A southwesterly airflow lies over New Zealand today moving around a large high pressure system in the Tasman Sea.

Northland, Auckland, Waikato & Bay Of Plenty
A few morning showers clear Auckland then sunny areas increase from afternoon, showers may not clear Northland till evening. The Waikato and Bay Of Plenty have a sunny day. Southwesterly winds.
Highs: 14-18

Western North Island (including Central North Island)
Any early showers clear then cloud breaking to a mostly sunny afternoon, south to southwesterly winds die out by evening.
Highs: 10-15

Eastern North Island
The odd shower about coastal fringes, not clearing till evening. Some tucked in areas (for e.g. Napier / Hastings) becoming mostly sunny in the morning. Cool southwesterlies die out later in the day.
Highs: 12-14

Wellington
A few morning showers clear then sunny spells increase, fresh southerlies die out in the evening.
High: 12

Marlborough & Nelson
Sunny with southwesterlies dying out in the morning, a frosty start for inland areas.
Highs: 10-12

Canterbury
Mostly sunny, showers about Banks Peninsula clear in the afternoon. Southwesterly winds die out in the afternoon.
Highs: 10-12

West Coast
Sunny, any morning cloud about Buller clears, light winds. Evening cloud and showers move into Fiordland.
Highs: 10-14

Southland & Otago
Mostly sunny, some cloud about coastal areas, there may be a few early clearing showers about coastal Otago. A few spots of rain possible about Southland later in the evening. Westerlies tend northwest by midday.
Highs: 10-12

By Weather Analyst Aaron Wilkinson – WeatherWatch.co.nz