Weather: The one place in New Zealand that won't be scorched this week revealed

Extreme heat is set to sweep the country on Sunday - and not just in the north.

Blenheim, Hastings and Napier could top 30degC, and MetService forecaster Ravi Kandula says most of the country will be affected.

"People can start to expect temperatures going up into the high 20s in the North Island. Parts of the east and the north will start to hit 30degC as well. Many parts of the South Island will start to reach the high 20s and 30s."

The hot weather should last for the next four or five days.

Blenheim is one of the hotspots, but Marlborough Mayor John Leggett says his region is used to dealing with extreme heat.

"The early morning walkers will be out on the Taylor River reserve, and the cyclists - and it will be batten down the hatches in the afternoon."

Still, he says people should check on their neighbours.

"Particularly people that are living alone and are not using air con… just make sure they're okay."

Mr Kandula says night-time will bring little relief.

"Overnight temperatures won't be cooling much at all. They could be as much as 6degC to 8degC above average."

The hot weather is set to stay until at least Thursday.

"We've got to be sun-smart, and with these heatwaves coming on, we've got to be mindful some people have health issues, and we've got to be vigilant as a community and make sure we look after them," says Mr Leggett.

Mr Kandula says only one part of the country won't be affected.

"Parts of the West Coast that are most exposed to windy conditions - Buller, Westland, parts of Fiordland should see temperatures that are much more seasonally appropriate."

A map from MetService has shown the terrifying heat on its way.
A map from MetService has shown the terrifying heat on its way. Photo credit: MetService

NIWA forecaster Chris Brandolino told The AM Show on Friday the weather will raise the chance of fire.

"The fire danger is going to go up. It's going to be difficult sleeping if you don't have the fan or AC," he said.

"This is going to be a prolonged, kind of accumulative event where maximum temperatures in the warmest locations either approach or exceed 35degC."

Newshub.