"In the North Island, eastern parts - Gisborne, Napier, Hastings and Masterton. Those areas are going to get a drop in north-west wind and are going to get warm."
As well as needing a swim and an icecream, the heat could lead to more serious issues in the coming days. Yesterday, the tar on State Highway 1 near Pūhoi, north of Auckland, started to melt.
Monday will be a cracker Auckland Anniversary holiday for those in the City of Sails too with a high of 26C expected - perfect for getting out to see the performers at the International Buskers Festival around the Viaduct and the annual Anniversary Day regatta.
MetService said a heat wave was defined by the World Meteorological Organisation as five or more days in a row of 5C above the average temperature.
It was forecasting many areas, especially in the east, would see consecutive 30C days from today through to the end of the working week.
The warm, humid air was also going to make for some sultry nights, with Nelson, Tauranga and Auckland not expected to cool below 20C.
The warmest places today were in the South Island and particularly in the Nelson region and parts of Canterbury.
Cheviot got the award for the hottest temperature today at 28.5C. Methven reached 28C, as did Gisborne.
Meanwhile, there are a number of heavy rain and strong wind warnings for parts of the South Island tonight, but they were expected to cease overnight or in the early hours of the morning.