A high pressing in across the country could mean another frosty night for many parts of the country.
The weather is also far from settled in some regions, with cold southerly and sleet expected in some regions this evening.
A high rolling in overnight and into tomorrow will see frosts likely develop in both islands, Weatherwatch's Philip Duncan said.
As the last of the southerly blast moves through the eastern regions, Gisborne can also expect strong winds and rain/showers later today.
"Northern Hawke's Bay is also caught up in the windy, showery, cold southerly with sleety showers inland into the ranges, turning to snow showers on the summits," Duncan said.
"Overnight and into Sunday the high rolls in - and frosts develop for the coldest most sheltered coldest areas, especially the South Island.
MetService is forecasting fine days ahead for Auckland, with 15C highs.
But the overnight lows to remain in single digits at least until overnight Tuesday.
Some eastern parts of the North Island may also be at risk of frost on Monday morning.
But good news is on the horizon and a westerly flow next week will bring mild weather again to most regions.