Winter showed its mighty hand early today, as temperatures in parts of the central North Island dropped to a teeth-chattering -11.2C.
It may have been the first time temperatures have dropped that low this winter, but will possibly not be the last time, the MetService said.
The coldest part of the country early this morning was in Waiouru, which felt the bite of -11.2C shortly before 6am.
St Arnaud, in the Tasman district, was the next coldest place to be early today, clocking a temperature of -9.4C around the same time, while Pūkaki aerodrome came out in third place, recording a -7.7C temperature early on.
MetService meteorologist Lewis Ferris said a high pressure weather system sitting over the country the past few days had resulted in the very cold temperatures.
Aucklanders woke up to a chilly start to the working week also.
Temperatures ranging from -1.6C at Auckland Airport to -1.5C at Ardmore were recorded early today.
An otherwise sunny Monday is forecast in the City of Sails - but motorists have been warned of foggy conditions in and around the region.
Motorists heading into the city faced some delays after a crash just after the Carrington Rd overbridge.
The incident was reported at 6.25am and Waka Kotahi NZ Transport Agency told drivers to "merge with care to pass and expect delays".
Train services have been cancelled between Britomart and Penrose on the Onehunga line due to a train fault at Britomart.
Those using the Southern line should know that services towards Papakura will not stop between Britomart and Ōtāhuhu, Auckland Transport said.
"Services towards Britomart will stop [at] all stations via Newmarket."
A temperature high of 15C is forecast in the City of Sails, with an overnight low of 9C.
In Hamilton, -3C was recorded early on, and those in the city are told to expect a frosty and possibly foggy start to the working week.
"Plenty of freezing fog around Waikato and a few other places this morning," the MetService said.
"A good situation for fog is when New Zealand is sitting on the western side of a high, like we currently are."
A mainly fine day is on the cards in Hamilton, however, with a high of 12C and overnight low of 3C.
In other parts of the North Island, Whangārei recorded a temperature of 8C this morning, 3C in Tauranga, 1C in Gisborne, 3C in Taupō, -1C in Napier, -4C in Masterton, 8C in Palmerston North and 9C in Wellington.
The warmest place in the country just after 6am was Methven, which clocked a somewhat cosy 13.4C.
Further south, mostly fine conditions are forecast in Nelson, Marlborough, Canterbury, Otago and Southland.
MetService says there will be a few areas of morning low cloud or fog first off, but high cloud is expected to increase from the south; while northwesterly winds are set to strengthen in and around Southland.
Those in Nelson are experiencing about 1C to start off the day. In Blenheim, the temperature is -2C, 2C in Christchurch, -1C in Queenstown, 2C in Dunedin and 8C in Invercargill.
While people in Stewart Island are waking up to a somewhat warmer morning - with 10C recorded shortly before 6.30am.