Waipukurau hit a sweltering 39C yesterday - if a public thermometer in the town is to be believed.
The apparent high would seem to support a prediction by climate scientist Dr Jim Salinger earlier this week that temperatures in parts of the East Coast could reach 40C or more.
WeatherWatch.co.nz said the country would continue to swelter with mostly dry and sunny skies over the nation with just "a few blemishes" on the fringes.
The mercury was also expected to top 30C today in the north and east of the South Island between Blenheim and Dunedin.
In the North Island, Wairarapa, inland parts of Hawke's Bay, Tauranga, Hamilton and possibly Palmerston North, were also expected to swelter.
Weather forecaster and analyst Richard Green said Northland and Gisborne would see a few cloudy areas with the risk of a drizzly shower.
The deep south could see "one or two showers pick up" and southern Fiordland should see "some rain or showers", although an easing was likely later.
Winds continuing to blow from the east over the Far North and eastern parts of the country would not prevent temperatures climbing to fairly healthy levels overall, Mr Green said.
Meanwhile, Waitangi Day on Wednesday next week is likely to be mainly settled for most areas as the country bathes under yet another anticyclone, he said.
Temperatures are likely to be in the low to mid-20s for most centres.
However, inland areas could reach the 30C mark.
The hotspots will likely be Hanmer Springs and Alexandra in the South Island, and Kawerau and inland from Palmerston North.
The dry spell could be broken on Sunday and Monday for parts of the country, Mr Green said.
"Moving in from the Tasman Sea a frontal system looks to deliver a period of rain for western and northern districts, and now the chance of a band of rain or a period of showers moving across eastern parts of the Mainland."
However, Hawke's Bay, which was the driest part of the country, would probably miss out on much of next week's rain, Mr Green said. APNZ