Snow has begun falling in the far south and on mountain passes as a late winter cold spell arrives.
A severe weather warning remains in place for inland parts of the South Island, where more snow is forecast to fall this afternoon and overnight, as low as 200m.
State Highway 94 from Te Anau to Milford Sound, and Haast Pass (State Highway 6) on the Otago side were both closed earlier today but have both reopened.
The New Zealand Transport Agency had also lifted restrictions for towing vehicles on Lewis Pass, Porters Pass and Arthurs Pass but said cars on those roads should take extra care.
Heavy snow fell in Glenorchy, where photos showed it settling on the shores of Lake Wakatipu.
Snow was also heavy on the Crown Range between Wanaka and Queenstown.
Clutha District Council warned drivers heading over the range to use chains.
MetService duty forecaster Claire Flynn said the weather had eased slightly, but there would be further flurries this afternoon right through until tomorrow morning that would bring the snow level even lower.
A low sitting off to the west of New Zealand would bring very cold temperatures too, she said.
Overnight temperatures would drop below 0°C throughout Canterbury, Otago and Southland from tomorrow evening.
The coldest temperatures were forecast for Alexandra, where overnight lows of -5° were predicted for tomorrow, falling to -9° over the weekend.
On Sunday, the high for Alexandra was forecast to reach just -2°.
Gore, Invercargill, Wanaka, Queenstown and Timaru would all experience lows well below 0°.
Canterbury Civil Defence regional manager Neville Reilly said people should be prepared to hunker down.
"They should have supplies of food and water, an alternative method of heating if there's no electricity, like a gas heater, and an alternative method of cooking."
MetService said the heaviest snow, with about 20cm to 30cm above 400m, would fall about inland parts of Southland and Otago, with 5 to 10cm accumulating down to 200 metres.
For Canterbury south of Fairlie, 25cm to 35cm was expected above 400 metres, with 10 to 15cm possible down to 200 metres.
Blizzard-like conditions were expected in exposed areas, MetService said.
Federated Farmers Otago provincial president Phill Hunt said farmers in his area were already taking precautions.
"There are a lot of farmers who are taking heed of the advice and moving stock to more sheltered country that's less snow-prone and where they're easily accessed if there is a large fall."
It was fortunate that most Otago farmers had not started lambing yet, Mr Hunt said.
Stock feed levels had been quite low at the start of the season but until now winter had been "very kind" to farmers, he said.
"There has been a measure of grass growth ticking away the whole way through ... and stock condition coming out of the winter is pretty good."
Further north, NZTA was advising caution because of snow and ice on the Desert Road and in the Tasman region on State Highway 60 between Takaka and Riwaka.
Lines companies and regional civil defence teams said they were keeping an eye on the weather but it was business as usual so far.
PowerNet, the lines company for Southland and South Otago, had its regular crew of about 12 working but had access to up to 30 staff if they were needed, spokesman Murray Hamilton said.
In Canterbury, Orion chief executive Rob Jamieson said if heavy snow arrived as forecast, some power cuts were likely.
Staff were on standby to respond and the company would fix problems as fast as it could, but people in rural areas should be prepared to be without power for a few days, Mr Jamieson said.