Fog has caused flight cancellations and delays at Dunedin airport.
The first Air New Zealand flights from Wellington and Christchurch on Friday were not able to land and there were no planes for the return services.
Air New Zealand says the Christchurch flight had to turn back and the Wellington service was diverted to Invercargill.
In all, at least five Air New Zealand flights were cancelled or redirected to other airports.
Airport chief executive John McCall says the morning's fog was the thickest for many months, but airlines were catching up the backlog during the day.
