Main roads in the central North Island have reopened after being closed because of snow but the New Zealand Transport Agency warns the Desert Road may close again.
The Desert Road (State Highway 1) between Rangipo and Waiouru and the alternative SH4 have reopened.
The Rimutaka Hill Road (SH2) between Wellington and Wairarapa also reopened at 8am on Wednesday after being closed because of ice.
NZTA central region operations manager Mark Owen says evening and overnight frosts could mean roads on the Central Plateau will close again.
Mr Owen warns motorists to be wary of ice and take extreme care.
MetService said light snow showers from Wairarapa to National Park would ease on Wednesday and temperatures would slowly rise.
Overnight on Tuesday, hundreds of homes west and north of Auckland were without power because of heavy rain and wind, but lines company Vector said most were reconnected by morning.
In the South Island, all state highways are open, including SH 87 which was blocked by heavy snow on Tuesday, NZTA said.
All Dunedin roads have reopened after Tuesday's snow storm. Six high roads in the city including Three Mile Hill and Mount Cargill roads were blocked by heavy snow about 10cm deep for about a day.
Queenstown, Dunedin and Christchurch airports are operating normally.