The New Zealand Fire and Emergency services responded to about 20 callouts all around Auckland and down to southern parts of the Waikato when thunder, lightning and heavy rains suddenly hit from about 8pm.
In downtown Auckland, half of The Cloud has come off and has been left in tatters.
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.
One of the buildings badly damaged was a pre-school on Bermuda Rd.
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.
Photos and videos captured by members of the public from different parts of Auckland show trees and homes damaged and debris littering the streets.
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
The MetService still has a number of severe weather warnings in place.
Further heavy rain and squally northwest winds are forecast for parts of central and northern New Zealand, it said.
"A broad trough continues to move eastwards across central New Zealand.
"On its northern flank, a moist northwest flow continues to bring rain and squally thunderstorms to many central and northern areas, and Warnings and Watches remains in place."
People are advised to stay up-to-date with weather forecasts as a result.
