A front moves north of the North Island today bringing with it some rain, the South Island has a southwesterly airflow with showers in the west and south.

Northland, Auckland, Waikato & Bay Of Plenty
Dry at first, rain moves in late morning with the chance of a heavy fall then easing in the afternoon with sunny spells developing as northwesterlies change southwest. Northland may only see showers, not clearing till evening.
Highs: 17 – 19

Western North Island (including Central North Island)
Morning rain, possibly heavy (mainly about Taranaki) then clearing around midday with sunny areas increasing as northwesterlies change westerly.
Highs: 13 – 17

Eastern North Island
Mostly cloudy with spits of rain, clearing from the south in the afternoon and becoming mostly sunny as a front moves northwards. Gisborne may not see spits till afternoon, clearing there in the evening. Northerlies tend northwest as the front clears. 
Highs: 18 – 22

Wellington
Morning rain clears then mostly sunny, blustery northwesterlies ease in the evening.
Highs: 15 – 16

Marlborough & Nelson
Any early rain clears then mostly sunny, northwesterlies ease tending to the south in the evening for Marlborough. Nelson has westerly winds.
Highs: 17 – 19

Canterbury
Mostly sunny with northwesterlies, winds change southwest in the afternoon with a few clouds spreading north. Cloud breaks away at night with winds dying out.
Highs: 18 – 20

West Coast
Heavy showers ease, clearing evening although the odd shower may remain about Fiordland. Westerlies change southwest in the morning.
Highs: 13 – 14

Southland & Otago
Morning showers for Southland then clearing with sun developing, only a few brief showers move through coastal Otago in the afternoon. Central Otago has morning high cloud then mostly sunny. Northerlies change west to southwest during the morning.
Highs: 13 – 19