A belt of nasty weather that hit much of the country is set to be replaced by a high-pressure system that will lock in the cold air and bring clear skies and some bitterly cold overnight temperatures in the South.
Weatherwatch.co.nz said a cold southerly covering the country was fading away as the high pressure built from the west. The high would bring in blue skies and sunshine, but with snow on the hills in many places, the conditions were right for sub-zero temperatures and a run of hard frosts, especially in the South.
Low temperatures would be widespread in the South Island on Tuesday and Wednesday mornings, with lows between -3degC and -6degC inland. Both Alexandra and Queenstown looked set for mornings in the minuses for the rest of the week.
Coastal areas would be less hard-hit - Dunedin residents could expect to wake to single-digit temperatures for the rest of the week.
The forecast for frosty nights comes as MetService predicts one of the coldest winters in years.
Meteorologist Georgina Griffiths said New Zealand was entering a colder-than-normal winter.
"It's been a little while since we've had a cool or anywhere average winter... the last time we had one was in 2015," Ms Griffiths told Newshub
"The bottom line for June is great news for ski fields, not so good for power bills."
"That abnormal heat we had to start the year is well and truly gone."
