Police say they have had to rescue a number of people trapped in cars and homes threatened by floodwaters in Northland.
The equivalent of two months of rain has fallen over the past 24 hours, with even more rain and flooding, expected overnight Monday.
Inspector Ian Booker says police have had to rescue people in almost every town in Northland.
He says late Monday afternoon police rescued a number of people from the tops of their vehicles who became trapped on a bridge near Hikurangi.
Earlier Monday fire crews used inflatable boats to evacuate a family from their home in Scows Landing.
In Otaika a woman was rescued by neighbours after being swept into floodwaters.
High tide was expected to hit at around 6pm, bringing flooding to areas south of Kaikohe.
Civil Defence said Whangarei's city centre could also flood if the rain is intense.
A number of roads are expected to remain closed overnight, because of slips and surface flooding.
Motorists are being asked to stay off the roads across the region.
Heavy rain and strong winds battered the top of the North Island on Monday, causing flooding, landslips and road closures.
Several roads in Northland are closed due to surface flooding and slips, including parts of the main state highway to Cape Reinga. State Highway 1 north of Te Kao at Kaeo and at Moerewa is closed.
Police say some communities in Northland have been cut off. Inspector Willie Taylor says officers have received a high number of calls in relation to surface flooding and trees falling on roads.
Roads into Kao, Ngunguru and Whangerei Heads are either closed or accessible by four-wheel-drive vehicles only.
Meanwhile, the Fire Service says it had to use a rubber boat to help evacuate a family whose house has been flooded in Ngunguru.
Crews are also helping a group of people in a car stuck in flood waters in Portland near Whangerei.
Northland's Civil Defence says there were power cuts in some areas on Monday morning.
More bad weather forecast further south
MetService says heavy rain is also expected in the Bay of Plenty and northwards to Auckland and in Wairarapa.
Galeforce wind warnings have been issued for Taranaki and Taupo.
People are advised to watch for rapidly rising streams and rivers, slips, flooding and hazardous driving conditions.
