The central and eastern lower North Island are also due for sunshine, with cloud and the odd shower from Taranaki down through to Wellington in the west, Weatherwatch said.
MetService said the east coast of the South Island would have low cloud and occasional drizzle for a few days, with rain developing in Gisborne and Hawke's Bay.
Temperatures shouldn't feel too wintry this week, Niwa said.
Today's weather
WhangÄrei Cloudy periods, chance afternoon shower. Southwesterlies. High 16C, Low 6C
Auckland Cloudy periods, with possible morning fog. Isolated showers, mainly in the west. Light winds. High 16C, Low 6C
Hamilton Morning low cloud or fog, breaking to fine spells. Light winds. High 15C, Low 2C
Tauranga Fine. Light winds. High 16C, Low 5C
New Plymouth Cloudy periods, with the odd shower. Southeasterlies developing. High 14C, Low 5C
Napier Mainly fine, but becoming cloudy towards evening with the odd shower possible. Light winds. High 14C, Low 4C
Whanganui Cloudy periods. Light winds. High 16C, Low 5C
Wellington Cloudy periods and isolated showers. Light winds. High 14C, Low 6C
Nelson A fine day apart from some morning cloud. Light winds. High 14C, Low 3C
Christchurch Low cloud with possible drizzle morning and night, but afternoon sunny spells. Light winds. High 12C, Low 6C
Dunedin Low cloud with possible drizzle morning and night, but afternoon sunny spells. Northeasterlies. High 12C, Low 7C