"It's mostly around northern parts of the country there will be showers, some heavy, but mostly in Northland and the rest of the areas it's about the ranges and during the afternoon. The southwesterly breeze brings generally cooler temperatures."
Wairarapa and Gisborne will stay hot, on temperatures up to 27C.
The heat is causing alarm for animal lovers.
A dog in Wellington suffered a burned paw after being taken for a walk in blistering conditions, a timely reminder for animal owners to take note of hot footpaths.
#SHARE “The 5 second rule. If you can't place your hand on the pavement for 5 seconds it is too hot to walk your dog....
Posted by Wellington - LIVE on Thursday, 7 December 2017
Meanwhile, several fronts are moving over the South Island.
Rain will be heavy in the west, including Buller and Westland, and Canterbury, Otago and North Otago will get occasional rain this afternoon.
The fronts will then weaken as they move north, bringing a few showers to most areas on Wednesday and Thursday before dying off on Friday.
The South Island will get occasional rain in lower parts before it clears on Friday, she said.
Canterbury's forecasted showers have even perked the interest of police, reminding motorists to take it easy on the roads if it appears.
Advisory Alert
We've had intelligence to suggest that we might be experiencing a natural phenomenon over the next...
Posted by Canterbury Police on Monday, 11 December 2017
The warm weather has also called for several councils to put in water restrictions.
Hamilton last week raised its restriction to level 2, meaning using sprinklers on alternate days, Tasman District remains on level 1.
Councils in Wellington, Hutt Valley, Napier and New Plymouth all have residential sprinkler and irrigation bans.
Matamata-Piako District Council still has heavy restrictions in place because of a leak in Morrinsville, but residents are now allowed to have showers.
Meanwhile, New Zealand Transport Agency journey manager Lee Wright said the bitumen had begun "bleeding" due to the heat in some areas, including Marlborough.
Some road surface temperatures were likely to continue to be higher than 50C this week.
"With the recent arrival of the hot temperatures, some roads are showing signs of 'bleeding seal' or sticky surfaces. This happens where the bitumen melts and rises above the chip seal road surface."
Wright advised motorists to slow down if they saw a sticky black road surface ahead.
Tips for driving on "bleeding" bitumen
* Slow down before you reach the newly sealed surface
* Avoid braking
* Remember 30km/h is appropriate on a newly sealed surface
* Drive too fast and you'll send chips flying,
* Drive too slow and the road surface sticks to you.
