More heatwaves likely as climate change drives hotter summers across Aotearoa

Heat alerts have been issued for Whakatāne, Napier, Hastings, Motueka, Blenheim, and Kaikōura.

Scorching temperatures reaching the high 30s are already beginning to arrive. Photo / MetService

Earth Sciences New Zealand’s manager of climate, atmosphere and hazards, Nava Fedaeff, told the Herald warmer temperatures are set to continue.

She warned that the likelihood of serious heatwaves in New Zealand will increase, causing a threat to health, animals and agriculture.

“I think the longer-term projections are that the number of extreme heat days and heat waves are going to increase in New Zealand,” Fedaeff said.

“We will see new temperature records and things like that set in the future, not necessarily with this event coming, but something of that flavour,” she said.

Fedaeff said we may even see another heatwave-like event this summer.

MetService said these sweaty temperatures are caused by the remnants of the Australian heatwave earlier this week. Photo / Getty Images

What brings these temperatures to New Zealand?

Fedaeff said that when extreme heat events impact New Zealand, it typically starts with hot weather over Australia.

“There’s generally a high pressure over Australia … They have got a lot of continental heat, and then it needs to come our way.”

She said we would need to have a westerly or a northwesterly wind flow to bring the warm air over us.

“All of those things kind of need to come together, which is more on the weather time scale. We know that these types of weather patterns do occur quite frequently in the summer,” she said.

Fedaeff said New Zealand has reached 40C on only three days in its history, whereas such high temperatures are significantly more common across the ditch and in Europe.

A fire at Tangoio in January 2020 during a devastating heatwave and bushfires in Australia. The hottest temperature in Hawke’s Bay that month was 36.3C in Wairoa.

Hot start for 2026

For the first few months of this year, above-average temperatures will be experienced particularly in the north and west of the North Island.

The Earth Sciences seasonal climate outlook for January to March also indicated above-average rainfall for the north and east of the North Island, and below-average rainfall for the west of the South Island.

Fedaeff said that at the start of the year, a weak La Nina will be at play over the country.

“That means we get more northerly and northeasterly winds, so more weather from the tropics, which is a warm place.”

She said the factors that contribute or have historically contributed to NZ having a hot year include warm seas.

“Marine heat wave conditions, which are in play now, and they don’t turn off as quickly as air temperatures do,” she said.

Fedaeff said our temperatures are also impacted by our warming climate.

“We already have this massive boost from climate change. That means that we’re starting off on a warmer note just because we’ve loaded that dice already,” she said.

The hottest temperatures are expected in Hawke’s Bay on Sunday, with 37C forecast for Hastings and 35C for Napier. Photo / Michael Craig

This comes after 2025 was named as the country’s fourth-hottest year on record, according to Earth Sciences’ annual climate report.

The report found that most regions were hotter than average by between 0.51 and 1.2C, but parts of Northland and Bay of Plenty were significantly hotter, by more than 1.2C.

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