Parts of Auckland were sweltering in 30C temperatures at lunchtime today and WeatherWatch forecaster Philip Duncan says the city's official reading could reach 30C later today.
The official temperature was 28C at 12.30pm, but there were unofficial readings of 30C at Howick and Pakuranga in the east and Henderson in the west, he said.
Mr Duncan said most years parts of Auckland reached 30C, but temperatures rarely got higher than 30C.
"Officially it is less likely because the weather stations MetService have are at Whenuapai and Auckland Airport, which are much cooler than in downtown Auckland."
A lack of wind in Auckland was contributing to the hot weather, but a few cloud build-ups could prevent higher temperatures later in the day, Mr Duncan said.
The east coast of the North Island, from Gisborne to Hawkes Bay, is experiencing temperatures in the low 30s and the rest of the North Island was warm.
Mr Duncan said the South Island was not as warm with a fair bit of cloud and rain on the West Coast.
Christchurch was 24C at lunchtime.
Auckland's hottest recorded temperature occurred on February 12, 2009, when a MetService weather station at Whenuapai Air Base peaked at 32.4C.
This equalled the previous high recorded in the Auckland Domain in February 1872, 137 years earlier.
Meanwhile, WeatherWatch forecaster Philip Duncan today issued a warning on the North Island's east coast beaches from Cyclone Victor, which has been tracking southwards and weakening towards New Zealand.
He said forecasters had been talking all last week about the dangers to New Zealanders from the swells and big waves created from the leftovers of the cyclone.
"I'm not sure if what happened in Bay of Plenty last night was anything related to Victor with that boy drowning, but this is what we see almost every time there is a cyclone that is offshore.
"We almost always see a death or someone being swept out to sea.
"So we are trying to put out a message that even if the weather is really lovely at your camping ground or your beach there is quite a dangerous storm well out at sea that is changing our conditions on our east coast beaches," he said.
Mr Duncan said people should be aware there is an offshore system and use common sense and be aware if they were on rocks, have children or are not a good swimmer.