Weather: Where this weekend's searing heat will be worst

NIWA has revealed the areas set to be seared by the worst of this weekend's sweltering heat.

A mass of hot air is heading across from Australia, and is forecast to push New Zealand to near record-breaking temperatures.

Eastern areas will be hit the hardest, with the east of the South Island expected to feel the burn over the weekend. 

"Over towards eastern Canterbury, northeastern Otago, interior Otago - even Hawkes Bay - we're talking a chance of temperatures to exceed 30C," NIWA meteorologist Chris Brandolino said in a Facebook forecast video.

"If it gets to 30C in November, what makes this unusual is that some places in Canterbury or the Marlborough region, or Hawke's Bay as we go into next week, they could be pushing towards all-time November high temperatures," added fellow meteorologist Ben Noll.

Appearing on The AM Show on Friday, Brandolino said it's incredible such high temperatures could roast the country so early in the month.

"The warmest temperatures in November… have all occurred mid-to-late November," Brandolino said.

"The fact that [the warm temperatures are] happening on the second, the third, the fourth, the fifth of November, that's impressive."

And Noll warns this heat isn't going to be a "one-hit wonder".

"That warmth is expected to hold on as we go through the remainder of next week. In fact, the second wave will come across as we go into late next week… so this is going to last over the next week to two weeks here."

Brandolino said the tropical weather will continue for the next three months. 

"Quite frankly, this is something we may see repeated again," he told The AM Show.

"That is our kind of thinking for the next three months. We think there will be a lean towards an average or above-average temperatures for much of New Zealand."

But he did warn that there were a few "large doses" of rain forecast in November that could bring flooding, especially to western parts of the country.