Temperatures around the country plummeted overnight, but it is expected to get a little warmer as the week progresses.
The Mackenzie District bore the brunt of the coldest night so far of winter, with Pukaki plummeting to -7C overnight.
Mount Cook airport, at the other end of Lake Pukaki, reached -4.8C.
Richard Green from WeatherWatch told First Up it had been pretty chilly in inland areas.
Taumarunui had the lowest temperature in the North Island, hitting -4C, while Taupō was -3C.
Auckland central city was around the 4 or 5 degrees mark, but some western suburbs down to 1 degree, Mr Green said.
Further south, in Wellington near the airport temperatures were about 10 degrees, with some southwest breeze.
In Marlborough it was -1C, in Christchurch -3C, central Otago was between -3C and -4C.
While there was plenty of frost about this morning, there wasn't a lot of snow.
After today, however, temperatures are expected to warm up as the week progresses.
Winter might seem it started late because it was the "third warmest autumn on record in New Zealand," Mr Green said.
For the weekend, a new system is coming in. meaning the western parts of both Islands can expect rain and heavy falls in some areas.
The front is likely to bring warmer temperatures tomorrow night, but the deep south may still feel the winter freeze.