Flash flooding possible as heavy rain descends on upper North Island

Heavy rain across the top of the country could cause flash flooding and make driving difficult, so anyone planning to go out should do so now “before things get worse”, a MetService meteorologist says.

“There’s a possibility of some flash flooding since we are expecting some significant accumulation … something like 70 to 100 millimetres of rain in those areas [and] ... there’s a possibility of some localised downpours which might result in surface flooding, even difficulty in driving in those conditions", meteorologist Samkelo Magwela said.

“The rain will start being more persistent from early afternoon or late morning, but in terms of downpours, it will be just in those localised areas. So it won’t be heavy all the time ... if anybody is planning to go out, I think it’s better to rush now before things get worse.”

Heavy rain warnings have this morning been upgraded to Orange level for much of the top of the country, as a “big swirling mass of rain” descends on the upper North Island.

Auckland, including Great Barrier Island, is under a 17-hour heavy rain warning from 9am today, with up to 100mm forecast and “possibly more in localised downpours”, MetService said.

“Peak rates of 15 to 25 mm/h, but possible 25 to 40 mm/hr in downpours mainly from this evening.”

Those in Coromandel Peninsula, Bay of Plenty and Gisborne/Tairawhiti north of Ruatoria have also been warned to expect heavy rain over a 17-hour period from later this morning until early tomorrow morning.

A heavy rain warning already in place for Northland continues to late tonight, MetService said.

Those areas have been told to expect up to 100mm of rain, possibly more in localised areas, with areas east of Whakatāne likely to be the wettest spots in Bay of Plenty.

A heavy rain watch for Waikato north of Hamilton runs from noon today until early tomorrow morning.

Orange heavy rain warnings across the upper North Island Saturday August 29. 

And in the deep south forecast strong winds have prompted MetService to issue a watch for southern areas of Southland and Clutha from 9am tomorrow to noon Monday.

A combination of weather systems is behind the wet weekend.

MetService meteorologist Katie Lyons said “some complex weather” was expected this weekend up north, with the front that caused severe conditions in the South Island this week moving up the country.

“We’ve got a low that’s sitting north of Northland and that’s got a couple of features, a couple of rain bands within it - one of which was the front that we saw move over the South Island [on Thursday] and is making its way on to the lower North Island now.

“The other rain band that is associated with this low is approaching from the north … and these two rain bands actually kind of merge over the North Island and create a big swirling mass of rain over the upper North Island.”

MetService rain radar showing heavy rain across the upper North Island at 6pm on Saturday August 29 2026. 

The rain bands are set to move on in the early hours of Sunday, leading to more settled weather for the North Island for the rest of the weekend, Lyons said. 

“We’ve got some showers in the lower north on Sunday but, overall, it’s not too bad.” 

The weekend brings a welcome reprieve for parts of the South Island that have been battered by days of heavy snow and rain, which has caused flooding, slips and road closures. 

“For the most part that wintry blast is really done and I guess we’re looking at more spring-like weather this weekend over the South Island. 

“Those in northern Otago up through Canterbury and Marlborough will have a pretty nice weekend overall, albeit a bit windy perhaps.” 

Temperatures are set to be slightly warmer than average this weekend, with a few places on the east coast of the North Island cracking the 20s as spring approaches.

It’ll be 21C and partly cloudy in Napier tomorrow, and the rain should clear early in Gisborne, where a high of 20C is forecast.