A snow plough is on its way to rescue cars stuck in snow on the Desert Road through the centre of the North Island.
NZTA advised of the closure in a tweet shortly before 5pm on Saturday. The road from Rangipo to Waiouru is part of State Highway 1.
Police said several vehicles are reported to be stuck in the snowy conditions.
There are no concerns for safety at this stage.
Images of snow falling on Saturday at the Turoa and Whakapapa ski areas in the centre of the North Island were also posted on Facebook, with the operator saying snow had also fallen briefly in the nearby township of Ohakune.
A strong, cold southwesterly flow covered New Zealand on Saturday, with snow falling to low levels in the far south, MetService said.
Dunedin, Central Otago and Queenstown were among areas to receive snow overnight on Friday, and MetService issued a heavy snow warning for continued falls on Saturday.
It said during this time snow could continue to fall to low levels in the Southern Lakes, Dunedin, Southland and Clutha.
In the South Island, SH87 from Sutton to Outram is closed due to snow.
"If you're heading up the Coronet Peak Road please carry chains, tonight is not a good night to get stuck," Queenstown Lakes District Council tweeted.