New Year's Eve 2017: How we led the world's celebrations

AS the rest of Australia rolled out its New Year's Eve celebrations, thousands were evacuated from a beach on the NSW Central Coast after a fireworks barge caught on fire during NYE celebrations.

The barge caught fire during the 9pm fireworks at Terrigal.

Two pyrotechnicians were forced to jump off a fireworks barge on the NSW Central Coast and suffered minor injuries after a NYE display went horribly wrong.

Crowds were evacuated from the Terrigal beach after the barge caught fire just minutes into the New Year's Eve fireworks show shortly after 9pm. NSW Fire and Rescue said the two technicians were helped by onlookers before being treated by paramedics.

It came as more than one million people descended on Sydney Harbour to watch the city's famous fireworks. A billion people were said to be watching on television.

The clocked ticked over to 2018 and Sydney did what it does best with a dazzling pyrotechnics display that drew cheers and gasps from the huge crowd who packed vantage points around the harbour.

Some eight tonnes of fireworks produced 100,000 individual pyrotechnic effects as the sky exploded in a riot of colour and light, with the centrepiece a rainbow tribute to the nation's historic same sex marriage vote and the upcoming 40th anniversary of Mardi Gras.

Among the crowds were same-sex couples, still basking in the recent victory of the yes vote.

Alex Parkes, who watched the fireworks with his partner, said the tribute had made him feel part of a greater community.

"I think it's a beautiful reminder of the progress achieved this year and exactly how far we've come," he told AAP.

For the first time, there was a countdown to midnight, with fireworks forming the numerals 10 to one on the Harbour Bridge.

The word "Sydney" then spread across the arch before a multicoloured waterfall of fireworks cascaded down from the world famous structure.

All harbour vantage points were full two hours before the 9pm family fireworks lit up the harbour, building excitement for the main event which cost $7 million and lasted 12 minutes.

The show also included a section of fireworks designed by actor Hugh Jackman.

Almost 45 per cent of those watching around the harbour were international tourists. Guides are written in Chinese, Korean, Japanese, Spanish and German.

British holiday-maker, William Capstick, made sure his timing in Australia lined up with New Year's Eve so he could see the fireworks.

"It was amazing to see the harbour that way - the bridge and Opera House are so well known so it's so insane to see it like that," he told AAP.

He said the size of the crowd was something he didn't foresee but said it was handled much better than his own capital city's New Year's Eve celebrations. "The city, right now, is packed as - but the police are moving everyone through quite well," he said.

"Better than London - by far." Dozens of roads were shut down entirely in the CBD and the swelling crowds wandered down the empty streets past heavily armed police, anti-riot squads and into corrals around Circular Quay.

By 11.30pm police stopped the crowds entering entirely - forcing thousands to scramble for a view of the bridge between the skyscrapers.

"It's bloody chockas," one officer told AAP. "You wouldn't even get close."

In Melbourne, thousands were undeterred by security fears despite the celebrations coming 10 days after a fatal vehicle attack near Flinders Street Station as revellers partied in 2018 underneath a spectacular 14-tonne fireworks show across the city.

Thunderstorms had threatened to dampen New Year's Eve celebrations in Brisbane but the city dodged the worst of the severe weather that hit other areas, and revellers on the city's foreshores enjoyed two stunning pyrotechnic displays at 8.30pm and midnight.

Revellers in Ipswich weren't so lucky, with the council posting on social media that organisers had been forced to cancel its New Year's Eve celebrations because of the weather.

In Adelaide, revellers in Glenelg and the CBD were treated to fireworks displays at 9pm and midnight.

Earlier, hundreds of thousands of New Zealanders have taken to streets and beaches to become among the first in the world to usher in 2018.

As the new year dawned in New Zealand, fireworks boomed and crackled above city centres and harbours, and partygoers sang, hugged, danced and kissed.

In Auckland, tens of thousands gathered around the Sky Tower as five minutes of non-stop pyrotechnics exploded from the tall structure's upper decks.

Earlier, Lord Mayor Clover Moore said that the City of Sydney had worked closely with NSW Police to make sure the $7 million show is a success.

"There are extra (security) measures tonight, but there's no particular concern, they're just measures that are being taken because of the sorts of things (terrorism) that have been happening around the world," Ms Moore told reporters.

"We have always had a really fabulous, very safe event, and that's what we're counting on doing again tonight." NSW Police will use vehicles to block off roads "where appropriate" in an attempt to ensure no-one can use a truck to attack partygoers. There'll also be concrete and water-filled bollards strategically located across the city.

A high-visibility police operation swept Circular Quay on Sunday morning with officers using mirrors to look for threats.