familiarise themselves with the sound and work out the route to safety they might take if the tsunami threat was real.

Daylight saving ends at 3am Sunday, when clocks go back an hour.