Some residents in Hawke's Bay have been forced to evacuate their homes as the heavy rain continues to lash the region.
Residents in Te Karaka, inland from Gisborne, are being asked to evacuate by Tairāwhiti Civil Defence as the Waipaoa River rises.
Tairāwhiti Civil Defence said the river is getting close to 7m.
"We will update people as the situation changes. Anyone feeling unsafe or in a low lying area should self-evacuate otherwise be prepared to leave should the river level reach 7.5m. Take your pets and food supply for you, your whānau and animals," Tairāwhiti Civil Defence said in a Facebook post on Sunday morning.
The Te Karaka Area School has been opened for anyone who needs somewhere to go and is the headquarters for iwi response team Mahaki Tiaki Tangata.
It comes as MetService said a low-pressure system, which is northeast of East Cape, is bringing a strong and humid south-to-southeast flow and heavy rain to Hawke's Bay and Gisborne.
This has seen MetService extend its orange heavy rain warning for the Gisborne and the Wairoa District of Hawke's Bay until 11am on Sunday morning.
The forecasting agency said the area should expect a further 30 to 40mm of rain to fall at peak rates of 15mm/h in addition to what has already fallen.
"The rain may ease for a time between 7am-9am then increase again before easing significantly late morning."
MetService warns the rain could be heavy and cause surface flooding.
"Heavy rain may cause streams and rivers to rise rapidly. Surface flooding and slips are also possible and driving conditions may be hazardous," MetService said.
Allan Baillie from MetService told Newshub the rain hitting the east coast of the North Island is a "significant rain event".
"There's just one more band of rain that's going to pass through in the next three or four hours and it's on top of some pretty substantial falls over the last 48 hours, a lot of places have had over 150mm already in that area," Baillie said.
He told Newshub he wouldn't be surprised to see more flooding in the area under the orange heavy rain warning.
"The rainfall rates are not extreme... but it's all just going to run off because the ground is already sodden, so everything is just going to flow straight to the rivers," he said.
"So any river that's already high is going to keep rising gradually until the rain stops."
But there is good news for many places around the country, with many in for a sunny Sunday.
"The rest of the country is pretty fine today. Mostly cloudy in the east coast of the North Island. The South Island is very clear apart from some low cloud about Southland, which hopefully will burn off this morning," Baillie told Newshub.
"There is some morning cloud about Whanganui and Taranaki but apart from that it's a pretty fine day for most people."
Heavy Rain Warning – Orange
Impact: Heavy rain may cause streams and rivers to rise rapidly. Surface flooding and slips are also possible and driving conditions may be hazardous.
Area: Tairawhiti/Gisborne and the Wairoa District of Hawke's Bay
Period: 5hrs from 6am - 11am Sun, 26 Nov
Forecast: Expect a further 30 to 40 mm of rain to accumulate in addition to what has already fallen. Peak rates of 8 to 15 mm/h. Note: Warning extended by a few hours. The rain may ease for a time between 7am-9am then increase again before easing significantly late morning.
