An Antarctic blast is set to hit Hawke's Bay toward the end of the week, with WeatherWatch forecasting the country will receive 48 to 72 hours of wild winter weather.
Tomorrow night will signal the beginning of the cold snap for the region with the overnight low dropping to a chilly 1C.
The Friday forecast for Napier is heavy rain at times with accompanying strong cold southwesterlies, and a high of just 10C.
In Hastings, the high will reach just 9C while overnight lows for Napier and Hastings will remain just above freezing point throughout the weekend.
Further south, Dannevirke residents will brace themselves for arctic conditions on Friday as the high reaches 5C, only a few degrees warmer than the overnight low of 1C.
WeatherWatch forecast the storm will push into the North Island with damaging winds possible along eastern areas by the end of the week.
Snow may be heavy through the Central Plateau and eastern areas may be cut off to the north and south if snow closes major highways.
By tomorrow night hurricane-force southerlies will blast central New Zealand with gusts up to 150km/h from Kaikoura to Wellington and southern Wairarapa. Many areas of the country will be fully exposed to the blast directly off the Antarctic ice shelf - where temperatures were predicted to drop to near -40C overnight at Scott Base.
"This winter storm will have quite a bit of bark and bite, and is expected to bring widespread severe weather for much of New Zealand," MetService spokesman Daniel Corbett said.
Friday looks to be the coldest day nationwide, with WeatherWatch saying most areas of New Zealand would be colder at lunchtime than they were overnight.
The wind chill will be below zero for exposed parts of Wellington, Christchurch and Dunedin with wind chills in some exposed parts of the South Island dropping to -15C.
WeatherWatch advises farmers should be moving stock urgently to protect them from bitterly cold winds.
Forecasts say snow is likely to fall to low levels in Wellington from late tomorrow and into Friday with the chance it may settle to sea level for a time.
With severe gales, snow to sea level and heavy rain it's likely there will be significant air travel delays tomorrow and Friday, along with road closures throughout the country.