Air New Zealand is warning many South Island flights this evening are likely to be disrupted by fog and low cloud.
The company said travellers booked to or from Christchurch, Dunedin, Queenstown and Invercargill should check arrival and departure information in case of changes.
It said customers who were booked this evening could transfer their bookings up until Sunday, or get a credit towards future travel.
And fog at Hamilton Airport has disrupted a flight forcing it to land in Auckland instead.
Trouble in Auckland
Earlier today, hundreds of passengers in Auckland faced delays and cancellations because of fog.
Auckland Airport said 60 domestic flights were cancelled and more than 40 were delayed.
One flight from Brisbane was also diverted to Wellington Airport.
Fog-related restrictions were imposed at 2.45am and were lifted and then imposed again several times during the day.
Some passengers waiting at the airport said they were tired of the delays and wanted to be on their way.
Kaya Levett was travelling to Nelson for her grandmother's 65th birthday this weekend and said her flight had been delayed up to five times this morning.
She had been at the airport for nearly five hours.
"I'm pretty fed up with the airport to be honest," she said. "I've been at the airport since 6:30 so I'm pretty over it, I'm ready to be on my flight and be out of Auckland now."
Ann-Marie was also trying to return to Nelson after a family holiday in Australia.
She said they were keen to get home.
"I'm a little bit frustrated but there's nothing much you can do about it," she said. "It's the weather so we're just going with it."