Fierce winds and heavy rain lashed homes in the Auckland region overnight - uplifting roofs, toppling over shipping containers and damaging The Cloud at the waterfront.
Up to 1700 lightning strikes were recorded and emergency services were dealing with callouts from all around the city and down towards the south of Waikato.
At least one house was struck by lightning in Auckland.
Thunder, lightning and heavy rain started to pound the area from about 8pm. The NZ Fire and Emergency services responded to about 20 callouts from around Auckland and Waikato.
In downtown Auckland, part of The Cloud's awning has been torn off and left in tatters.
A spokeswoman for Regional Facilities Auckland - the Auckland Council body that manages the building - said team members were on site assessing the damage.
She said there were no bookings at The Cloud until the end of September.
Further down the road, at the Ports of Auckland, huge shipping containers looked more like Lego blocks as some had toppled over each other in the high winds.
Northern fire communications shift manager Daniel Nicholson said they were needed at five houses in the suburb of St Heliers alone, where roofs were pulled clean off from some properties.
A pre-school on Bermuda Rd was badly damaged.
Nicholson said: "We got called to a house in Kumeu that got struck by lightning.''
Nothing was too badly damaged at that particular house, in Riverhead, and no one was injured at any of those call-outs, he said.
Residents who spoke to the Herald said they did not know which house had been affected, but acknowledged that it had been a loud night.
One resident said: "We got some good thunder last night - it was lovely.''
Photos and videos captured by members of the public from different parts of Auckland show trees and homes damaged and debris littering the streets.
An East Auckland man told TVNZ he got a shock when his neighbour's roof flew into his backyard.
"When the rain just started - there was a mighty bang!
"And the roof blew off and the doors blew in and we were all of a sudden totally exposed to this weather. It was just amazing.''
MetService meteorologist Kyle Lee said they received reports of tornadoes in northern parts of the Waikato and southern parts of Auckland overnight.
"There was a lot of attention around the front [weather system] that went across the North Island yesterday evening - plenty of lightning strikes along the front and pretty strong winds experienced from much of the top end of the North Island.
"It looks like there was some significant damage to a few houses and very possible we would've got a tornado or funnel cloud reaching the ground there for a brief period."
That front has since gone over and past the North Island and things are much quieter now, he said.
"We've only had a few showers for much of the western parts of the North Island and the story for today is basically the South Island should see an easing trend in the weather."
Severe weather warnings and forecast
The MetService still has severe weather warnings in place, however.
Further rain is forecast for parts of the North Island.
"A strong, most northwest flow continues to bring rain and thunderstorms to much of the North Island today.
"A watch for heavy rain remains in place for central parts of the North Island,'' it said.
An earlier heavy rain warning for the Tararua Range has been lifted this morning.
People are advised to stay up-to-date with weather forecasts as a result.
Aucklanders can expect a few showers this morning. These will become more frequent from this afternoon and there is a possibility of squally thunderstorms and hail.
Northwesterly winds are also on the cards and will be stronger in exposed parts of the city. A high of 16C is forecast and an overnight low of 10C.
Northland to Kāpiti - including the Coromandel, Bay of Plenty and the central high country - can expect periods of rain or showers today; some heavy with squally thunderstorms and hail.
Those in Gisborne and Hawke's Bay and expect fine weather. Gisborne has a high of 17C and overnight low of 8C.
In Wairarapa, Wellington, Marlborough and Nelson, a few showers are forecast this morning and rain this afternoon. Those in Wellington are in for a 12C high and overnight low of 6C.
There will also be a few showers in Buller and Westland; clearing from the south.
It will be mostly fine in Canterbury and eastern Otago and cloudy periods - with the odd shower - are forecast for the remainder of Otago and also in Southland and Fiordland.
Anyone in the Chatham Islands can expect a cloudy day with a few showers.