Thousands of frustrated Aucklanders are waking to their third day without power after another bout of wild weather overnight and more heavy rain set to hit tonight.

Some rest-home residents have been left shivering in the dark, a couple with a son suffering from leukaemia are frustrated at delays restoring electricity, and trees have crashed through enclosures at the zoo.

There was a slight reprieve from the cold weather overnight, with warmer temperatures for the thousands of Aucklanders still without power.

Contractors are making ground in their massive repair job: Vector said this morning the number of properties without power in the Auckland area was down to 17,000, from 22,500 last night.

MetService meteorologist Stephen Glassey said there were some strong winds in Auckland last night, but nowhere near as strong as during Tuesday's storm.

The top wind gust last night was 135km/h at the exposed Manukau Heads station, while Auckland Airport recorded a top gust of 70km/h.

A tornado struck Taranaki earlier last night, which shocked residents said sounded like a roaring freight train.

Sandra Whitmore of Waiwaka Terrace in New Plymouth said the "mini tornado" passed through her neighbourhood at 6.50pm.

"There was 20 seconds of heavy rain pelting down, it drowned out the television, there was a slight pause then there was a gust of wind and there was a roar.

"It sounded like a freight train and was over in 10 to 15 seconds."

When the storm passed and her family looked outside the thud was the next-door-neighbour's trampoline which had been anchored down but blew over to their deck.

Taranaki Civil Defence group controller Craig Campbell-Smart said there had been reports of damage but no reports of injuries.

"We have reports of localised damage to a broken house window, one fence down, trees down on a local intersection and a door being blown open."

There was widespread rain last night through the North Island, but it came in a short, but heavy, burst.

The highest recorded rainfall over a 12-hour period was 14mm on Mt Taranaki.

The coldest areas overnight were in the deep south, with Manapouri on -3.4C and Tekapo -1.7C.

Auckland was sitting at 15C about 5am this morning, far warmer than Wednesday morning which got down to 7C.

Tuesday's ferocious storm knocked out power to 180,000 homes, uprooting trees and downing power lines.

Vector employees worked desperately yesterday to reconnect customers but more than 25,000 remained in the dark last night, with many people angry at the delays as temperatures plunged this week.

A relative of an elderly patient at St Margaret's Hospital and Rest Home in Te Atatu was outraged after patients were allegedly left cold and in the dark for nearly two days with nurses working by torchlight.

The patient's son was shocked when he arrived on Wednesday to check on his mother, walking in to find patients sitting there feeling cold and nurses having to work in what he described as unsafe conditions.

"I went to see my mum and couldn't believe it. There was no power. It was all dark," the family member said.

"The poor staff have to work by torchlight and that's not safe either. There is no heating in the place and it's cold inside."

CHT St Margaret's Hospital chief executive Max Robins told the Herald that while the disruption wasn't ideal, patients were provided warm clothing, bedding and extra care during the power outage.

"Throughout the entire time without power, hot food and drinks, warm clothing and bedding, and extra care from our dedicated staff ensured that resident welfare was never compromised.

"Staff worked tirelessly to meet the needs of residents, remaining calm, focused and using emergency headlamps and torches to do their job to the best of their ability."

One Auckland couple said they felt "let down" by poor communication about when power would be restored while they cared for their young son, who has Acute Lymphoblastic Leukaemia (ALL).

Glenn Watts and Kloe Cox have been without power at their Titirangi house since 9pm on Tuesday.

Their son Mason, who is almost 2, was diagnosed with leukaemia in February and is now neutropenic, which means he has a low white blood cell count which makes him vulnerable to infection.

Watts said his son's ability to fight bugs was minimal - "even taking him to hospital is a risk".

The family spent a full day at the hospital on Wednesday and after checking Vector notices they returned home that night thinking the power would be restored.

A Vector phone message had said the power would be back on at 7.30pm on Wednesday - however, later the day the mobile app updated and said the power would not be restored until 6pm yesterday.

The family spent a miserable night at home in the cold, returning to hospital yesterday for chemotherapy.

Auckland Zoo was also hammered by Tuesday's storm, with a large gum tree toppling down into the Pridelands enclosure that is home to giraffes, zebras and ostriches.

Acting director Kevin Buley said in his past eight years at the zoo he had never such damage from a single weather event.

"Coming in and seeing the damage is one thing but knowing all the animals are fine and no one was injured is the most important thing," he said.

All potentially dangerous animals had been confined before the rough weather hit, he said.

The multitude of issues seen across the city followed a night of weather mayhem on Tuesday that blasted Auckland with gale force winds with gusts peaking at 212km/h at Manukau Heads.

The wind tore roofs from houses and uprooted trees that came crashing down on more than 100 power lines across the region. At its peak 180,000 homes were without power.

Vector's outage field staff are working through the list of more than 690 faults, power outages, and reports of damage on the network, but warn Aucklanders it could be days till all remaining customers are reconnected.

The weather was on an easing trend through the day, with just some scattered showers, Glassey said.

"Southwest winds are easing through the day, but another system is expected to bring some rain to the upper and central North Island from this afternoon," Glassey said.

"From this afternoon and evening there could be heavy falls in Waikato, Coromandel and Auckland to tomorrow morning."

A ridge moves over the South Island and lower North Island on Saturday, while a front moves south over the upper North Island.

On Sunday rain will spread into the South Island as the front arrives.

Next week is looking pretty "changeable", Glassey said.

From Sunday through Tuesday, a series of fronts pass over the country from the west, with west to northwesterlies strengthening over the country on Monday.

"There is going to be some severe weather with those features, so my message is to expect changeable conditions."

There is a moderate chance rainfall may reach warning levels about Fiordland and Westland over this period, in Buller on Monday and Tuesday, and the Tararua Range on Monday.

There is a lower chance of warning level rain in Taranaki, the central North Island high country and eastern Bay of Plenty Ranges on Monday.

On Monday there is also a low chance of severe gale northwesterlies for a time about Fiordland and Southland, and of severe gale westerlies about northern Wairarapa and central Hawkes Bay.