Masterton was the hottest in the land but scorching temperatures were felt throughout the country on Sunday with most of the country in the high 20s.
MetService said that Masterton was top with a high of 33C, but that was still 2 degrees short of the record January temperature of 35C in 2021.
Multiple other locations were close behind, with Auckland, Palmerston North, Hastings and Kawerau all hitting 30C temperatures or just above.
Just below at 29C highs were Hamilton, Kaitaia, Gisborne, Napier, Wellington and Blenheim.
If you were looking for a spot to cool off, the lowest high of the day was in Haast at 21C, MetService said.
But the heat on Sunday was mixed with scattered showers in many places, forecasters said.
A heavy rain warning is in place for Tai Rāwhiti north of Tolaga Bay for Sunday and into Monday.
Duty meteorologist Surprise Mhlongo said the area could see up to 175 millimetres of rain between 6pm Sunday and midday Monday.
Rainfall that led to a state of emergency in Westland on Friday and Saturday has eased overnight.
Rain or showers was expected for much of the country on Monday, MetService said.