A northwesterly airflow lies over New Zealand today. A front within this flow slowly moves northwards over the South Island during the day mainly affecting the West Coast with heavy rain.

Northland, Auckland, Waikato & Bay Of Plenty
Morning cloud then sunny spells, could be an early shower for Waikato and Bay Of Plenty. Light west to southwesterly winds, afternoon northerlies for Bay Of Plenty.
Highs: 17-21

Western North Island (including Central North Island)
Cloudy areas, may be a shower or two mainly morning. Northwesterly winds.
Highs: 15-18

Eastern North Island
Sunny weather with northwesterly winds, an afternoon easterly may spring up for a time about coastal Hawkes Bay before dropping away in the evening.
Highs: 21-22

Wellington
Cloudy areas, may be a spit otherwise mainly dry. Gusty northwesterly winds.
High: 14-15

Marlborough & Nelson
Mostly sunny with some high cloud, west to northwesterly winds.
Highs: 18-22

Canterbury
High cloud, some sun at times. North to northwesterly winds ease later in the day.
Highs: 20-22

West Coast
Cloudy with showers, rain about South Westland with heavy falls spreads into North Westland by late afternoon. North to northeasterly winds.
Highs: 13-15

Southland & Otago
Mostly cloudy skies about Southland with cool temperatures, patchy rain or showers with dry spells increasing from afternoon. Mainly dry skies by evening. Winds are light tending southerly or southwest by midday. Otago has cloudy areas, there may be a spit or shower otherwise conditions are looking mainly dry with light winds.
Highs: 12-19

By Weather Analyst Aaron Wilkinson – WeatherWatch.co.nz