MetService has issued heat alerts for 18 towns and cities across the country on Monday as temperatures reach soaring levels.
It comes after Auckland was hit with its fifth hottest day on record and the hottest day in four years.
However, with a cold blast on its way, Kiwis might want to make the most of the hot weather while they can.
Heart alerts have been issued for 18 towns and cities including Kaitaia, Paihia, Russell, Auckland, Hamilton, Tokoroa, Te Kūiti, Whakatāne, Taupō, Taumaranui, Napier, Masterton, Whanganui, Palmerston North, Levin, Wellington, Blenheim and Kaikōura.
Auckland is currently seeing the highest temperatures, with 29.8C recorded in northern parts of Auckland, such as Whangaparaoa.
"There's a lot of heat across the country and these temperatures could get higher," MetService meteorologist Clare O'Connor told Newshub.
She said the sudden boost in high temperatures is a result of a low-pressure system that moved down from the north, bringing hot and humid air.
Her advice for people in the city of sails is to "stay sun safe" and seek shade whenever they can. She warned staying hydrated is especially important during high temperatures.
"Currently, you've got 28.4C at Auckland Airport, which is quite a way out of the city, but surrounding temperatures aren't far off," she explained.
O'Connor said although it has been hot in recent days, the North Island's East Coast has been seeing less heat.
It comes after a heavy rain warning was issued for Tairawhiti/Gisborne, north of Tolaga Bay, at 9pm last night.
"Despite that warning expiring at 2pm today, south of Tolaga Bay, a heavy rain watch continues until 4pm," O'Connor explained.
"Gisborne isn't as hot as usual today, they are seeing more rain and humidity, with a high of 22C."
She said any hot temperatures are set to die down for the whole country with a cold southwesterly change on its way, set to reach the far south of the South Island late tonight.
"There will be a cold start tomorrow morning for many Kiwis, with Queenstown potentially dropping to 3C on Tuesday night," she said.
This will reach the lower North Island at midday, before crossing the rest of the North Island in the later half of Tuesday.
"From Tuesday night to Wednesday, people in Auckland will be waking up to temperatures of 15C compared to the usual 19C, on Wednesday morning," she said.
"If you don't feel the drop in the evening, you'll definitely feel it in the morning.
"I'm sure people will be pleased to hear that," she laughed.
