Anger was allayed by Festival organisers offering ticket exchanges for another night and several people posted later to say they had gone in the rain and had a good time.
Between 60mm and 90mm of rain pelted down over the Auckland region in the first six hours of today, Civil Defence said - a month's worth of rain.
About 200 weather-related calls have come in to the fire service since midnight.
The festival spokeswoman said she hoped people would be able to experience "the magical world of Power Plant" during the remainder of the season which runs until March 19.
Ticket holders for tonight have three options:
Option One: Exchange your tickets to an alternative Night of Power Plant
To organise an alternative time for Power Plant, please return to the box office where you made your original purchase or, if you booked via phone or online, please phone Ticketmaster on (09) 951 2501 between 9am and 5pm or email customer.help@ticketmaster.co.nz. You will not be charged another booking fee and your request for an exchange will be dealt with promptly.
Option Two: Exchange your Power Plant ticket for a ticket for tonight's performance of RICE
If you wish to exchange your Power Plant ticket for a RICE ticket tonight 11 March, please go to the Aotea Centre Box office between 6.30pm and 7.45pm with your Power Plant ticket in hand and an immediate exchange can be made. The show starts at 8pm, there is a lock out for late comers.
Option Three: Receive a Refund
Please return to the box office where you made your original purchase or, if you booked via phone or online, please phone Ticketmaster on (09) 951 2501 between 9am and 5pm, or email customer.help@ticketmaster.co.nz.