A ridge sits over the South Island, before a northwest airflow develops over the southern part of the island – in Southland and Otago.

The South Island is mainly sunny through the day, although a few clouds float around Southland and parts of Otago, mainly near the coast.

The North Island has a southeasterly airflow, befre a ridge pushes onto the lower North Island overnight, and onto the upper North Island by dawn on Wednesday.
Showers move in towards Hawkes Bay, clearing in the afternoon – but hanging around Gisborne for much of the day along with cool southerlies.
It stays mostly sunny out west, with south to southwesterly winds.

– Aaron Wilkinson & Drew Chappell, WeatherWatch.co.nz