A state of emergency remained in place on Saturday in the city of 1.6 million people on New Zealand's north island as the rains eased after Friday's flooding in the north, northwest and west.
Prime Minister Chris Hipkins, less than a week in office, flew by helicopter over the city before touring flood-hit homes.
"The level of devastation in some areas is considerable," Hipkins told reporters, describing the event as "unprecedented" in recent memory.
Daylight revealed the impact of the storm, caused by warm air descending from the tropics, sparking heavy rain and thunderstorms, said Auckland Emergency Management, part of the city's council.
"Auckland was clobbered on Friday – Auckland's wettest day on record – and today we start the clean-up," the agency's duty controller, Andrew Clark, said in a statement, urging caution for residents returning home to survey flood damage.
While heavy rain had eased, another period of downpours was possible on Sunday, the national weather forecaster said.
Showers were "dotted around Auckland" with some heavy west of the city, Auckland Emergency Management tweeted, while warning residents to "stay safe" amid the emergency.
"We're not out of this yet. Heavy rain returns tomorrow," the agency wrote on the social media platform.
Two men were found dead, New Zealand Police said. A search was under way for a man believed swept away, while another person was unaccounted for after a landslide hit a house in an inner Auckland suburb, police said.
More than 2,000 calls for assistance and 70 evacuations had been made around the city, the New Zealand Herald reported.
City rainfall records were broken, with Auckland Airport logging 249 millimetres in the 24 hours to 9am on Saturday, beating the 1985 high of 161.8mm.
Some local flights resumed at Auckland Airport, which had closed domestic and international operations on Friday.
Air New Zealand said its domestic flights in and out of Auckland resumed from noon, and advised it was assessing whether international flights would also restart.
The airport, on its website, said it was scheduled to open its international terminal for departures from 5pm, while international arrivals would restart at 4.30am on Sunday.
Air New Zealand said 12 of its international flights due into Auckland had been diverted overnight.
On Friday, social media showed firefighters, police and defence force staff rescuing stranded people from flooded homes using ropes and rescue boats.
The flooding forced cancellations of British pop star Elton John's concerts in the city, which had been scheduled for Friday and Saturday nights.
