From Weather Watch:
A front looks to be clearing off the North Island early on New Year's Eve (Monday 31st) and should leave behind sunny areas and some cloud. Over the South Island however a northwesterly airflow builds with rain on the West Coast and dry weather with high cloud out east.
Northland, Auckland, Waikato, Central North Island and BOP
A few morning showers possible especially about eastern Bay Of Plenty then clearing, expect a mostly sunny day otherwise with some cloud. Winds a bit breezy from the west or southwest, especially on western coastlines. Cloud may thicken a little overnight in the west.
Highs: 23-25
(20-50% chance of precipitation)
East of the North Island
Some morning cloud and the odd shower about Gisborne clearing with sunny areas increasing, mostly sunny with some cloud elsewhere. Winds will be tending west to southwest then easing in the afternoon. Later in the evening some high cloud develops.
Highs: 22-25
(10-40% chance of precipitation)
Western North island
Sunny areas and some cloud with brisk westerly breezes. Cloudy periods right on the coast south of Tarnaki with some sun now and then, cloud thickens south of Taranaki in the evening.
Highs: 21-22
(10% chance of precipitation)
Nelson & Wellington
Sunny areas and increasing cloud, northwesterlies pick up during the day gusting to gale force from afternoon about Wellington. A few spots of rain possible later overnight.
Highs: 20-23
(20% chance of precipitation)
Canterbury & Marlborough
Sunny weather with thickening high cloud, northwesterlies pick up from morning strong at times from evening. A few spots of rain possible at night.
Highs: 23-25
(10% chance of precipitation)
West Coast
Rain with breezy westerlies, heavy falls with thunderstorms possible at times mainly overnight.
Highs: 18-19
(70% chance of precipitation)
Southland & Otago
Dry weather with thick high cloud, brisk west to northwest winds. Overnight a period of showers moves into Southland, also central and southern Otago.
Highs: 20-23
(40-50% chance of precipitation)

Metservice:
