There have been three fatal crashes in Northland and the road toll has now risen to six in the North Island this weekend.
A man died after he tried to drive aross a flooded river in Omanaia, west of Kaikohe, just before 10pm.
He was trapped in the water and died at the scene, police said. A second person in the car escaped with minor injuries and raised the alarm.
Meanwhile, a passenger died when a car left the road and crashed into a tree on State Highway 1 at Towai, north of Whangarei just after midnight.
The driver was taken to Kawakawa Hospital in a serious condition.
Northland duty inspector Riki Whiu said both deaths had been referred to the coroner.
He said it was difficult for police to have two fatal crashes in the space of one night, and he reminded to people to drive to the conditions.
Also in Northland, one person has died after two cars collided head on State Highway 1 at Warkworth this afternoon.
The crash happened just after 3pm.
Police said another person had serious injuries and two others were moderately hurt.
State Highway 1 was closed between Woodcocks Road and Puhoi Road, but it has now reopened.
Police have asked motorists to avoid the area as traffic is heavy and weather conditions poor.
Three other deaths on North Island roads
In the latest of the other three incidents, one person died just south of Springs Hill, near Waiouru, when a single vehicle crashed at 5.45am this morning.
Yesterday afternoon a man died when he drove into a power pole in Hawera, in South Taranaki.
And in Auckland, a motorcyclist, who police say was speeding, failed to stop for officers at about 1.15am in Mt Albert.
He then missed a turn at the Royal Oak roundabout and fell off the motorbike, hitting a parked car.
He died at the scene.
The police were investigating and the Independent Police Conduct Authority had been informed, police said.