New Zealand is under flat air pressure at the moment, not a high and not a low. There will be no severe disturbances around the country this week weatherwise. A large part of the country will enjoy fine weather for the next few days ahead but not everyone.
Clouds are likely to spread over the western side of the North Island – also Northland and western Southland – held up by the ranges of New Zealand (and making for sunnier weather inland and to the east).
In Northland and Auckland widespread light showers or even patchy rain is expected after Wednesday afternoon, due to a warm front associated with a weak low just to the northwest of the North Island. By Thursday this showery area intensifies a little further in the western North Island, mainly from Taranaki up to Northland.
These western showers fade on Friday but on Saturday heavy rain returns to the West Coast (reaching the North Island at night).
As a result of this set up the eastern side of the South Island will be persistently sunny and warm for this time of the year. Maximum temperatures will be several degrees higher than usual.