The gusty winds were also expected to die down.
Earlier in the day
Wet weather has wrought 24 hours of chaos on Auckland roads and is set to unleash further misery on fans attending tonight's Fleetwood Mac concert.
The 38,000 concert-goers heading to Mt Smart Stadium should prepare for a wet night.
MetService was forecasting heavy rain to fall across the North Island today, and Auckland would not escape the stormy front.
Forecasters said Auckland was set to be drenched by heavy rain, which was unlikely to clear before midnight.
A revised forecast extended rain warnings from the central plateau through to Northland, including the Coromandel Peninsula.
MetService said the upper half of the North Island could expect periods of heavy rain. with up to 30mm of rain falling in three hours.
There was also the possibility of northwest gales over Northland, Auckland and the Coromandel Peninsula.
Promoters of tonight's Fleetwood Mac show said concertgoers should be prepared to be watch tonight's performance at Auckland's Mt Smart Stadium in rain.
Promoter Bridget de Launay said the show would go ahead rain or shine and unfortunately conditions were "pretty miserable".
"We're advising people to wear appropriate attire and allow a reasonable time to get there," said de Launay.
She also recommended people leave their umbrellas at home as they were not allowed in the stadium.
Meanwhile, the promoter of tonight's Elton John concert in Wellington said conditions were near-perfect and the 30,000 strong crowd could expect a stellar night.
As Auckland prepares for a further lashing from stormy spring weather, emergency services were kept busy attending more than 20 crashes overnight.
Police issued a warning to those behind the wheel to make allowances for slippery conditions.
"It's wet in the City of Sails and police are asking drivers to take care, drive to the conditions and reduce their following distances.
One of the more serious crashes involved a car smashing into a power pole on Orakei Rd in Remuera this morning.
Police northern communications Inspector Jason Greenhalgh said the female driver was not injured.
Last night police attended a score of minor car crashes around the region that were described as mostly "bumper to bumper type stuff".
In Northland, one person was briefly trapped in a car crash this morning.
Emergency services were called to Kaiwaka-Mangawhai Rd before 8am, after a van and a car collided near the intersection with Tara Rd.
A police spokesman said the van ended up on its side but there were no serious injuries.
