A southwesterly airflow lies over New Zealand today.

Northland, Auckland, Waikato & Bay Of Plenty
The odd shower pushes in from the west during the morning, sunny spells break through at times. The Bay Of Plenty is mostly sunny however a period of afternoon cloud may bring a shower. Southwesterly winds.
Highs: 13-16

Western North Island (including Central North Island)
The odd shower, clearing in the afternoon as westerlies change southerly. Afternoon sunny spells break through.
Highs: 12-15

Eastern North Island
Mostly sunny with westerlies, winds change southwest in the afternoon bringing in a few clouds. Evening drizzle about Gisborne. 
Highs: 14-16

Wellington
Mostly sunny, light northwest winds change southerly in the afternoon.
Highs: 13-14

Marlborough & Nelson
Sunny, light winds for Marlborough. Southwesterlies for Nelson.
Highs: 13-15

Canterbury
Sunny with light winds.
Highs: 12-14

West Coast
Cloudy areas, the odd shower (mainly morning). Some sun breaks through in the afternoon mainly about South Westland. Southwesterly winds.
Highs: 10-12

Southland & Otago
Morning showers clear Southland then expect sunny spells. Otago is mostly sunny after any morning cloud clears. Westerly winds, breezy about Southland.
Highs: 12-13

By Weather Analyst Aaron Wilkinson – WeatherWatch.co.nz