An intense storm with unusually strong winds caused damage and disruption across large parts of Aotearoa/New Zealand from 21 October 2025 to 27 October 2025. High winds exacerbated fires and damaged buildings,as well as causing power cuts and water shortages.[1][2] One person was killed in Wellington by a falling branch.[3] 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.
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 stationery to the northeast of New Zealand. The difference in pressure over a distance of around 2,800km (1,700mi) between 1024hPa at the centre of the high,and around 950hPa 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.[1][2]
On 23 October,MetService issued red warnings for severe wind for Wellington and Christchurch,and forecast that gusts might reach 150km/h (93mph). In the Wellington region,by 8:00am peak wind gusts of 142km/h (88mph) were recorded at Mount Kaukau,with 139km/h (86mph) at the Remutaka Summit,and 109km/h (68mph) in the Wellington suburb of Kelburn. Later in the morning gusts of 155km/h (96mph) were recorded at Mount Kaukau. In the South Island,wind speeds of 141km/h (88mph) were recorded in Methven,in mid-Canterbury,and up to 137km/h (85mph) at Sugarloaf above Christchurch.[7]
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.[8][9][10]
On 21 October about five vegetation fires broke out in the Hawke's Bay. The largest,in Pōrangahau,covered an estimated area of 30 hectares (74 acres) in the evening of that day.[12]
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.[3] 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.[13] 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.[14]
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.[15]
On 21 October,several fires started in the northern Kaikōura District.[16] 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.[17] By the early afternoon 22 October 14 rural buildings had burnt down,including five homes.[18] An emergency operations centre was set up in the Kaikōura Fire Station.[16]
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.[21] The trigger for the voluntary evacuation notice was a predicted flow of 2,500cumecs. The peak flow recorded was 2,700cumecs,significantly exceeding the 1-in-10 year flood estimate of 2,270cumecs,[22] but the time of peak flow coincided with low tide. The evacuation notices were withdrawn by 9:30am on 24 October.[21]
The flood levels in the Rakaia River as measured at Fighting Hill reached 4,975cumecs,exceeding the 1-in-10 year flood estimate of 4,040cumecs.[23] 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.[24] The advisory was lifted by 9:00am on 24 October.
West Coast
On 23 October a lightning strike knocked out Greymouth's water treatment plant,causing water shortages in Greymouth and surrounding communities.[25] Schools were closed.[26]
The entire West Coast Region was without power for four hours on the morning of 23 October.[27] 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.[28]
Strong winds on 21 October collapsed a shed in Mosgiel and cut power throughout the Dunedin area.[29] High winds on 23 October,gusting up to 170 km/h at Taiaroa Head,caused further widespread damage.[30]
Riverton and Invercargill were also affected by wind on 21 October,with significant damage at Ascot Park Raceway.[29] 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.[33]
Treefalls,slips,and flood-damage closed the Milford Road.[34]
Damage to the distribution network in Southland and Otago left 25,000 homes without power,[35] with some expected to be without power for a week.[36] 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.[37] As of 30 October,there were still 6,000 properties in Clutha and Southland that had not yet been reconnected.[38]
22 cellphone towers in Southland were also knocked out by wind damage on 23 October,disrupted phone services throughout the region.[39]
On 24 October,the Invercargill City Council,Southland District Council and the power company PowerNet confirmed they were working to reopen roads and restore power utilities and lines.[40] That same day,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 SouthlandJoseph Mooney to obtain spare generators from the North Island.[39]
Impact
A fallen branch hanging on a powerline in Saint Clair,Dunedin
As of 28 October FMG Insurance has received over $10million worth of insurance claims,about half of which were from Southland and Otago.[41]
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.[42]
Power disruptions caused several farmers to dump milk due to the inability to refrigerate milk.[43][44] 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.[43]
