MetService Meteorologist Claire Flynn said MetService recorded a high of 25.7C at Tauranga Airport on Wednesday.
Yesterday reached 23C with Thursday's temperature supposed to drop back down to 22C and 20C on Friday.
Ms Flynn said the hot weather had moved across to the top of New Zealand from Australia and should stick around until Friday when morning showers and afternoon rain was predicted.
Temperatures were about normal for this time of year, she said.
Monte Gelato gelato technician Jamie Vuglar said there had definitely been an increase in gelato lovers since Sunday.