Motorists may encounter snow on alpine passes as a wintry blast hits the country.
MetService says cold air is forecast to bring snow down to about 500 metres across Southland and southern parts of Otago during Saturday.
"Strong gusty cold west to southwest flow, with a series of embedded fronts, are forecast to affect New Zealand through to Monday, then start to gradually ease on Tuesday," MetService said.
"However, snowfall is not expected to meet warning criteria at this stage, but could affect higher roads and passes and also cause stress to livestock across parts of the South Island."
It marked the first snowstorm of the season for the Southern Alps.
More than 1.5 metres of snow has fallen at Aoraki Mt Cook since Tuesday.
Avalanche Advisory issues warnings for alpine and high alpine areas
The Avalanche Advisory has issued warnings for dangerous conditions in alpine and high alpine areas of the national park, and a moderate danger alert for subalpine areas.
The advisory said snow was expected to fall above 1000 metres with winds forecast to increase to severe gale.
The popular Mueller Hut route reaches 1800 metres.
It said anyone planning to head into avalanche terrain would need advanced safety skills and very careful route-finding.
"The wind direction will shift to the southwest over the weekend and wind speeds are forecast to increase to severe gale again.
"The risk of wind slab avalanches will increase."
The advisory also recommended anyone heading above the snowline to take an ice axe and crampons.
Severe gales were also possible for parts of the country this weekend.
Sub-zero temperatures for some South Islanders this morning
Some South Islanders woke to below-zero temperatures in the winter blast hitting the country.
MetService meteorologist Dan Corrigan said we have reached peak coldness in the current weather system.
"What we can see in the satellite imagery is this really cold air mass full of shower clouds with breaks in between that's sweeping across the country in a westerly to south-westerly wind flow and that's brought snow to relatively low levels in the South Island and on the Desert Road yesterday and overnight and it's really brought the temperatures down in a few places."
Lake Tekapo dropped below -4C this morning and Wanaka was around 0C for most of the morning.
Corrigan said people should check for weather warnings as there are several wind watches in place throughout the country.
Snow fell down to 200m in some parts of the South Island and South Otago farmer Bobbi Brown said the snow has settled on some of the hills.
She said it has made work a bit more challenging, especially drying off cows.
MetService issues strong wind watches
In the North Island, Metservice has issued strong wind watches for Coromandel Peninsula, Bay of Plenty west of Te Puke, Taupo, and Taihape about and east of Waiouru, Tararua District, and Hawke's Bay.
All watches were in place until Sunday morning.
In the South Island, winds might approach severe gale in exposed places in Tasman north of Belgrove, Dunedin, and North Otago until Sunday morning.
MetService said southwest winds might reach severe gale for Coastal Southland including Stewart Island and Clutha, but they should lessen this evening.