Thunderstorms are forecast across much of the South Island and lower North, with warnings of heavy rain — up to 20mm an hour — and marble-sized hail.
Meanwhile, Aucklanders have survived the first humid sleep of the season, with temperatures in the high teens persisting overnight.
The rain that affected many central and western areas over the weekend will persist today, with the low-pressure system creeping over the eastern areas throughout the morning.
MetService meteorologist Oscar Shiviti said the weather would be unsettled today, with rain mostly affecting the South Island, where areas were already drenched over the weekend, and the central North Island from this afternoon.
A heavy rain warning is in place for the headwaters of Canterbury lakes and rivers south of the Rangitata River until midday.
🔔📡Morning Rain Radar Update!!
— MetService (@MetService) October 12, 2025
🌧️Rain and showers continued overnight, with heavier falls over the South Island.
💧In the past 12 hours (7pm–7am):
- Franz Josef: 26.2 mm
- Mt Cook: 28.4 mm
- Arthur’s Pass: 20.2 mm
☔️Keep your rain gear handy as rainy conditions are set to… pic.twitter.com/17yjkGXm53
Earlier, only a watch was placed over Tongariro National Park, but it has since been upgraded to a warning.
A heavy rain watch is in place for Waitomo, Taumarunui, Taupō, and Taihape northwest of Waiōuru, for 20 hours from 4pm.
The same watch is also in place for Taranaki about and north of Taranaki Maunga and the Tararua Range from midday.
Thunderstorms are possible, bringing marble-sized hail, heavy rain, and strong wind gusts.
MetService reported a change to southwesterlies brings a moderate risk of thunderstorms to parts of South Canterbury and Otago this afternoon and evening.
The risk of residents seeing the storms decreases further up the country; however, MetService reported that anywhere from northwest Tasman down to the glaciers is in the firing line for heavy rain with intensities of 10 to 20mm/h and strong wind gusts.
Shiviti said at 3am this morning that temperatures in Auckland were still soaring at 17C, well above average. For this time of year, the average high is 18C.
The temperature was the same at 7am in Tauranga and Gisborne, where residents also suffered a humid night.
Spring often brings wind. But this spring is next level.
— NIWA Weather (@NiwaWeather) October 12, 2025
Why the relentless wind? We look to Antarctica🐧.
Air pressure has been unusually high 🔴 over the polar region, forcing lower than normal pressure 🔵 north, causing a large pressure gradient over NZ, which drives wind. pic.twitter.com/DX5KyKMsDQ
Napier was slightly higher, sitting at 18C at 7am.
MetService forecaster Alannah Burrows said the high temperatures affecting the North Island would continue today.
“In Auckland, we’re looking at highs of 22C, which is 4C higher than average for this time of year.
“Napier will see another warm day on 26C. Even on the east coast of the South Island, we’ve got 21C for Christchurch.”
According to MetService forecasts, Kaitāia and Hamilton are forecast to reach a high of 20C, while Whangārei will reach 22C.
A heavy rain warning is in place for the headwaters of Canterbury lakes and rivers south of the Rangitata River until 12pm, with up to 120mm worth of rain expected.
However, this evening, a series of low-pressure systems will begin to reduce temperatures in the South Island.
“As we come into Tuesday, the low-pressure system that has come in for the South Island is going to start pushing its way to central New Zealand and across the North Island.
“It does look like quite a rainy day for the North Island through Tuesday.”
On Wednesday morning, Burrows said a “transient ridge of high pressure” would move across New Zealand.
“It may be a bit more settled compared to what we have seen, before we get our next frontal band pushing on to the South Island.”
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