Nationwide mobile test alert being sent tonight, expect a 'loud sound'

The annual nationwide test of New Zealand's Emergency Mobile Alert system is happening tonight. 

The alert will be sent out to around four million Kiwis' phones between 6pm and 7pm.

Anyone who has a mobile phone that is capable of receiving the alerts can expect to hear a loud sound after which a notification will pop up.

The test alert will link to the Civil Defence website, where people can choose to fill out a survey about how they experienced the alert.

Last year six in ten New Zealanders received the alert, and that number is expected to be higher this time round.