A number of North Island roads are closed as a result of bad weather with MetService forecasting heavy rain for the top and east coast of the island.
A tree fell on a car in Waimauku, north-west of Auckland, but no-one was hurt.
A number of roads are closed in Waikato,Taranaki and near Palmerston North.
Trees and power lines are blocking both lanes of State Highway 39 at Ngāhinapōuri in Waikato.
In Taranaki, State Highway 45 between Pungarehu and Warea is closed at the intersection with Newall Road because of flooding.
The Saddle Road between Ashhurst and Woodville is closed near Palmerston North, and there are speed restrictions further north on State Highway 54 at Ohingaiti because of slips.
Firefighters have dealt with 29 call-outs for problems like fallen trees and flooding caused by heavy rain in Waikato, Auckland, Northland and the Bay of Plenty.
Some Auckland residents have been without power since 10.30pm last night, with the power company Vector's power cut map showing a swathe of unplanned blackouts in the city this morning.
A spokesperson said residents in Karekare, Huia, Torbay Heights and Parau were the worst affected and contractors were working to resolve the issues as quickly as possible.
The MetService has a number of orange heavy rain warnings in place for the upper North Island and the east coast of the North Island which it says could cause surface flooding and make driving conditions hazardous.
Heavy rain warnings are in place until 7pm today for Waikato with up to 130mm of rain expected to fall, Gisborne where up to 280mm is expected and Bay of Plenty east of and including Whakatāne where up to 160mm is forecast.
A heavy rain warning is in place for Hawke's Bay north of Napier until 4pm with up to 130mm of rain expected about the ranges and up to 110mm near the coast.
Waka Kotahi was warning North Island motorists to take extra care as thousands of holidaymakers return home from a long weekend away.
Waka Kotahi spokesperson Andy Knackstedt said motorists should drive to the conditions and be patient in the potentially hazardous conditions.
People could keep up to date with closures by checking the transport agency's website, he said.
Taranaki clean-up
A rural Taranaki school might not be opening tomorrow after it was hit by flooding.
Yesterday New Plymouth had the equivalent of a typical July's-worth of rainfall in just four hours.
Flooding swept through Rahotu, a rural town about 40 minutes south of the city. A tweet from MetService yesterday showed flood waters raging through the school, although the red level rain warning for Taranaki has now been lifted.
Rahotu School principal Brigitte Luke said they will try to assess the damage today once the water's receded and if roads can be crossed to get there.
She said one of the priorities will be ensuring the sewerage system's held up.
She said students and staff are equipped for at-home learning if that is what is required until the school can open.
MetService says New Plymouth usually averages 82mm of rain across the entire month of February.
But it said between Saturday and Sunday New Plymouth received 192.6mm of rain, while Mt Taranaki received 485mm.