An intense storm with unusually strong winds caused damage and disruption across large parts of Aotearoa/New Zealand from 21 October to 27 October 2025. High winds exacerbated fires and damaged buildings, as well as causing power cuts and water shortages. One person was killed in Wellington by a falling branch. Flows in the Waimakariri and Rakaia rivers in Canterbury exceeded their estimated 1-in-10 year flood levels. The West Coast Region became completely isolated by road following closures of the three mountain passes linking the West Coast to the rest of the South Island. There was extensive damage in the Otago and Southland regions with loss of electricity supply to 65,000 properties and 6,000 still not reconnected one week later.

States of emergency were declared in Canterbury, Southland, and the Clutha District. By 24 October, the state of emergency had been lifted for much of Canterbury except the Kaikoura District. By 7 November, the states of emergency in the Clutha District and Southland had been lifted.

Meteorology

The buildup to this event started with a large mass of very warm air developing into a high pressure zone over Australia and then moving into the Tasman Sea and on towards New Zealand early in the week. Over the same period, a mass of cold air that sits above Antarctica over winter, known as the Polar vortex, started to break down and fade. This weakening system sent surges of cold air northwards and into the Southern Ocean. The situation leading to the storm was a deep low pressure system passing just south of New Zealand, with an active front extending further south, together with a large high pressure system stationary to the northeast of New Zealand. The difference in pressure over a distance of around between 1024 hPa at the centre of the high, and around 950 hPa at the centre of the low, created a steep pressure gradient between the two systems, leading to high wind speeds. The intensity of the storm was increased by the difference in temperatures of air masses to the north and south of the country.

On 23 October, MetService issued red warnings for severe wind for Wellington and Christchurch, and forecast that gusts might reach . In the Wellington region, by 8:00am peak wind gusts of were recorded at Mount Kaukau, with at the Remutaka Summit, and in the Wellington suburb of Kelburn. Later in the morning gusts of were recorded at Mount Kaukau. In the South Island, wind speeds of were recorded in Methven, in mid-Canterbury, and up to at Sugarloaf above Christchurch.

A further storm was forecast for Labour Day, with severe wind and heavy rain warnings issued across much of the country. A heavy snow warning was issued for the Queenstown Lakes District, Central Otago and the Canterbury High Country.

Hawke's Bay and Lower North Island On the morning of 21 October, MetService issued orange strong wind warnings for the Hawke's Bay and the lower North Island. Strong northwesterly gales toppled vehicles travelling on State Highway 2 and State Highway 50, damaged and destroyed roofs, fences and in Dannevirke and Norsewood, and caused power outages to nearly 1,000 properties in the Hastings District and the Central Hawke's Bay District.

On 21 October about five vegetation fires broke out in the Hawke's Bay. The largest, in Pōrangahau, covered an estimated area of in the evening of that day.

Wellington Region On 21 October a man died after being hit by a falling branch in Mount Victoria in Wellington. The Wellington City Council "strongly urged" people to keep away from the city's parks and reserves due to the risk of falling trees or branches. The wildlife sanctuary Zealandia was closed. Several buildings were damaged across the region as well.

From 8am on 23 October, a red wind warning was in place for Wellington and parts of the Wairarapa. All of the city council's facilities were closed, including libraries and Wellington Zoo. Victoria University of Wellington was closed and in-person examinations were postponed, and a New Zealand Symphony Orchestra concert was cancelled. The council's Emergency Operations Centre was activated.

Canterbury and the Upper South Island On 20 October, strong gale force winds caused a large truck's trailer to roll over, blocking multiple lanes on State Highway 8 between Lake Tekapo and Lake Pukaki. Gusty winds exceeding 140km/h were also recorded in the Mackenzie Country. MetService also forecast strong winds in Canterbury High Country and the foothills of the Canterbury Plains.

On 21 October, several fires started in the northern Kaikōura District. While it is not known what caused the fires, the winds caused them to spread. A peak of 50 fire appliances and 120 personnel were fighting the fires. The fires caused several highways around Kaikōura including State Highway 1 to temporarily close. By the early afternoon 22 October 14 rural buildings had burnt down, including five homes. An emergency operations centre was set up in the Kaikōura Fire Station.

On 23 October, several parks were closed in Christchurch, including but not limited to the Christchurch Botanic Gardens and Mona Vale. A lightning strike knocked out Methven's water treatment plant. The closure of State Highway 7 due to fallen trees caused difficulty for firefighters to reach a fire in Hanmer Springs on 23 October.

In response to the rising flood levels in the Waimakariri River, at 6:00pm on 23 October, the Waimakariri District Council issued a voluntary evacuation notice for residents of Kairaki, a small coastal settlement to the north of the Waimakariri River mouth, because of a predicted risk to the Kairaki Beach stopbank at around 11:00pm that evening. The notice also advised residents of The Pines Beach to prepare for the possibility of requiring a prompt evacuation. The trigger for the voluntary evacuation notice was a predicted flow of 2,500 cumecs. The peak flow recorded was 2,700 cumecs, significantly exceeding the 1-in-10 year flood estimate of 2,270 cumecs, but the time of peak flow coincided with low tide. The evacuation notices were withdrawn by 9:30am on 24 October.

