Auckland Harbour Bridge motorists have been warned to take care with big winds set to hit the city while avalanche warnings have been issued across both islands with forecasts of heavy snowfall.
Southwest winds could reach severe gale in exposed places of Auckland - where a warning is in place until Monday morning.
Waka Kotahi NZ Transport Agency asked motorists to take extra care if they were travelling over the harbour bridge - especially those in high-sided vehicles.
Wind warnings had been issued for parts of Northland, south of Dargaville, Great Barrier Island, Coromandel Peninsula, Wairarapa, Wellington, Hawke's Bay, Gisborne, Taranaki, Whanganui, Nelson, Buller, Westland and Kaikoura Coast.
Heavy snowfall prompts warning
As winds lash some parts of Aotearoa, residents in other areas have been told to brace for heavy snowfall - prompting the NZ Mountain Safety Council (MSC) to issue high avalanche warnings.
The "largest snowfall event" of the winter was set to produce significant amounts of new snow for many eastern South Island alpine regions - and for the central North Island, as the system moved north, the MSC said.
The heaviest snow was expected in parts of northern Canterbury and southern Marlborough above 200m, and central and southern parts of the North Island.
State Highway 73 from Arthur's Pass to Ōtira is closed due to snow.
Avalanche danger ratings had increased to "high" for Aoraki/Mt Cook, Two Thumbs, the Craigieburn Range, Nelson Lakes and Tongariro, and to "considerable" for Arthur's Pass, Mt Hutt, Taranaki and Ohau.
MSC chief executive Mike Daisley urged backcountry users to give the new snow time to settle before heading out to enjoy it.
"The 24-48 hour period after a storm like this one is the most dangerous and while the temptation is to rush out and get the fresh powder, it's really the time for patience and a cautious approach," he said.
"The first fine, clear day following this system is likely to produce numerous loose wet avalanches as the snow warms up from being exposed to the sun."
The snow was likely to disrupt travel, damage trees and powerlines, and cause stress to livestock.
Snow is falling on a number of alpine passes and more was on the way, possibly to as low as sea level in some parts.
It was sleeting and trying to snow on Christchurch's Port Hills at about 12pm.
Snow was blanketing the Crown Range, the Porters, Lewis and Burkes passes and was reportedly falling across most of Canterbury above 200-300m.
A heavy snow warning has been issued for Taihape (from 11pm), the Tararua and Remutaka ranges (from 8pm) and Marlborough south of Seddon and Canterbury north of the Rakaia River (until 9pm).