A tornado has ripped through a pā near Hokitika, destroying a kohanga reo building, and lightning has caused damage in the upper North Island.
The tornado hit about 5.30am at the Ngāti Waewae pā at Awatuna, ripping the roof off the small blockwork building.
The iwi's chairman, Francois Tumahai, said he was sad to see the building destroyed but relieved nobody was hurt.
"If it had've been 20m one way or the other, it would have taken out ... four kaumatua homes. It would have been quite devastating."
The kaumatua, who heard the tornado coming up the valley from the sea, were all fine and helping to organise the clean-up, he said.
The building was unlikely to be able to be repaired, he said
"Where the windows and the doors are, they've been ripped out. The roof has been torn off and thrown up onto the railway tracks about 200m away... there's gib board everywhere. It's just a mess," he said
The last kohanga pupils left last year so it was not currently in use.
The tornado also took out warning bells at a railway crossing near the corner of State Highway 6 and Old Christchurch Road, north of Hokitika, with a witness telling police it sounded like a car crash.
Flooding in North Island as lightning strikes homes, DOC hut
Thunderstorms swept across the Waikato coast and Auckland early this morning, bringing heavy rain and damaging lightning to some areas.
The Te Kuiti Volunteer Fire Brigade said it had rescued people stuck in a car in flooding at Tumutumu Road, near Waitomo. It estimated 45mm had fallen over three to four hours overnight.
A fire at a Department of Conservation hut in the Pureora Forest Park is believed to have been sparked by lightning strikes, which also damaged three houses south of Auckland.
Benneydale chief fire officer Murray Paterson said his team battled a howling gale, pouring rain and flooding on the road to reach the hut. When they arrived, it was about 80 percent ablaze, he said.
It looked like lightning had hit a transformer next to the building, he said.
Fire crews were called to three houses on Kohekohe-Karioitahi Road in Pollok, north of Waiuku, about 5.30am. The lightning there damaged a roof and caused lights and electrical sockets to smoke.
Fire shift manager Paul Radden said the electricity had removed tiles from one of the houses, causing a water leak.
He told Morning Report crews replaced the tiles, and checked that the power outlets and light fixtures in the other houses were safe.
At least 30 lightning strikes in Auckland region
MetService severe weather forecaster John Crouch told Morning Report lightning could start a house fire if it penetrated a roof into an attic and ignited insulation, or if the electricity ran through internal plumbing or wiring and set walls on fire.
He said the bands of lightning would have produced several thousand lightning strikes as they moved across the Tasman Sea.
The storms would have weakened slightly when they hit the cooler land, but there were still more than 30 recorded strikes in the Auckland region.
"Lightning tends to hit higher objects - Sky Tower gets hit quite a lot in Auckland - but it can hit houses that are higher up, perhaps on the top of hills."
Mr Crouch said it was best to stay inside in a lightning storm, and take precautions such as not using a phone landline connected to the network.
"What you do want to do is stay away from anything metallic - so don't touch taps, they can conduct electricity.
"Having a shower can be a bit dangerous as well - often it pays if there is lightning around not to have a shower."
Power surges were the main risk, so the advice was to unplug appliances such as computers or TVs, especially if they didn't have surge protectors.
Mr Crouch said the north-westerly flow bringing the storms would strengthen today and stay around over the weekend, and there would be more thunderstorms on western areas of the North and South islands.