• Snowfall warnings across the country
• Motorists urged to take care with snow warnings for Desert Rd, Napier-Taupo Rd and Rimutaka Hill Rd
• South Island roads impacted include the Lindis, Lewis, Porters, Arthur's Passes and the highway between Dunedin to Waitati
• Sub-zero temperatures expected for South Island
• Schools closed in Dunedin
The bitter cold snap is set to smash a weather record that has stood for more than a century as an icy chill takes hold of the South Island.
Temperatures are set to plunge to a frigid minus 15C across the South Island tonight - but it's expected to be even colder overnight Saturday.
Philip Wallace captured this footage showing snow falling in Wellington at the Rimutaka summit.
Niwa forecaster Ben Noll said forecasters were keeping a close eye on Queenstown where it could reach one of the coldest temperatures since record keeping began 145 years ago.
"The coldest temperature for August is -7.8C and I can tell you they will be in the neighbourhood of that number," he said.
The coldest temperature ever recorded in the popular resort town was -12.2C in 1995.
Noll said many southern centres now blanketed in snow could be in for an exceptionally cold night with the snow acting as a refrigerant, lowering the forecast temperature.
He said it was shaping up to be the coldest weekend of the winter.
New Zealand's coldest temperature was -25.6°C recorded in Ranfurly in July 1903.
Snow has started falling in the North Island as the big chill heads north.
MetService has issued a swathe of fresh road snowfall warnings across the country with snow falling on the main route connecting Wellington with the Wairarapa.
As much as 6cm of snow would fall on the summit highway, mostly this afternoon.
A further 1-2cm dusting was likely early Saturday.
Other roads impacted by the coming blizzard include the Desert Rd where up to 15 cm of snow was expected from this afternoon until early Sunday.
The Napier-Taupo Rd was also expected to be affected by snowfall this evening with up to 60cm falling above 400 m from this evening until Sunday and lesser amounts down to 200 m.
A number of highways across the South Island were also impacted by snow including the Lindis, Lewis, Porters, Arthur's Passes and the highway between Dunedin to Waitati.
The Lewis and Porters passes would be the worst affected with up to 25 cm of snow falling between now and Saturday night.
MetService is warning Hawke's Bay across to Taihape could expect significant snow down to low levels tomorrow morning.
The heaviest snow is likely to fall about inland Hawke's Bay and eastern Taihape from tonight through to early Sunday morning.
Up to 50cm of snow was expected to fall above 400 metres, with 1 metre snow drifts.
Blizzard conditions were likely in exposed areas of the North Island.
The MetService also issued a watch for the possibility of heavy snow about southern parts of Gisborne and the Tararua District.
It said significant snow could fall above 400m from tonight through to Sunday.
Heavy snow was expected to cause major disruption to transport as well as significant stress to livestock, and damage powerlines.
On the brink of one of the coldest weekend's of the year, with temperatures set to drop to a bone-chilling -11C the MetService is now forecasting "a fairly signficant" amount of snow down to low levels across the eastern region.
The MetService is warning the wintry blast will bring sub-zero temperatures to the South Island on Saturday night and low single-digit temperatures across the North Island.
Forecasters said heavy rain forecast for Hawke's Bay was now likely to turn to snow due to the cold air. He said it was likely to disrupt travel on the Napier-Taupo Highway and Desert Rd.
Snow is expected to fall in Canterbury today from Banks Peninsula south with light flurries down to sea level. It's currently snowing in Timaru with snow showers expected throughout the morning. Snow fell overnight on Dunedin and Otago, but forecasters said the worst of the weather was shifting north leaving bitterly cold temperatures in its wake.
Alexandra is expected to drop to -11C and Ashburton to -6C.
The snow in Dunedin has closed several schoolsand Dunedin's Northern Motorway. Bus services are also affected as snow and ice settle around the city this morning.
The following schools are closed for the day: Otago Girls' High, King's High, Queen's High, Taieri College, Kaikorai Valley College, East Otago High, Dunedin North Intermediate, John McGlashan College, St Mary's Kaikorai School, Waitati Primary, Palmerston Primary and Flag Swamp School.
All other primary and intermediate schools and kindergartens from Mosgiel to Port Chalmers to Waikouaiti will start at at 10am.
Several high schools are also starting at 10am, including: Bayfield, Logan Park, John McGlashan, St Hilda's, Otago Boys'.
Columba and Kavanagh will start at 11am.
The Otago Regional Council advises that all bus services in the city's hill suburbs are suspended. Opoho and Pine Hill services are currently terminating at the Gardens, the Shiel Hill service at Bayfield, and the Concord service at the Octagon.
Most roads are open; however, the Northern Motorway, Mt Cargill and Three Mile Hill are closed owing to ice and snow.
State Higway 1 Palmerston-Waitati and SH87 Outram-Middlemarch are both closed to towing vehicles, while a slip has closed one lane of SH8 in the Manuka Gorge.
Flights at Dunedin Airport are currently running to schedule.
The disruption comes despite MetService having downgraded its warning for heavy snow in Dunedin and North Otago over the next few days.
MetService communications meteorologist Lisa Murray said the forecast warnings for heavy snow in Dunedin and North Otago had been lifted, because the "low" moving across the North Island was further north than expected.
As a result of the weather warnings, most rugby games in the city have been cancelled for this weekend.
Metservice forecaster Angus Hines warned the freezing conditions could spell danger for motorists across the island.
"Travellers will need to take extra care this weekend. The overnight temperatures will freeze any surface water, which can result in dangerous black ice on the roads."
The weather system that bought snow to the south is expected to bring rain to extensive areas of the North Island in coming days. A severe weather watch for heavy rain has been issued for Gisborne and Hawke's Bay until tomorrow.
North Islanders would also feel a sting in the air as the southerly wind extended up the country.
Wellington would be right in the firing line for the big Super Rugby final on Saturday evening, when temperatures are expected to hover around 5C during the game and a wind chill fact will make it feel even colder.
Auckland was looking at a maximum temperature of 12C across the whole weekend.
Here's Philip Duncan's WeatherWatch:
- Additional reporting: Otago Daily Times