LATEST: Hundreds of people face another freezing night without power as a polar blast continues to grip the country with more heavy snow due overnight.
The severe weather has also prompted police to close roads around the Wellington region, stranding many commuters.
Road closures include the Rimutaka Hill Road, Wainuiomata Hill Road, Paekakariki Hill Road, State Highway 58 (Haywards) between State Highway 2 to Moonshine Road and Blue Mountains Road in Upper Hutt.
Some Wellington and Christchurch residents were unable to leave their houses earlier today as the roads were too unsafe to drive on, and public transport was severely hit.
Travellers were stranded at airports as some flights were cancelled, particularly in Christchurch, Queenstown and Wellington where the airports were closed for part of the day.
All airports were now reopened, but warned travel could again be disrupted due to the weather.
In Wellington, more than 20 flights have either been cancelled or delayed after the airport closed its runway for nearly two hours this evening.
At 8pm, about 140 Orion customers were without power in Leeston, Tai Tapu and Dunsandel and around Christchurch city.
Power was also out to 50 homes outside Wellington and about 300 homes in South Taranaki, Whanganui, Manawatu and Wairarapa.
Residents in the lower North Island have been warned that more power cuts are expected.
A further 15 to 30 centimetres of snow was forecast to fall above 400 metres near Wellington until midnight tonight, and severe winds were expected to lash coastal areas between Canterbury, Wellington and Wairarapa.
Snow again fell in the northern hill suburbs of Wellington and in parts of the Hutt Valley early this evening. The heaviest snow was forecast for Canterbury with 15-30cm at lower levels and 30-60cm above 300 metres.
But while more heavy snow was expected this evening, forecasters say the end is in sight.
MetService spokesman Bob McDavitt said the icy southerly was expected to strengthen again, before gradually easing from tomorrow evening.
"While more snow is likely, the end is in sight. It's still a few days away though."
SNOW IN WINTERLESS NORTH
The snow that has blanketed the country since Sunday has hit parts of the country usually immune from winter including Mount Tutamoe, just north of Dargaville, which was dusted with snow this morning.
Tramper Viv Trounson said the snow on the summit was two inches thick when he made an early morning trek. He was about 580m up the mount when it started and he said snow fell steadily for around an hour.
"The snowflakes were as big as 20c pieces," he said. " It was absolutely wonderful, it was beautiful."
Jaime Melanson, who lives in Mahuta Gap just south of Dargaville, said the snow was accompanied by wind gusts of 111kmh at 8am.
Climate scientist Georgina Griffiths, of the National Institute of Water and Atmospheric Research (NIWA), said yesterday was the coldest day in Auckland since records began in 1961.
The temperature at the airport reached 8.1 degrees Celsius - compared with the previous lowest high of 8.7C, on July 4, 1996.
While at the Wellington Airport the temperature got to 6.8C making it the second coldest day there since records began in 1959, the first being 6.5C on June 21, 1976.
NIWA also confirmed a large number of record low August maximum temperatures yesterday, particularly in North Island locations.
At Tauranga's airport, the mercury fell to 8.9C - its lowest since 1941. Temperatures dropped to 3.5C in Martinborough - the lowest in August since 1986 and in Waiouru the mercury fell to -1.0C, the lowest since 1972.
In Palmerston North temperatures fell to 6.2C - the lowest August temperature since 1940, and in Hamilton, the mercury dropped to 6.8C, the second coldest day in August since 1940. Gisborne also recorded its second lowest temperature since 1940 at 8.2C.
But New Zealanders had good news to look forward to - MetService said the temperature would creep up by about one degree each day until the end of the week.
Many state highways around New Zealand were closed, including the Desert Road and Rimutaka Hill road in the North Island and the Lewis Pass and Arthurs Pass in the South Island.
Police have warned of treacherous driving conditions as the snow would turn to ice, which has already seen one car slide off the road on the southbound lane near the Tawa off ramp this morning.
Prime Minister John Key called on employers to be compassionate to workers who were snowed in, and said the timing of the weather was "slightly lucky" as farmers were just beginning lambing season.
"If there is a whole lot of snow and ice and you can't get out of your driveway then you'd expect employers to take a generous view towards that," Key said.
Conditions in the northern hill suburbs of Wellington remained hazardous with 24 hours of snow now frozen on the ground.
The Transport Agency was liaising with police to get the slush swept off roads, and grit poured over the worst-hit places to give more traction.
These include the Ngauranga Gorge, State Highway One near Otaki, Levin and Manakau, and State Highway 56 near the Longburn overbridge where numerous cars were reported to have slid off the road.
Mail was not delivered for a second day in some parts of the country with the entire lower North Island missing a postal delivery today.
Many children stayed at home as some school in Wellington and all schools in Christchurch were closed. And bus services were disrupted in both cities.
- Stuff, Dargaville News, The Dominion Post, The Press, Southland Times and Taranaki Daily News