Parts of Auckland and Northland are due for another drenching today after a night of wild weather that turned fatal for two people.
Two hikers were swept to their deaths in the Waitakere Ranges just after 5pm, apparently while trying to cross a swollen river near Cascade Falls.
Police have not confirmed whether a third person reported missing has been accounted for.
Around 100 people were evacuated from houses in Piha and a group of 20 people were also trapped for three hours after a river near Kitekite Falls flooded, stopping them from returning to their cars.
More heavy downpours are possible today in Auckland and Northland as a narrow rain band hovers over the upper North Island. Isolated thunderstorms are also possible.
MetService meteorologist April Clark said the same tightly wrapped front is still hovering from Auckland to Northland, south of Kerikeri.
Isolated downpours and possible thunderstorms were likely all day for Northland, while
the worst weather in Auckland would not start until after lunch.
Rainfall could reach 40mm an hour in spots, Clark said, meaning there could be a repeat of yesterday's heavy downpours although they would not be as widespread.
An Auckland Council weather station in the Waitakere Ranges recorded a "huge" 55mm between 4pm and 6pm last night, while between 5pm and 6pm 27.5mm of rain hit Piha, she said.
It was unclear where the worst weather would hit, she said. More updates are due at 10am.
MetService has issued a severe weather watch for Northland.
WeatherWatch.co.nz said the rest of the North Island would be mainly settled, with light winds and temperatures in the low 20s.
Parts of the South Island would be more than 10C hotter than yesterday as a westerly airflow returns.
A few downpours are possible on the West Coast, and Southland would see rain later in the day with a possible dusting of snow for Queenstown's ski fields today. Temperatures would range from 18C to 27C in the warmer east, WeatherWatch said.
Whangarei Downpours, thunderstorms possible. Easterlies. High 23C, Low 17C
Auckland Rain, possible thunder afternoon. SE winds tend NE. 23C, 17C
Hamilton Chance of afternoon showers. Light winds. 24C, 14C
Tauranga Chance of afternoon showers. Light winds. 23C, 17C
Napier Fine, NE winds in afternoon. 23C, 14C
Wellington Fine, night cloud. NE strengthening. 21C, 17C
Christchurch Chance of afternoon showers. NE turn NW. 27C, 14C
Dunedin Mainly fine, brief afternoon showers. NE. 21C, 12C
Queenstown High cloud, chance showers. Westerlies. 20C, 10C