Heatwave criteria is being challenged through the South Island's interior as the North Island enters a significant dry spell.
Daytime temperatures are forecast by WeatherWatch.co.nz to exceed five degrees for five days or more through inland parts of the South Island from today onwards.
In fact, inland areas will be more 10 degrees above normal in the days ahead through both islands as sub-tropical and Australian airflows drift over New Zealand with large high pressure parked in the Tasman Sea.
"The hotter weather shifts into the North Island this weekend but varying wind flows means the North may not reach heatwave criteria.
"But as we've been forecasting all week, the North Island is now entering a very dry phase with little to no rain forecast for the rest of November in most regions.
Thunderstorm forecast for Sunday.
"However there may be some afternoon downpours that bubble up around the North Island, mostly through central areas or around the ranges.
"Isolated inland thunderstorms may also be possible. So, very locally some people may get a decent drop of rain but for the most part it's looking much drier than normal and warmer than usual across the North Island and eastern side of the South Island."