Sub-tropical and northerly winds will continue to keep most of NZ warmer than average for the rest of this week and into the weekend.
However, by Sunday a colder change arrives from Australia dropping temperatures. (This same colder change is about to move into Adelaide, Melbourne and Hobart next day or so, and even up to Sydney).
A cold front moves up NZ this weekend, clearing the upper North Island later on Sunday and into Monday. Next week a large high from the Tasman Sea area is likely to move into NZ.