Flights in and out of Wellington Airport have been delayed this morning as high winds are causing havoc for New Year's Eve travellers.

By 10.30am this morning, 17 arrivals and 15 departures had been either diverted or cancelled due to the blustery conditions, a Wellington Airport spokesperson said.

Some smaller aircraft had been able to land, but it was mostly the larger ATR aircraft and jets which were affected, he said.

The wind was forecast to ease this afternoon, he said.

Passengers have been advised to check their flight status with their airlines.

Wellington Airport customer and sales manager Scott Carr earlier said at least 20 Air New Zealand flights in and out of the capital had been cancelled.

Four flights were diverted including, three flights which were forced to return to Auckland and Christchurch and a flight from Nelson which was diverted to Palmerston North.

"Our teams are monitoring the conditions closely and working hard to get people where they need to be today," Carr said.

"Customers booked to travel are advised to keep an eye on our website for up-to-date travel information."

The MetService has issued a strong wind warnings for Wellington until 4pm on Sunday, forecasting gale north westerlies gusting 120km/h in exposed places.

Orange weather warnings are currently in place for the Marlborough Sounds, Wellington, Wairarapa extending south of Greytown and parts of Canterbury.

The unsettled conditions are set to put a dampener on New Year celebrations across some parts of the country.

Tauranga City Council said on Saturday it had made the decision to cancel its New Year's Eve community celebrations.

It said a heavy band of rain with possible thunderstorms and lightning is forecast to sweep through between 6pm to 9.30pm, when events were due to take place at five locations.

However, one group of Coromandel campers appear to be toughing it out for New Year's Eve despite heavy downpours.

Campers in Cooks Beach have shared video footage showing water pooling around tents and caravan awnings on Friday night.

Flaxmill Campground relief manager Chris Goldsbury said her campground was on higher ground, but it was still very wet underfoot this morning.

"We had a very heavy downpour probably about 7.30pm? And noticed we had 40mm measured in the rain gauge this morning ... but no, everybody was happy, we didn't have any problems."

Areas of the South Island are also in for a stormy start to 2024 with rain, hail and thunderstorms possible across areas of Canterbury, Otago and Southland.

The unsettled summer weather across the country has been largely influenced by the El Nino weather pattern, which has caused swings in temperature variations sparking thunderstorms and heavy downpours.