A large low pressure system is centred to the east of New Zealand today slowly rotating a cold southwesterly airflow over the country bringing unsettled weather to most regions.

Northland, Auckland, Waikato & Bay Of Plenty
Showers, heavy at times with possible thunderstorms and hail as westerlies freshen. Winds change southwest overnight.
Highs: 13-17

Western North Island (including Central North Island)
Morning rain, possibly heavy with thunderstorms and hail then easing to showers around midday. Showers may reinvigorate late afternoon for a time Taranaki northwards bringing a heavy downpour, some hail and perhaps a further thunderstorm. Wet weather clearing for most during the evening. Snow down to 1000 or perhaps 900m about the Central Plateau. Northwesterlies change south to southwest in the evening.
Highs: 8-14

Eastern North Island
Rain for the Wairarapa spreads into Hawkes Bay late morning then Gisborne by mid afternoon. Before rain moves in expect sunny areas and some high cloud and once rain moves through (lasting a period of perhaps 3 hours max) conditions easing to the odd shower and southwesterlies freshen.
Highs: 13-16

Wellington
Early showers clear then expect some sun, breezy northwesterly winds change southerly in the afternoon. Evening showers.
High: 12

Marlborough & Nelson
Mostly sunny with westerly winds tending southerly in the afternoon. There may be some morning cloud with the chance of a shower for Nelson then breaking away.
Highs: 11-13

Canterbury
Mostly sunny, showers develop over Banks Peninsula with heavy falls and a chance of hail, spreading elsewhere late afternoon or evening as southwesterly winds freshen. Evening snow flurries to 600m.
Highs: 8-12

West Coast
Any early showers clear then expect sunny weather with southerly winds.
Highs: 8-12

Southland & Otago
A mix of sun and cloud, there may be a few showers about coastal Southland then spreading elsewhere during the afternoon. Parts of inland Otago may remain fairly dry after a very cold start. Cool southwesterly winds picking up after midday.
Highs: 7-11

By Weather Analyst Aaron Wilkinson – WeatherWatch.co.nz