Today sees a warmer airflow building over the country, starting in the South Island and heading northwards into Monday.

North Island:
A mostly dry day but a few isolated showers or drizzly patches possible here and there, mainly in the west where it will be a little cloudier too. North to north west winds developing, becoming stronger in Wellington.
Highs: 16 to 22

South Island:
Clouds thicken on the West Coast with heavy rain developing in Fiordland and lighter rain or showers further north. Most other places are sunny and dry with thickening high cloud. Winds from the NW pick up during the day becoming blustery but warm for southern and eastern areas.
Highs: 16 (West Coast) most other places, including Southland, from 19 to 25 degrees

– WeatherWatch.co.nz