Last month was New Zealand's 5th warmest April on record, Photo: RNZ / Rebekah Parsons-King
Last month was New Zealand's 5th warmest April on record, according to the National Institute of Water and Atmospheric Research (NIWA).
Temperatures were well above average (>1.20°C above average) in every region of the country last month in NIWA's latest Climate Summary.
NIWA's seven station temperature series, which measure data across the country, show the nationwide average temperature in April 2025 was 15.2°C.
This was 1.8°C above the average temperatures in April between 1991 and 2020.
NIWA meteorologist Seth Carrier said the month had some eye-catching data recordings.
"The most notable thing for April was that it was the fifth warmest April on record, and those records go back to the year 1909," Carrier said.
"So, fifth warmest in over a hundred years is definitely notable, and the reason for that warm temperature, those warm temperatures, was that we had a lot of air flows from the north during the month of April."
Twenty-two locations had their warmest April on record, while a further 52 locations observed near-record high April mean temperatures.
Auckland, Tauranga, Hamilton, Wellington and Dunedin had near-record high April temperatures, with Christchurch being above average.
"Basically, we had low pressure to the west of the country and high pressure to the east of the country, and those two things are kind of working like cogs, dragging warm air out of the subtropics south towards New Zealand," Carrier said.
"We had a lot of northerly winds. Northerly winds are definitely a warm wind direction, and with more northerly winds than normal, that definitely led to those warmer temperatures for the month of April."
Rainfall in April was above normal (120 - 149 percent of normal) or well above normal (>149 percent of normal) for Northland, Auckland, Coromandel, Bay of Plenty, much of Taranaki, western Wellington, Tasman, Nelson, northern West Coast, Marlborough, eastern Canterbury, and parts of Central Otago.
In contrast, April's rainfall was considered below normal (50 - 79 percent of normal) or well below normal (<50 percent of normal) rainfall in Gisborne, Hawke's Bay, Whanganui, Wairarapa, Dunedin, South Otago and southeastern Southland.
Rainfall was well above normal in Auckland, Tauranga, and Christchurch, with Auckland observing its fourth-wettest April on record.
SH10 in Northland during Cyclone Tam in April, 2025. Photo: RNZ / Peter de Graaf
Six locations observed their wettest April on record with Kaitaia New Zealand's wettest location compared to normal.
The Northland town received 420mm of rainfall (437 percent of normal for April), which was its wettest April since records began in 1948.
New Zealand's driest location compared to normal was Wairoa, Hawke's Bay, which received 47mm of rain during April (36 percent of its April normal).
Carrier said more heavy rain events could be in store for the coming winter months and potentially impact the snow season.
"As we go through May, June, July, towards the winter season, I do think that we could see more rainmakers coming out of the north," he said.
"So the chance for perhaps periodic heavy rainfall events, especially as we get probably into that July and August time frame, I think that's probably going to be the best chance for heavier rainfall.
Carrier said if the country is going to see more northerly winds, it means temperatures could remain warmer than average, at least at times, as we go into the winter season.
"If we do have more of those northerly winds, and that does tend to bring the warmer temperatures, unfortunately, it could put a bit of a damper on the snow season, including in the South Islands. We don't explicitly forecast snow," he said.
"But if we are getting more northerly winds, that's not a great wind direction in order to get the cold temperatures that we need to form that snow in the South Islands.
"So, at the current lead time, snowfall for the coming season, the coming winter season, might be a little bit hard to come by to get substantial snowfall. That's definitely one thing on the radar."
April weather highlights:
- The highest April temperature was 29.7°C, observed at Orari, South Canterbury on 4 April
- The lowest April temperature was -3.6°C, observed at Ranfurly, Central Otago on 24 April
- The highest 1-day rainfall was 290 mm, recorded at Tākaka, Golden Bay on 3 April
- The highest wind gust was 156 km/h, observed at Cape Reinga, Northland on 17 April
- Of the six main centres in April 2025, Auckland was the warmest, Christchurch was the coolest, Dunedin was the driest and sunniest, and Tauranga was the wettest and least sunny
- The sunniest four regions so far in 2025 are Taranaki (1075 hours), Bay of Plenty (996 hours), Auckland (990 hours), and Central Otago (987 hours).
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