A state of emergency was declared on Friday night, with NZ's National Institute of Weather and Atmospheric Research reporting that an entire summer's worth of rain had fallen in a 24-hour period.
A show by Elton John at the 40,000 capacity Eden Park venue was cancelled on Friday with 11,000 people already in the stadium, and the following night's show was also swiftly shelved. Meanwhile, a number of international flights carrying incoming musicians were turned around mid-flight after the runway and terminal buildings at Auckland airport were flooded.
Among those affected were Halestorm, who posted: "Due to the crazy weather and flooding that happened this week, Arejay and Josh as well as half of our mighty crew were turned around mid-flight to Auckland, and sent back to the United States. The boys are stuck there with no flights available, and no way to get to NZ in time for our shows.
"We are heartbroken that we have to postpone our reunion with all of our Kiwi fans! We adore you and your beautiful country, and are sending all our love to everyone affected by the floods. See you all again soon!"
ZZ Top's Summer Concert Series show in Whitianga, 120 miles south-east of Auckland, has also been cancelled. The show, which also featured Pat Benatar & Neil Geraldo, Stone Temple Pilots and Aussie rockers The Angels, was due to take place this weekend.
The event's organisers wrote, "Due to the current weather event that is still playing out in the upper North Island, the continued disruption around road access in and out of the Coromandel Peninsula, and following information received from authorities, we have made the heart-breaking decision to cancel this weekend’s Whitianga Summer Concert.
"This was our only option given our priority must always be to protect the health and safety of both our crew that are tasked with setting up and delivering the show, and of course all our concert goers who predominantly travel to get to the show."
Further Summer Concert Series shows in the North Island town of Taupō and in the South Island's Gibbston Valley are still scheduled to proceed, with the same line-up.