FIVE THINGS YOU NEED TO KNOW:
* Power is still out to 28,000 homes in Wellington. Wellington Electricity is working to restore supplies.
* Multiple Wellington schools have been closed for the day as a result of power outages.
* Flights, trains, ferry and bus services are being disrupted nationwide, and several roads are closed around the country.
* A lightning strike in Stanmore Bay, Auckland shattered a tree and damaged a dozen homes.
* The polar blast is set to continue today but should ease this evening.
* Send your weather related stories, photos or video here.
* Read our live weather updates blog here.
Council workers have started cleaning up the mess left by what's been described as the worst storm to have hit Wellington in decades.
Wellington region Civil Defence controller Bruce Pepperell said the council and utilities were working hard to get things back to normal as the wind died down.
"I know that big efforts are under way to get power back on to more than 25,000 customers around the region and that work to restore the rail commuter network is also under way,'' he said.
Middleton Rd in Johnsonville and the road access to Makara, where several large trees came down overnight, were considered priorities.
Work was also starting to clean up the seaside roads on Wellington's south coast, particularly the Esplanade between Island Bay and Owhiro Bay, which was severely damaged by huge waves.
The stretch of road was expected to be closed for at least another 24 hours and it could be weeks before it was fully repaired.
Petone resident Heather Patel thought her house was going to come down in the strong winds that have been hammering the seaside town today.
Her house was okay, but about 8am her garage came crashing down.
"A big gust of wind lifted the whole (garage) roof,'' she said.
Fortunately the car wasn't parked inside, but only because the ferocious winds last night stopped her from being able to open the garage door.
"But there was a motorbike in there that's now totalled.''
More than 150 schools closed today due to the wild weather battering the country.
Ministry of Education deputy secretary regional operations Katrina Casey said 71 schools had closed in the Canterbury region and a number of others were considering following suit.
In Wellington, 58 schools were closed today and in greater Dunedin, Southland and Central Otago 30 schools were shut.
Numerous other schools had started late and some may close early should the weather deteriorate further.
The ministry had also received reports of damage to some schools.
"We will work closely with the school to make sure any damage is promptly repaired,'' Ms Casey said.
Wellington Airport has reopened after being shut due to the worst storm in the capital in years.
A spokeswoman said it had now been deemed safe for planes to land and take off.
It was up to individual airlines to determine whether or not to resume operating.
Air New Zealand said its flights in and out of Wellington were suspended until noon and the situation remained under review.
Its jet services continued to operate in Christchurch, however some regional link services had been cancelled.
In Dunedin, all Air New Zealand operations were suspended.
Its Queenstown jet services continued to operate, however, Mt Cook services into and out of Queenstown had been cancelled until 11.30am.
Elsewhere there were delays across Air NZ's network due to weather conditions across the country.
Passengers whose travel plans have been disrupted can call the airline's contact centre on 0800 737 000.
The storm has caused extensive damage in Wellington, with ripped up roads, toppled trees, damaged houses, crippled public transport and power cut to some 28,000 customers.
Massive seas on the city's south coast have damaged a sea wall at Island Bay in multiple places.
The damage happened about 2.30am, the council's manager of city operations Zac Jordan said.
The damage was being assessed by GeoScience workers this morning.
The surface of a carpark further along the Esplanade had also been ripped up, he said.
The council's first priority was ensuring trees were away from power lines and public safety was ensured.
Local resident Andrwa Jordan woke to find two surfboards at her front door.
"I've never seen it this bad," she said.
Huge waves are crashing into shore and boats are being knocked about, but so far none have been pulled from their moorings.
Winds gusts reached 140km/h in the capital overnight and 200km/h on Mt Kaukau near Khandallah, while sea swells in the Cook Strait rose to at least 10m.
Contributing to numerous comparisons to the 1968 storm which sank the Wahine, an interislander ferry was pulled from its moorings in Wellington Harbour overnight.
Many schools in the region were forced to close for the day as a result of the widespread power outages.
Lines company Wellington Electricity said some 28,000 customers were this morning without power, down from about 35,000 last night.
Wellington region Civil Defence controller Bruce Pepperell said conditions had this morning eased sufficiently for repair work to begin, but there was a significant backlog due to the volume of jobs.
Fortunately, no-one had been killed or seriously hurt in the storm but there had been widespread property damage, although the extent was not yet clear.
"A lot of sections of roof have blown off, carports have collapsed and we've got a trampoline on a roof," Mr Pepperell said.
Wellington's main highways had reopened but the rail network was nearly crippled and there were significant delays on public buses.
However, traffic was moving, albeit very slowly.
Police reiterated the need for extreme care while driving because there was no guarantee all road blockages and power line issues had been attended to or clearly marked.
Possibly the hardest-hit areas were on Wellington's south coast, where large boulders were pushed onto seaside roads, ripping into the tarmac.
