NIWA has released its Annual Climate Summary for 2024, providing an insight into last year’s weather, including the sunniest, wettest and warmest places in New Zealand.
Here’s a look at some of the key findings.
Temperatures
2024 was the 10th warmest since records began – not as hot as 2023, but still a warm year. The nationwide average temperature was 13.25C, 0.51C above the 1991-2020 annual average.
Temperatures were above average for much of Northland, northern Waikato, Bay of Plenty, coastal Hawke’s Bay, southern Taranaki, Whanganui, eastern and southern Wairarapa, Tasman, inland northern Canterbury, Banks Peninsula, and eastern Otago. They were near average elsewhere.
Only two months nationally, March and May, were below average. These were the second and third times since 2017 that New Zealand saw below-average temperatures.
The spot with the highest average temperature was Leigh, at 17.3C, followed by Kaitāia at 16.8C, and Whangaparāoa at 16.5°C. The highest air temperature of the year was 37.0C in Hanmer Forest, followed by 36.9C at Waipara West, and 36.5°C at Waiau.
The lowest air temperature recorded in 2024 was -11.8C at Lake Tekapo on August 3. This was followed by -11.1C at Mt Cook Airport on August 3 and 4 and -10.9C at Lake Tekapo on August 4.
NIWA principal scientist Chris Brandolino told 1News it was part of a continuing trend of warmer weather.
“Since 2013, out of the 10 warmest years in New Zealand, and this goes back to 1909, eight of them have occurred since 2013.”
While 2024 was not as hot as in recent years, Brandolino stressed that it was part of a trend that was “not good”.
“That trend is for increasing temperatures year on end,” he said.
“Each year continues to increase, and that is congruent and aligned with what we’re seeing globally. We’re seeing warm temperatures globally, Australia announced its second warmest year on record.”
He said that later this week, when Copernicus, ECMWF and NASA give their annual global climate summary, it’s expected to be the hottest year on record.
“Either way you slice it, whether it’s the first, the second or the 10th warmest year on record, it’s part of a larger trend that is not the trend we want to be on.”
Rain heavy for some
Much of the country experienced mixed rainfall, with some regions experiencing more than average rainfall while others saw less.
Much of eastern and northern Canterbury, Tasman, Wairarapa, Bay of Plenty, the Coromandel Peninsula, and Northland experienced below-normal rainfall (50% to 79% of the annual normal).
The lowest rainfall totals for 2024 were seen in Alexandra with 354 mm, Bromley (Christchurch) with 354 mm, and Riccarton (Christchurch) with 374 mm.
It was above normal (120% to 149% of the annual normal) for Western parts of Otago and inland and western parts of Southland. The wettest locations in New Zealand were Cropp River at Waterfall (West Coast, 975 metres above sea level) with 11,503mm, Tuke River at Tuke Hut (West Coast, 975 metres above sea level) with 11,256mm, and Cropp River at Cropp Hut (West Coast, 860 metres above sea level) with 10,191mm.
Six locations in the South Island experienced near-record one-day rainfall totals during the year. On October 3, Dunedin experienced 131mm of rain, equivalent to 18% of its average annual total.
Overall, Brandolino said, 2024 was not as wet as 2023, which saw several regions experience extreme rainfall events.
“2024 certainly still had its big rainfall events, but not to the extent of 2023,” he said.
These were seen in the upper and central parts of the South Island during April; Gisborne and Hawke’s Bay during June, where 400 properties were impacted by flooding; Otago during October, where heavy rain caused flooding that red and yellow-stickered several homes; “persistently wet conditions” in the five weeks before October in Southland and Clutha; and flooding and slips in the Southern Ward of Westland.
The highest confirmed wind gust was 198km/h at Cape Turnagain on September 20.
What regions got the most sun?
It wasn’t all rain and clouds in 2024, with many parts of the country getting a fair bit of sunshine.
Bleheim experienced the country’s highest annual sunshine total for the year, with a total of 2769 hours.
This was followed by the wider Nelson region, which saw 2760 hours of sunshine recorded at Richmond, Bay of Plenty with 2734 recorded at Tauranga, and Tasman with 2665 recorded at Tākaka.
What was behind 2024’s weather trends
Brandolino described a “fluttering” El Nino event during Summer and Autumn, which caused westerly and southwesterly winds. These brought “some pretty dry conditions” for eastern and northern parts of New Zealand.
This was felt in Dargaville and Whitianga, which both observed their driest year on record.
Another factor in the year’s weather was sea surface temperatures, which were “unusually cool” between February and May. Temperatures fell as low as 0.9C below average off the west of the South Island.
Brandolino said that because New Zealand was an island nation, air and sea temperatures were “joined at the hip”.
“It’s no coincidence that in March and in May those two months were colder than average from a national perspective.
“When ocean temperatures are unusually warm it certainly increases the odds for warmer than average air temperatures, but it also throws out more water vapour. Warm ocean temperatures increase the water vapour, and water vapour is fuel for rain.”
Emissions continue to rise
In 2024, NIWA’s daily carbon dioxide measurements continued to rise to 420 parts per million (ppm). In 2015, NIWA recorded less than 400ppm.
Brandolino said this was another factor behind the increasing temperature.
“When you increase the temperature, not only are you more likely to have extremes, so we’re talking extreme heat, but also that affects how precipitation occurs.
“You’re more likely to have extreme rainfall on both ends of the spectrum.”
He said that in the coming decades, climate change is expected to cause more extreme weather events, such as wind, rain, drought, and flooding.
“What climate change does is make those things more likely to occur, the frequency higher, and it makes them more extreme.”
He described climate change as a “steroid” for extreme weather.
How does 2025 look?
Brandolino said that while he could not give a one-year weather outlook, the first three months will see above-average temperatures for the North Island.
He said there may be individual days and weeks that don’t match that outlook, but “our expectation is that for the North Island, the theme will be above-average temperatures.”
For the South Island, Brandolino said: “If there are areas that are not warmer than average, it will be there”.
He said there would be “equal chances” for temperatures to be average or above average.
