One unofficial peak was recorded on website Wairoa Weather, listing a maximum for the town of 36.6C at 3.44pm - a rise of 4C in half an hour and preceding a near-immediate drop back to 34.6C.
MetService meteorologist Emma Blades said that peak was however unlikely, because temperatures elsewhere in the region from Wairarapa to Gisborne were steadily rising.
But Barry Gasson, of Wairoa Autobodies and a veteran volunteer firemen in the town, looked at his thermometer and said: "It's 34C, and that's in the coolest place around here."
Weather website AccuWeather was posting a maximum of 32C in Waipukurau.
Metservice meteorologist Emma Blades said that while some showers were forecast over the weekend, the weather would remain "dry" and it could be midweek before stifling overnight temperatures would start to get cooler.