A Wellington Council spokesman said the Island Bay seawall was "coming down" from being pounded by unrelenting waves.
Wellington Mayor Celia Wade-Brown praised the workers and volunteers who toiled in treacherous conditions overnight.
"Workers have been out clearing roads and trees and getting power back on - and they have been working in truly tough and dangerous conditions. I thank them for their huge efforts overnight."
She said many people involved in the emergency response had described the winds as probably the worst since the 1968 Wahine storm.
A Fire Service central communications centre spokeswoman said they had fielded 932 emergency calls in the 12 hours to 6am.
Almost 500 had been to assist members of the public with storm damage and about 360 had been to help the council and power companies.
"We're still going flat tack," she said about 7am.
About 28,000 customers in Wellington remain without power, with lines company Wellington Electricity said strong winds and torrential rain had caused damage to the area's electricity infrastructure and the company was working to restore supply.
However, the huge work volumes could cause delays.
Affected areas included Trentham, Titahi Bay, Wingate, Wainuiomata, Miramar, Kingsley Heights, Makara, Oharu Valley, Belmont, Seaview, Petone, Newlands, Tawa, Plimmerton, Mana, Gracefield, Waterloo, Korukoru Days Bay, Naenae, Waitangirua and Porirua.
Wellington Electricity urges affected customers to:
* Stay well away from fallen powerlines.
* Listen to a portable radio for official advice and power restoration information.
* Check on neighbours, particularly the elderly.
* Be patient and spare a thought for power company crews, who are often working under harsh conditions..
The Kaitaki ferry in Wellington broke its moorings, and had to be anchored in the harbour after it was unable to be brought back into its berth, it was reported.
Karori resident Jessica Ranger said it was the worst weather she had experienced in Wellington.
"We are getting hammered by the wind. We can hear trees banging against the windows."
Snow has now stopped falling in Christchurch, leaving just a fine layer settled on parts of the city.
Latest forecasts for the city show snow easing off this morning, turning to showers and hail this afternoon.
Further snow is possible overnight and tomorrow morning.
Heavy rain is still expected over the next 24 hours making driving conditions dangerous.
Surface flooding is an issue in low-lying areas across the city, with the council asking drivers to take care.
The council also warns that earthquake-damaged wastewater systems remain fragile in parts of the city and have been blocked by rain.
"It's possible flooded roads and parks may be contaminated, so avoid the water where possible or make sure you wash your hands and remove and wash any clothing that gets wet," a city council spokesman said.
"Hill roads are currently extremely dangerous for motorists and should be avoided until later this afternoon.
"The weather will remain wet and cold over the weekend. People are asked to check in on older people or those with disabilities who live alone in their neighbourhoods."
Schools have closed, flights and buses are cancelled or delayed and motorists are urged to take extra care.
Alpine passes, Porters, Lewis, and Lindis Pass remain closed this morning, while chains are essential over the main east-west road, Arthurs Pass.
On the Port Hills, heavy snowfall has forced the closure of Dyers Pass Rd, from the Sign of the Takahe to Governors Bay Rd. Council teams are assisting motorists stuck on the route and clearing the snow.
Motorists have been urged to slow down and drive with care, especially in areas affected by flooding earlier this week.
"The wakes and waves caused by vehicles can cause further flooding to already at-risk properties," a council spokesman said.
Environment Canterbury Regional Council has cancelled bus services whose routes take in hills and warned of delays.
St John has reported no major incidents in the South Island overnight.
The Desert Road is likely to be affected by snow until at least tomorrow morning, but a Fire Service spokesman said there had only been a couple of weather-related calls in the country's north today.
In Auckland, trees were toppled, homes damaged and at least two people hurt as a wild lightning, thunder and hailstorm hit the city last night.
At Stanmore Bay, north of Auckland, 12 houses were damaged and windows blown out by trees hit by lightning at 10pm. One person was treated for chest pains.
Fire Shift Manager, Scott Osmand, said the strike blew out windows in a dozen nearby houses.
He said a couple of houses had parts of a tree fall on them and there was a bit more damage but it was mainly minor.
A man was taken to hospital from Point England with a leg injury after lightning struck a tree which then fell onto his house.
Auckland fire-fighters were also having to handle an overflow of calls from their flat-out Wellington colleagues.
Another person is believed to have suffered minor leg injuries after lightning hit a Norfolk pine in Pt England. It is understood the tree fell on at least two homes, scattering debris for up to 400m and cutting power to the street.
Pilkington Rd, Pt England resident David Gahaafe said he was watching TV about 9.50pm when bark flew through his lounge window.
"There was an almighty crash like a missile coming through the window. Luckily the drape covered the window. The force of it was huge."
The bark had been blasted off the tree from 30m away.
