UPDATED 9.55PM: Police say they're ready as New Zealanders prepare to welcome 2017 with a bang at the usual hotspots.

They have additional staff in areas such as Northland, Auckland, Mt Maunganui, Coromandel Peninsula, Queenstown and Wanaka.

In Auckland, about 30,000 people are expected in town for fireworks at Sky Tower.

Some 500 kilograms of fireworks and 10 kilometres of wire have been set for the midnight display, which will be live-streamed on SkyCity's Facebook page.

Three thousand shots will be fired in a show that will last just over five minutes.

There'll also be a free concert and DJ Max Key, the son of John Key, will be playing at the midnight moment.

Wellington City Council has organised a waterfront party from 8pm.

It's windy, but a council spokesman said fireworks displays at 9pm and at midnight are going ahead

There'll be fireworks too in Dunedin, where the council has organised a concert in the Octagon.

At midnight, the Robbie Burns Cannon will fire a single salute, and people are encouraged to sing along to Auld Lang Syne followed by the fireworks show.

In Central Otago about 7500 people are in Wanaka for the Rhythm and Alps music festival and in Gisborne behaviour at Rhythm and Vines was good in 2015 and organisers are looking for a repeat, having banned BYO alcohol.

Last year there were 22 arrests in the western Bay of Plenty on New Year's Eve but police say their presence is focused on prevention and helping those celebrating to stay safe.

Weather could put a dampener on festivities - There's a severe weather warning out for Wellington with heavy rain and gusts up to 120 kilometres an hour forecast for Wellington and the Wairarapa.

There's also a heavy rain warning for Westland, Buller, Wairarapa, Kapiti Horowhenua, Tararua and Wellington

Across the ditch, around 2000 police are patrolling Sydney as the city prepares for New Year celebrations.

More than a million excited spectators have already squeezed along the Sydney Harbour foreshore for the 9pm family fireworks and midnight main event.

It will pay tribute to music and film greats David Bowie, Prince and Gene Wilder, who all died this year.