The flood levels in the Rakaia River as measured at Fighting Hill reached 4,975 cumecs, exceeding the 1-in-10 year flood estimate of 4,040 cumecs. Environment Canterbury issued a voluntary evacuation advisory for areas adjacent to the river downstream of State Highway 1, including the South and North Rakaia Huts. The advisory was lifted by 9:00am on 24 October.

West Coast The West Coast had previously suffering heavy rains and flooding when the storms came through further dampening recovery efforts. On 23 October a lightning strike knocked out Greymouth's water treatment plant, causing water shortages in Greymouth and surrounding communities. Schools were closed.

The entire West Coast Region was without power for four hours on the morning of 23 October. The West Coast also became isolated by road after slips, debris and flooding caused closures of the Lewis Pass, Arthurs Pass and Haast Pass routes between the West Coast and the rest of the South Island. State Highway 6 was also closed between Murchison and Kawatiri Junction.

Otago

Strong winds on 21 October collapsed a shed in Mosgiel and cut power throughout the Dunedin area. High winds on 23 October, gusting up to 170 km/h at Taiaroa Head, caused further widespread damage.

Following the high winds on 23 October, over 100 slates were ripped off the roof of Knox Church, and roof damage was also reported at Otago Badminton Centre, Dunedin Ice Stadium, Forbury Park, Forsyth Barr Stadium and Dunedin railway station. Two trees next to the Hocken Collections in Dunedin were toppled during the 23 October winds, following two trees blown over on the 20th, fracturing a water main. The trees formed part of the Anzac Avenue memorial to World War I soldiers.

Southland

Riverton and Invercargill were also affected by wind on 21 October, with significant damage at Ascot Park Raceway. Invercargill and Gore were hit by strong north-westerly winds around midday on 23 October, resulting in over 100 FENZ callouts in Invercargill and damage throughout the Southland region.

Treefalls, slips, and flood-damage closed the Milford Road.

Damage to the distribution network in Southland and Otago left 25,000 homes without power, with some expected to be without power for a week. According to the Otago Daily Times, an estimated total of 65,000 properties in Otago and Southland lost power during the storm on 23 October. As of 30 October, there were still 6,000 properties in Clutha and Southland that had not yet been reconnected.

22 cellphone towers in Southland were also knocked out by wind damage on 23 October, disrupted phone services throughout the region. On 24 October, Southland Federated Farmers President Jason Herrick reported that power outages had disrupted the local dairy industry. While some dairy farmers had emergency power generators, there was a limited supply. Federated Farmers also confirmed it was liaising with a generator supplier, the central government and Member of Parliament for Southland Joseph Mooney to obtain spare generators from the North Island.

Impact

As of 28 October FMG Insurance has received over $10million worth of insurance claims, about half of which were from Southland and Otago.

Agriculture On 25 October, the Otago Regional Council (ORC) allowed farmers with full effluent pools and who needed to irrigate wet soil to release them into paddocks on the condition that they did not flow into title drains or waterways. The ORC also allowed dairy farmers to discharge milk into effluent storage facilities or onto land on the condition that it did not contaminate drains or waterways. The Council also suspended dairy farm inspections until 3 November.

Power disruptions caused several farmers to dump milk due to the inability to refrigerate milk. On 27 October, RNZ reported that 200 dairy farms across Southland were relying on power generators to milk their cows. Farmers shared power generators among their neighbours. Following the windstorm on 23 October, the Rural Support Trust focused on animal welfare by allocating generators to dairy farms. The Trust also established five welfare centres to provide moral support to farmers.

On 3 November, Rural Women NZ South Island national board member Sharron Davie-Martin said that the Southland region faced a "long road to recovery." Several farms faced damage including the destruction of milking sheds, hay barns and staff houses. The charity activated its Adverse Events Relief Fund to provide support to farmers affected by the storms including food supplies, counselling and organising barbeques.

Economic impact By 29 October, the New Zealand insurance companies AMI Insurance, State Insurance and NZI had received over 3,300 claims covering home, contents, motor and commercial policies. The majority of these claims were linked to wind damage in Southland, Otago, Canterbury and Wellington including broken windows, damaged roofs and fallen trees. According to Insurance Business New Zealand, Southland accounted for 1,129 claims, Otago for 615, Canterbury for 481, and Wellington for 504, with other regions comprising 566 claims. Notable insurance claims included eight claims linked to the Whangarei Hospital fire and four claims connected to the Kaikoura fire.

By 20 November, 7,000 insurance claims for storm-related damaged had been filed in the South Island. FMG Insurance received over 3,000 insurance claims (1,500 in Southland and 700 in Otago) related to wind damage, amounting to about NZ$28 million. On 22 November, the Invercargill City Council reported that it had sustained a total of $2.39 million worth of damage to infrastructure and property in Invercargill including parks, reserves, elderly housing, roads, fallen trees, damaged cars and aerials.