North Islanders should rug up and turn their electric blankets on tonight as overnight lows drop by as much as 7C in some areas.
Wellington, Auckland and Hamilton are in for a chilly one as unseasonably warm nights make way for a more typical winter temperature tonight.
Cloud in the east of the North Island would keep temperatures in the area from dropping quite so dramatically, said Metservice meteorologist Kyle Lee, but in the lower and central parts of the island clear overnight conditions and light winds meant a lot of heat would be lost.
"The rest of the country's getting pretty low."
Auckland and Wellington's overnight lows were both forecast to drop by 4C tonight to 4C and 5C respectively.