Auckland experienced its fifth hottest day on record yesterday and the hottest day in four years, reaching 29.7c.
Niwa announced the record-high heat on Sunday, with parts of Wellington also experiencing their hottest day in two years as temperatures soared above 28c.
The hottest location was in Masterton which reached a whopping 33c.
It came as Metservice issued multiple warnings and watches across the country, with torrential rain expected to hit Gisborne and Westland through today and into tomorrow.
Severe thunderstorm warnings were also issued for Hastings, Rangitikei, Kāpiti Coast, Horowhenua, Tararua, Palmerston North, Carterton and Masterton districts throughout yesterday evening but were all lifted.
In Taumarunui, Taupō, Hawke’s Bay, Taranaki, Taihape, Wanganui, Manawatū, Tararua, Kāpiti-Horowhenua, Wairarapa and Wellington, severe thunderstorm watches were also lifted at 9pm last night.
An orange heavy rainfall warning came into effect for Gisborne at 9pm last night and 2pm today.
Further south, a yellow heavy rain watch is also in place for Westland and Grey districts until midday today, with thunderstorms and localised downpours of 25 to 35mm/h possible.
Last week the West Coast was hit with a state of emergency due to torrential rain that caused rivers to rapidly rise and forced the closure of State Highway 6.
However, Metservice says Monday's rain will move quickly so it shouldn't have as large an impact on the area, as last week's downpour.
However, it isn't all bad news with a drop in humidity expected as overnight temperatures are forecasted to hit single digits in the South Island this week.
Further north it's a similar story, with temperatures expected to drop to half of the current heat, with the highest temperature across the country this Wednesday night not surpassing 15c.
With Australia set for a tropical cyclone in the coming days, weather down in New Zealand could be slightly impacted.
The cyclone is set to land down under on Monday but at this stage, forecasters aren't predicting whether it will hit New Zealand or just how severe it would be if it did.
