MetService lead meteorologist Mark Todd said the coldest areas this morning were in the central North Island high country, but a layer of cloud kept temperatures higher than expected in the South Island.
"Christchurch, which you would expect to be fairly chilly, is sitting at 7C, so not too bad.
"That cloud is acting as a good insulator."
Scattered rain was forecast in Southland and Clutha today, and isolated showers for coastal areas from Northland down the North Island's west coast, and on the east coast from Wairarapa to south of Mahia.
Apart from those areas it was shaping up for a fine day, Todd said.
"Things should continue to improve through the day, as a high pressure system continues to slowly build over the country."
Tomorrow and Saturday were looking like much of the same, as the ridge of high pressure moved east over the country, bringing a period of settled weather.
However, frosts were likely with the clear conditions, and icy conditions could affect some inland roads.
"It is looking to be calm and clear the next few days so will continue to be chilly overnight," Todd said.
A front was expected to move east over the country on Sunday, bringing a period of rain to many places, especially in the west - falling as snow about the mountains.
The front cleared the North Island on Monday, and a broad trough moved slowly northeast over the South Island.
Today's weather
Whangārei
Fine spells, a few showers. Southwesterlies. 15C high, 8C overnight.
Auckland
Fine spells. A few showers, mainly about the western suburbs first but spreading east during the morning. Southwesterlies. 14C high, 7C overnight.
Hamilton
Fine spells with early frosts. A few showers developing morning. Light winds. 12C high, 1C overnight.
Tauranga
Mainly fine but some afternoon cloud and chance of a shower. Southwesterlies. 14C high, 5C overnight.
New Plymouth Fine spells. A few showers, clearing from afternoon. Light southwesterlies. 13C high, 4C overnight.
Napier Fine, morning frosts. Light southwesterlies. 14C high, 3C overnight.
Wellington The odd early morning shower clears to a fine day. Frost in sheltered suburbs. Light winds. 12C high, 5C overnight.
Nelson A fine day with morning frosts. Light winds. 13C high, 0C overnight.
Christchurch Mainly fine, some cloud morning and evening. light winds. 12C high, 1C overnight.
Dunedin Fine spells. Southwest breeze. 12C high, 7C overnight.