MetService advises anyone out and about in the sunshine to remain sun smart: slip, slop, slap, and wrap, and make sure you have sufficient fluids to keep you hydrated, says MetService Meteorologist Clare O’Connor.

"Heat alerts will be issued for locations that are reaching their highest temperatures – keep up with your local forecast to make sure you are the most prepared you can be for the day."

But cooler air is on the horizon.

“A fresh southwesterly change early Monday will be in sharp contrast to the hot weather of the weekend," says Clare.

"Maximum temperatures are forecast to barely reach the high teens early next week, in some places this is even lower than recent overnight temperatures, which might be appreciated by anyone who has been struggling to sleep this last week.”

Monday January 15
A front will move slowly northwards onto the southern and central North Island during Monday, while an increasingly humid northerly flow affects northern New Zealand.

A low originating in the subtropics should also move into the area west of the upper North Island.

This combination should bring areas of heavy rain to the North Island, however there is uncertainty as to which areas will most likely be affected.

Consequently, there is low confidence of rainfall amounts reaching warning criteria about many northern and western North Island areas from southern Northland through the central high country to Kapiti and the Tararua Range, including the Gisborne/Tairawhiti region.

Localised downpours are also possible.

Tuesday January 16
The low is likely to lie west of the North Island, with a humid and wet northerly flow affecting northern and central parts of the North Island.

This should bring areas of heavy rain to many northern and central North Island areas, however there is uncertainty as to which areas are most likely to be affected.

Consequently, there is low confidence that rainfall amounts could reach warning criteria over all northern and central North Island areas from Taranaki, the central high country and Hawke's Bay northwards on Tuesday.

Thunderstorms and localised downpours are also possible in these areas.

Wednesday January 17
A humid northerly flow should continue to affect parts of the North Island on Wednesday, but there is continuing uncertainty about which areas may be affected by heavy rain

There is low confidence of warnable rainfall amounts about northern and central North Island areas from Taranaki and the central high country northwards on Wednesday.

Thunderstorms and/or localised downpours are also possible in these areas.

Thursday January 18 2024
A weak ridge of high pressure should spread over central and southern New Zealand on Thursday, while the humid northerly flow continues to affect the northern half of the North Island.

At this stage, there is minimal risk of severe weather over New Zealand, however isolated afternoon and evening thunderstorms are possible over the northern and central North Island with locally heavy rain.