Auckland can also expect the odd morning shower before clearing to a sunny 17C.
The settled weather should continue through to the weekend as a high pressure system builds up over the country, Miller said.
Elsewhere, Whangarei can expect morning showers before clearing to 19C, while fine weather and tops of 17C-18C are also tipped for the Coromandel, Tauranga and Hamilton.
In the east, Napier can expect strong winds and gloomy skies, with showers ranging down the coast from Wairarapa to Wellington where the capital will hit a high of 12C as the overnight strong winds gradually ease.
In the South Island, most regions will enjoy fine weather as Nelson and Greymouth hit sunny highs of 15C, while Dunedin is expecting 17C and Queenstown a high of 14C.
Invercargill can expect morning showers and a high of 15C as a low pressure system builds up over the south later this week.
Today's weather
Whangārei Morning cloud and the odd shower, then fine. Gusty southwesterlies. 19C high, 9C overnight.
Auckland Fine, apart from the odd morning shower out west. Southerlies, strong in exposed places. 17C high, 8C overnight.
Hamilton Fine with southerlies. 17C high, 4C overnight.
Tauranga Fine. Gusty southerlies. 18C high, 9C overnight.
New Plymouth Fine. Gusty southeasterlies easing evening. 15C high, 8C overnight.
Whanganui Partly cloudy. Brisk southerlies easing evening. 16C high, 6C overnight.
Napier Mostly cloudy with occasional showers. Strong southwesterlies easing evening. 16C high, 10C overnight.
Wellington Partly cloudy with a few showers. Gale southerlies gradually easing. 12C high, 9C overnight.
Nelson Fine. Southerly breezes, dying out in the afternoon. 15C high, 4C overnight.
Christchurch Morning cloud, with a few showers about Banks Peninsula, becoming fine afternoon. 14C high, 3C overnight.
Dunedin Areas of morning and evening cloud, otherwise fine. 17C high, 8C overnight.