Rain has started to cascade over the country as severe weather warnings take effect, with threats of flooding and slips from the intense downpours.
A MetService weather radar indicated severe thunderstorms near the Catlins State Forest Park, Clinton and Waipahi, moving southeast.
The storms are expected to affect areas including Papatowai, Owaka, Clinton and Waiwera South this evening.
MetService said storms may bring heavy rain, large hail and frequent lightning, creating a high risk of flash flooding, dangerous driving conditions, damage to property and crops, and hazards from lightning and power surges.
It advised taking shelter indoors away from windows, avoiding trees and water, moving vehicles under cover, securing loose items, clearing drains and driving with caution.
During and after the storm, MetService also advised staying alert for fallen trees and power lines and keeping away from streams and drains because of the risk of flash flooding.
The thunderstorm warning is set to be updated or lifted by 5.45pm today.
SEVERE THUNDERSTORM WARNING
— MetService NZ (@MetService) December 26, 2025
Area: Gore, Clutha and Southland
At 04:45 pm, MetService weather radar detected severe thunderstorms near CATLINS STATE FOREST PARK, CLINTON and WAIPAHI moving southeast, expected to be accompanied by very heavy rain, large hail and frequent lightning. pic.twitter.com/7ZIOJhAu4G
Areas of the eastern coastline of the South Island have also been under a severe thunderstorm watch from 1pm, with a severe thunderstorm watch remaining in place for Canterbury High Country, North Otago, Central Otago, Dunedin, Clutha and Southland.
Meanwhile, holiday hotspots including Northland, Auckland, Great Barrier Island, Coromandel Peninsula, Bay of Plenty and Rotorua lie under a severe thunderstorm watch from 2pm to 8pm.
MetService confirmed heavy rainfall has started in the Northland, Auckland and Waikato regions, with severe thunderstorm warnings still in effect.
MetService meteorologist Alana Burrows told the Herald a series of fronts will push northwards across the country, bringing yesterday’s wet weather up the South Island and across the North Island.
Heavy falls are expected to hit Northland, Taranaki and Wellington, then push up the country from late tomorrow morning and move northeastwards throughout the afternoon.
“For the North Island, we’ve got a moderate risk of thunderstorms, with heavy rain and strong wind gusts up to 90km/h through the afternoon and evening for the areas north of Waikato,” Burrows said.
Northland, Auckland and the Coromandel are most at risk of storms, with rainfalls of 25-40mm possible.
A heavy rain watch is in place for the Bay of Plenty to the east of Whakatāne from 7pm, with a risk the rainfall might upgrade to a warning near the ranges.
⛈️The top half of the North Island is in for a bit of a wild Boxing Day⛈️
— MetService NZ (@MetService) December 24, 2025
Regions Waikato northwards may see thunderstorms, with localised downpours and💨 gusts up to 90 km/h from tomorrow afternoon.
Keep an eye on the forecasts at https://t.co/Yjbq0jgaoz@AklCouncil pic.twitter.com/neuy4xBftm
The South Island won’t escape the wet weather, with bands of rain falling from Nelson down the Southern Alps, on the West Coast and Fiordland, and thunderstorms possible in the lower regions.
“We’ve got a moderate-risk area for the South Island, Fiordland up to the glaciers in Westland in the morning, and then the moderate-risk area pushes eastwards into the afternoon and evening for North Otago, Dunedin, Southland and Clutha,” Burrows said.
Southland, Clutha and Dunedin should expect some showers across the day, while the eastern ranges of the Canterbury Plains and Christchurch will have mostly fine weather.
On the weekend, the unsettled outlook will continue, with the North set to be the wetter of the two islands as a complex low-pressure system arrives from the tropics.
“That could bring quite a lot of wet weather for the North Island, a bit more settled for the South Island, but, as we push into Tuesday, some of the rain might start to affect the eastern coasts of the South Island with that low-pressure system.”
Lower temperatures could also take hold in the South Island next week, hitting below average in some places.
Looking into next week, those going away for the New Year should prepare for changeable conditions.
While the West Coast of the South Island might be having an unexpectedly fine start to 2026, the rest of the country faces erratic forecasts.
“It’s still quite uncertain, to be honest, as we head to New Year’s Eve and New Year’s Day,” Burrows said. “It just depends how that low-pressure system tracks.”