Voters have one hour left to cast their ballot in the general election.
Nearly 3.1 million people, or more than 91 percent of those eligible, have registered to vote. Photo: RNZ
The Electoral Commission says polling booths throughout the country have reported steady flows of people since they opened at 9am this morning.
Despite severe weather in parts of the country, the commission said it has not had reports of any immediate impact on the turnout.
It said 717,579 people had cast advance votes - more than double the number of advance votes in 2011.
New Zealanders living abroad had until 5pm on Friday afternoon, their time, to get their votes in, and those will be counted as special votes, to be published on 4 October with the official election results.
There are more than 51,200 voters registered with an overseas postal address but that does not capture those who still have a New Zealand postal address.
The commission is aiming to have preliminary results from today's voting made public by 8:30pm tonight, with a full tally expected to be released by 11.30pm.
It said only a handful of complaints have been lodged, mostly about political signs still being up on election day.
Stormy weather as New Zealanders head to polls
The Electoral Commission said more people have registered to vote in today's election than at the last one in 2011.
A final total is yet to be released but the latest figures show 3,096,240 people have registered for the country's 51st general election, at least 20,000 more than three years ago.
At one central Auckland polling station this morning, there was a queue of about 40 people waiting to cast their vote when the polls opened at 9am.
Several party leaders voted in advance, including Labour's David Cunliffe, the Greens' Metiria Turei and Russel Norman, the Internet Party's Laila Harre, Maori Party co-leader Tariana Turia and the Conservatives' Colin Craig.
National's John Key, New Zealand First leader Winston Peters and ACT's Jamie Whyte voted in Auckland today.
Mana Movement leader Hone Harawira was expected to vote in Whangarei this afternoon while Maori Party co-leader Te Ururoa Flavell voted this morning in Rotorua.
United Future leader Peter Dunne also voted today, in Wellington.
Voters in many parts of the North Island were told to expect stormy, wet weather as they headed to the polls.
In the South Island, the weather was expected to be fine throughout much of the day but a southerly change was expected to bring showers to Southland, Otago and Canterbury later in the afternoon.
MetService issued a severe weather watch for Taranaki, Whanganui, Taihape, Hawke's Bay, Wellington, Northland, Auckland and Coromandel Peninsula.