A meterologists says an unseasonably warm air mass from the Coral Sea was contributing to the higher temperatures. Photo: 123RF
Hastings reached the highest June temperature on record for the country.
The Hawke's Bay city reached 25.7 degrees Celsius on Monday, which also qualified as a new North Island temperature record for the winter season of June-August, according to the National Institute of Water and Atmospheric Research (NIWA).
NIWA meteorologist Ben Noll said there were several factors behind the record-breaking warmth.
"We've seen an unseasonably warm air mass over New Zealand that originated in the Coral Sea. This combined with something called a foehn northwesterly air flow, which came over the North Island and warmed as it descended the terrain of the Central Plateau and blew into Hawke's Bay," Noll said.
"We also can't ignore climate change - setting a new national temperature record for June is consistent with Aotearoa's long-term warming trend, where we're seeing fewer cold extremes and more warm extremes."
Several other regions experienced temperatures above 20C on Monday, including Gisborne, Northland, and other parts of Hawke's Bay. Meanwhile, maximum temperatures in the South Island struggled to get above 10C in places like Christchurch and Queenstown.
Previously, the highest June temperature ever recorded by NIWA was 25.4C on 19 June 1988, also in Hastings.