Heavy rain is forecast for Northland, the west coast of the North Island and the top of the South Island with MetService and councils monitoring the situation in some areas in case of flooding.
In the North Island, MetService has issued heavy rain warnings for Northland, Waitomo, Tongariro National Park, Taranaki and Horowhenua to Wellington.
In the South Island heavy rain warnings are in place for Tasman from Motueka westwards and Marlborough about and north of the Awatere Valley, also Nelson and Tasman south and east of Motueka.
Taranaki residents in low-lying areas urged to prepare grab bags in case evacuation needed
People living in low-lying areas of Taranaki are being urged to put together grab bags in case they need to evacuate overnight.
The region is under an orange heavy rain warning and 200 to 300mm could fall about the mountain through to 9am on Friday, and 70 to 120mm elsewhere.
That was in addition to what had already fallen.
Emergency Management said rain had been falling consistently for most of the day and river levels were running high.
On Thursday morning, it said there had been one isolated incident of a family in Egmont Village experiencing flooding on the lower floor of their home.
Group Controller Todd Velvin said flood prone areas around Waitara and Waiwhakaiho were being closely monitored.
People should make sure their phones were charged in case they were sent an Emergency Mobile Alert and should check in with friends and whānau, he said.
Velvin said asking people to evacuate was not a decision that was taken lightly and would only be done if authorities believe lives are in danger.
The level of the Waitara River in North Taranaki is being monitored closely as heavy rain continues to lash the region.
Velvin said problems occurred on the Waitara River when its eastern hill country and mountain catchments combined.
The river level at Purangi was just under 7 metres and would have to rise to about 10m before the first alarm was triggered, he said.
Nelson opens emergency accommodation
Nelson City Council is opening emergency accommodation for the homeless community on Thursday night due to severe rain warnings.
Heavy rain is set to lash the top of the South Island from tonight, and orange level rain warnings are in place for Tasman, Marlborough and Nelson from tonight into Saturday.
Nelson's council said it had arranged emergency accommodation in Unite Church for people who were sleeping rough and did not have shelter, from 8pm on Thursday until Friday morning.
It would review the need for ongoing accommodation support on Friday, it said.
Nelson Tasman Civil Defence said rural support networks were contacting farmers earlier on Thursday to ensure their stock was safely out of flood zones.
It recommended that people stay away from rivers which could rise rapidly and to avoid travelling during heavy rainfall.
Far North District council monitoring situation
On Thursday evening, the Far North District Council said the weather situation would be monitored overnight, although rainfall in Northland had not been as heavy as initially expected.
There were some concerns for the very Far North and west coast areas with heavy rain expected after 9pm on Thursday, it said in a statement.
The Kāeo River and the Awanui River in Kaitāia were being closely monitored, although levels in both receded on Thursday, it said.