A southwesterly airflow lies over the country today, there could be some instability for the lower and eastern North Island as a change moves through.

Northland, Auckland, Waikato & Bay Of Plenty
Showers, westerlies change southwest in the morning then breaking to sunny areas. Another round of showers in the afternoon, some may be heavy for Waikato and Bay Of Plenty with a chance of thunder, clearing in the evening.
Highs: 15 – 17

Western North Island (including Central North Island)
Showers, some may be heavy, clearing late afternoon or evening as westerlies change around to the southeast. Chance of a frost overnight for inland areas.
Highs: 9 – 15

Eastern North Island
High cloud, chance of a spit. Southwesterlies freshen pushing northwards during the morning and afternoon bringing showers, some may be heavy with thunder and hail, clearing in the evening.
Highs: 15 – 19

Wellington
Cloud increases in the morning with southerlies freshening, a few showers move in also then clearing in the afternoon. Southerlies die out at night.
Highs: 13 – 14

Marlborough & Nelson
Dry at first with sun, cloud increases during the morning (first for Marlborough, secondly in Nelson) bringing showers, showers may be heavy in the afternoon about the ranges of Nelson. South to southwesterly winds, tending northerly in the afternoon for Nelson.
Highs: 15 – 17

Canterbury
Partly cloudy, a few showers about North Canterbury clear from the south during the morning. Fresh southwesterlies (strong about the coast) die out in the evening.
Highs: 12 – 16

West Coast
Showers clearing from the south with sun increasing, showers last to clear Buller late afternoon. Southwesterlies ease, dying out by evening.
Highs: 14 – 15

Southland & Otago
Showers ease and clear in the morning, some coastal areas not clearing till the afternoon then sunny areas increase, a few snow flurries to 500m. Cold southwesterlies (strong about the coast) die out in the evening.
Highs: 10 – 14