Severe weather warnings and watches are in place across the country, with much of the South Island at risk of thunderstorms.
An unstable airmass is due to affect the South Island this afternoon and this evening, in particular Canterbury and Otago where a severe thunderstorm watch is in place from 2pm to 9pm, MetService says.
The areas covered include the Canterbury Plains, Canterbury High Country, Central Otago, Southern Lakes, Southland and Fiordland, while forecasters say there is also a risk the storms could become severe at 10pm.
Downpours could hit 40mm/h and might lead to flash flooding, slips and hazardous driving conditions.
Two heavy rain warnings are in place for this afternoon in the northwest of the South Island, covering the ranges of Tasman District west of Takaka, due to lift at 4pm, and Buller, due to lift at 6pm.
Up to 90 mm of rain could fall in Buller this afternoon on top of what has already fallen, while up to 70mm could fall further north in Tasman.
MetService forecaster Alanah Burrows told the Herald the weather would be different between each island.
“The North Island will have mostly cloudy periods with the odd shower,” she said.
One heavy rain watch is in place until midnight January 3 in the North Island, covering Hawke’s Bay north of Napier and Gisborne south of State Highway 2.
Heavy periods of rain are expected in this area, and thunderstorms are possible, which could lead to localised downpours of up to 40mm/h.
A ⛈️ Severe Thunderstorm Watch has been issued for the South Island and is valid between 2pm and 9pm Thursday the 1st of January 2026.
— MetService NZ (@MetService) December 31, 2025
A watch indicates elevated risk of thunderstorms, but it does not mean they will happen; we have the ingredients to cook 🍳 but might just get… pic.twitter.com/REqbfoqhkQ
“We can see some fine breaks in the afternoon. It is generally a gentle northwesterly breeze apart from Wellington, where it is going to be windy.”
Burrows said the windiest city in the world would live up to its reputation today.
“Northerlies will become strong in the morning, gusting 90km/h and then easing in the evening.”
The Auckland and the Bay of Plenty regions could be in for “quite a nice day”.
“It’s mainly fine with the odd shower here and there. As we go into the afternoon, we get some warmer temperatures.
“There is a chance we will see a shower. There is a chance it will be heavy in the east from the afternoon to the evening, but the chances of seeing them aren’t that high.”
Unsettled weather is forecast for the South Island this morning, especially in the northern and central parts.
“The showers would be easing in the west in the afternoon but remaining in the east for longer,” Burrows said.
“The remaining rain will be clearing in the afternoon for the northeast areas of the South Island, such as places like Marlborough and Nelson.”
Burrows said showers were forecast for the Canterbury region but these would ease in the evening.
However, the risk of wet weather is forecast to return for the North Island tomorrow and Burrows said a front may push across the country through the second half of the day.
“Perhaps a bit showery for the South Island on Friday as well,” she said.
“There is still going to be some wet weather across the country in the next few days before we get into Sunday, where we might see more of a settled spell into next week.”
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