Swanson resident Jade Dobson said the hail was so bad that a boarder in her downstairs flat couldn't get the door open.
"It was about 10cm high in the corner where her door is.
"The whole driveway was white, the deck was white and my husband was skating up and down the driveway."
A woman driving on the Northwestern Motorway by Brigham Creek said hail turned the ground white at 6.30pm.
"It looked like it was snowing; the whole motorway was white," said Andrea Binning, 32.
When she returned to her Sandringham home, "it was hailing so hard that it turned our driveway to ice and all the cars were covered in hail. It hasn't melted ... It's frozen on the ground".
Ms Binning said the lightning was "pretty crazy. It was every minute and it was lighting up the whole of West Auckland".
Eden Terrace resident Peter Green was on a bus when the hail struck about 9.30pm.
"All the pavements are white and the road outside is just ice."
MetService forecaster Heath Gullery said intense hail was not uncommon in winter, but was probably more visible last night because it remained on the ground for longer.
The reason for that was the colder temperatures.
Last night's hail and thunderstorms were part of a band of weather that was expected to ease this morning - making way for potentially damaging 120km/h winds.
Those winds would also be cold and would make the maximum temperature of 12 degrees seem much colder, Mr Gullery said.
- Christchurch bus services have been affected due to snowfall in hill suburbs. Metro Bus Services has updates here.
- Portobello bus services in Dunedin have been delayed due to a tree blocking Portobello Road between Broad Bay and Company Bay. Read more on the Otago Regional Council website here.
• SH1 from Rangipo to Taihape, closed due to snow
• SH46 from Rangipo to Tongariro, snow
• SH 48 Tongariro National Park, snow
• SH 47 from Turangi to National Park (SH4), snow
• SH 4 and 49 from National Park to Waiouru, snow
• Paekakariki Hill Road, slips
• SH6 from Harihari to Makarora, closed due to high winds
• SH73 from Springfield to Arthurs Pass ( Porters Pass), snow
• SH7 from Hanmer turnoff to Springs Junction ( Lewis Pass), snow
• SH85 from Omakau To Palmerston, snow
• SH8 Lindis Pass, snow
• SH79 from Geraldine to Fairlie, snow
• SH87 from Kyeburn to Outram, snow
• SH8 from Twizel to Fairlie (Burkes Pass), snow
• SH80 from Glentanner to Mt Cook, snow
• A number of Dunedin roads remain closed due to flooding, snow and slips.
• Dyers Pass Road, Christchurch, is closed from the Sign of the Takahe to Governors Bay Road, due to snow.
A number of schools are closing today due to the wild weather - see the full list here:
• All Wellington Kindergartens - closed
• Aotea College - closed
• Avalon Primary - closed
• Belmont School - closed
• Bishop Viard College, Porirua - closed
• Dyer St School - closed
• Eastern Hutt School, Lower Hutt - closed
• Epuni Primary School - closed
• Gracefield School - closed
• Greenacres Primary School, Tawa - closed
• Hampton Hill School, Tawa - closed
• Hutt Intermediate - closed
• Island Bay Kindergarten - closed
• Island Bay School - closed
• Khandallah School - closed
• Kimi Ora School NaeNae campus - closed
• Korokoro School - closed
• Mana College - closed
• Maungaraki School - closed
• Naenae Intermediate - closed
• Naenae School - closed
• Newlands Intermediate - closed
• Newlands Primary School - closed
• Onslow College - opening at 10am
• Our Lady of the Rosary School, Waiwhetu Rd - closed
• Papkowhai School - closed
• Pauatahanui School - closed
• Pukerua Bay Primary School - closed
• Rangikura School - closed
• Raphael House, Rudolf Steiner School, Lower Hutt - closed
• Rata Street School, Naenae - closed
• Rewa Rewa School - closed
• Ridgeway School - closed
• Sacred Heart, Petone - attendance optional
• San Antonio, Eastbourne - closed
• South Wellington Intermediate School - closed
• St Bernard's College, Lower Hutt - closed
• St Oran's College - closed
• Tairangi School - closed
• Tawa College - closed
• Tawa Intermediate School - closed
• Tawa School - closed
• Waterloo School - closed
• Wellesley College, Eastbourne - closed
• Wellington East Girls College - closed
• Wellington Girls College - open day is cancelled but the school will be open for anyone who can make it
• Windley School, Porirua - closed
• Addington School - closed
• Aranui High School - closed
• Cashmere Primary School - closed
• Cheviot Area School - opening at 10am
• Christchurch East School - closed
• Christchurch Rudolf Steiner School- closed
• Discovery One - closed
• Lincoln High School - closed
• Linwood Ave School - closed
• Oxford Area School - closed
• Phillipstown School- closed
• No Richies school buses running today in Oamaru and North Otago
- NZ Herald, APNZ, Newstalk ZB