With temperatures dropping below zero during this morning's big chill, Kiwis are being urged to take extra care behind the wheel now winter has arrived.
Pukaki Airport - near Twizel in the South Island's Mackenzie District - was among the country's coldest spots overnight, dropping to a freezing -7C, MetService said.
Dunedin was the coldest main centre as it hit its lowest temperature this year of -4C, while Christchurch residents shivered through a low of -3.4C.
By 8am, the mercury was still at -3C in Queenstown and Timaru, while in the North Island Taupo residents brave enough to go outside were faced with an icy -4C.
With such conditions, police urged drivers not to take "careless risks".
"Driving in winter is not the same as driving in summer," national road policing manager Superintendent Steve Greally said.
"Extreme weather conditions such as ice, snow, fog and wet weather can hit quickly, so people need to be prepared ... and know how to handle the vehicle they are driving."
— WeatherWatch.co.nz (@WeatherWatchNZ) June 18, 2019
NZ Transport Agency's Greg Lazzaro said motorists should check forecasts and consider putting off or avoiding driving if the weather was bad.
They should also aim to drive during daylight hours because night conditions can bring multiple hazards.
"When you're on a wet, icy, or snowy road, it's important not to brake suddenly or to accelerate quickly, as you could aquaplane or skid," Greally said.
"People need to watch their following distances, make sure before they set out that their headlights and windscreen wipers are working, and check weather reports in alpine areas."
Hamner Forest in Canterbury highlighted how different conditions could be between summer and winter, the National Institute of Water and Atmospheric Research said.
Residents in the area had now experienced a 45.8C swing in temperatures this year, having hit a high of 38.4C on January 31 and now a low of -7.4C overnight.
With a min temp of -7.4˚C, Hanmer Forest is now the proud owner of a 45.8˚C temp range this year‼️
Max: 38.4˚C on 31 January 🥵 Min: -7.4˚C on 19 June 🥶
But cold as it was overnight, Jones has seen worse. The temperature plunged to -20C in the area a couple of years ago, he said.
#Auckland: Inland parts of the region hovering close to an air frost (just below 1 degree at 7am), so there will be some decent frosts out there, and some ice on the wind screen. Take it easy for the commute, too ^GG
Auckland is set for a top of 14C before dropping to an overnight low tonight of 8C.
Temperatures then warm to 16C and 17C on Thursday and Friday, although persistent rain is forecast for most of the North Island from tomorrow and could sour the mood.
Whangārei residents can expect a top of 16C today with tonight's forecast low of 12C about 5C higher than last night's low of 7C.
Hamilton and Tauranga can expect sunny tops of 13C today. The chilly frosts will continue in Hamilton where another overnight low of 1C tipped tonight before rain hits from tomorrow.
Only one district in New Zealand has zero frost risk on Wednesday morning 😱
New Plymouth and Napier are both expecting sunny highs of 13C, while Wellington is set for a top of 11C with a chance of afternoon showers.
Christchurch is tipped to hit a sunny high of 11C after this morning's frosty start before the mercury again plunges below zero for an overnight low of -1C.
Dunedin is expecting a high of 11C and a low of 3C tonight.
A frontal rain band approaches the country on Thursday which is forecast to bring precipitation to most places through into Friday with a wet weekend ahead for some. Stay up to date with current forecasts at https://t.co/Yjbq0jxdqz ^Lewis pic.twitter.com/sXhnVpvmPk