Energy and power outages
On 21 October,strong winds caused widespread power outages and fallen trees in Wairarapa. 10,000 properties lost power. Metlink also closed the route 200 bus service and all school buses due to the turbulent weather.[45]
Storm damage on 23 October cut power to an estimated 66,000 properties across Otago and Southland;with PowerNet estimating that 50,000 properties in Southland had lost power while Aurora Energy estimating that 16,000 properties in Otago had lost power.[37] By 25 October,power had been restored to 10,000 homes in Southland while 15,000 homes remained without power.[48] By the morning of 27 October,PowerNet estimated there were still 9,500 customers without power.[37] By the evening of 28 October an estimated 5,500 properties in the South Island were without power.[41]
In response to misinformation about fuel scarcity,Environment Management Southland (EMS) clarified on 26 October that the Southland region had sufficient supplies of fuel. As of 25 October,five percent of the nearly 200 retail fuel sites in Southland and Otago had no power.[49] By 26 October,PowerNet has restore power to about 40,500 customers in Southland,with 9,500 customers remaining without power.[49] In addition,130 cellphone towers across Otago and Southland had been damaged by the windstorm.[49] By 27 October,EMS was moving 31 power generators around the region to support critical infrastructure,dairy sheds and community hubs. Fire and Emergency New Zealand also shared some power generators.[43]
Transport
On 21 October,Air New Zealand postponed or cancelled all of its Wellington flights until 1pm.[50] On 23 October,ninety per cent of Air New Zealand's flights until 10am were cancelled and all of Jetstar's Christchurch flights until 4pm were cancelled. At 9:30am on 23 October,Flightradar24 reported that there were only two flights taking place above the upper South Island and central and lower North Island. One DHL flight in the morning was the most tracked plane on the service in the world at one point.[51] Many Dunedin and Queenstown flights were cancelled on 23 October.[30] In total,over 200 flights on 23 October were cancelled.[52]
On 23 October,all trains in and out of Wellington from 8am to 6pm were cancelled. Replacement buses were offered for the Kāpiti and Hutt Valley Lines but not for the Johnsonville or Melling branch lines. All of the Wairarapa's bus services on the 200 route were cancelled.[14] The 23 October storm also disrupted the railway network in Otago and Southland.[37]
All three mountain passes Lewis Pass,Arthurs Pass and Haast Pass that provide road access between the West Coast and the rest of the South Island were closed by slips,debris and flooding.[28] The Remutaka Hill road linking the Hutt Valle y to the Wairapapa was also closed all day on 23 October.[53]
By 26 October,the Southland rail network was largely operational apart from the Woodlands,Longbush,Rimu Road and Steel Road railway crossings near Invercargill.[49] On 27 October over 50 Wellington flights were cancelled due to wind and several state highways in Otago were closed due to snow.[54]
Responses
At 3pm on 22 October,the Minister of Emergency Management and Recovery Mark Mitchell declared a state of local emergency for Canterbury.[4] It was lifted the following day at 5:40pm,except for Kaikōura.[55]
In the morning of 24 October,Mitchell declared a state of local emergency for Southland.[5][56] Emergency Management Southland controller Lucy Hicks said that the states of emergency were expected to continue into the following week.[37]
On 24 October,the Clutha District Council declared a state of emergency in the Clutha District.[6] Due to damage to local water networks,a boil water notice was issued for the district. The New Zealand Defence Force (NZDF) also deployed personnel in the Clutha District to conduct welfare checks.[37]
On 25 October a Royal New Zealand Air ForceC-130J Hercules was used to ferry civil defence staff and 40 portable generators to Southland.[57] These included 20 portable generators and three-trailer mounted generators,with priority being given to rural areas.[37]
On 27 October,the Government donated a total NZ$150,000 to mayoral relief funds in Southland and Clutha District to assist with post-storm damage;with Southland receiving NZ$100,000 and Clutha NZ$50,000.[58][59] In response,an Inch Clutha farmer named Donna Weir described the government's emergency relief funds as insufficient,citing the devastating economic impact of the storm on farmers including milk dumping due to a lack of refrigeration.[60]
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