Thunder, giant hail and heavy rain is expected to pummel the tip of the country for the next two days as a warning is issued for northern New Zealand.
The next 36 hours are going to be some of the wettest and wildest weather the north has had this winter with up to 120mm of rain expected to fall on Northland, northern Auckland and Great Barrier Island and hail big enough to damage crops and light structures.
Coromandel is set to be drenched with a whopping 160 mm of rain expected to fall in from 6pm until midnight tomorrow.
MetService said some severe thunderstorms would sweep across the north as continuous bands of rain started to fan over regions today. In some areas up to 40mm of rain was expected as well as large hail measuring 20mm in diameter.
MetService warned the hail was expected to be so big crops and light-weight structures could end up damaged.
There was also likely to be flash flooding.
Further south melting snow is now turning to ice on the Napier-Taupo highway as frigid temperatures continue to cause havoc on the North Island roads.
Temperatures dipped below zero overnight across both islands as New Zealand continued to shiver through its coldest spell this winter.
National Park village had the coldest night in the North Island on -4.1C, Hamilton dropped to -1.5C, Levin -1.1C and Rotorua -1C. Auckland was a chilly 4C.
MetService forecaster Derek Holland said most of the South Island recorded a sub-zero night, and Mt Cook Village dropped to -5.8C, Reefton to -5.3C and Blenheim -4.1C.
The day had started with a heavy frost in all regions.
Just one state highway remains closed but ice continues to make roads treacherous in central regions of the North Island.
The Napier-Taupo highway reopened at 11.30am after being closed for five days.
Hastings District Council said the Napier-Taupo Rd was now affected by melting snow turning to ice as temperatures stayed below zero.
The Waikato Civil Defence advised motorists travelling through the Karangahake Gorge this morning to be wary of ice.
The Waimana Gorge between Awakeri and Opotiki remained closed after a large slip blocked the road early yesterday.