More than 70 domestic flights to and from Auckland Airport have been delayed or cancelled as fog creates chaos for hundreds of passengers.
Fog is finally starting to lift at the Mangere airport some four hours after it rolled in.
Forty-four flights between Auckland and Tauranga, Palmerston North, Napier, New Plymouth, Rotorua, Nelson, Whangarei, Gisborne, Taupo and the Bay of Islands have been cancelled.
A further 30 other flights between the city and Wellington, Christchurch, Dunedin, Queenstown, Kaitaia, Whakatane, Whanganui, Great Barrier Island and the Kapiti Coast have been delayed - in many cases by more than three hours.
Auckland Airport said fog restrictions were lifted just before 10.30am.
An Air NZ flight from Blenheim that was due in Auckland at 7.30am was diverted to Tauranga, and a Jetstar flight from Nelson due at 7.55am went to Palmerston North.
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The NZ Transport Agency warned the city's drivers to keep their headlights on and take care on the roads.
Airport operations supervisor Sam Cook said fog restrictions were put in place shortly after 6am.
"It escalated quite quickly this morning," he said.
International flights are operating as normal.
Passengers should check www.aucklandairport.co.nz or the airport's iPhone app for the latest flight arrival and departure information.
It's the third time in a week fog has gounded flights in and out of the Queen City.
Auckland Transport tweeted that ferry services were likely to be delayed.
A Herald reader who travelled into the CBD this morning from West Auckland said the city looked "ghostly", shrouded in a thick blanket of fog.
Police reported only one apparent fog-related crash on the roads, when a car hit two parked cars in Riversdale Rd, Avondale, about 7.30am. The driver was treated for minor injuries.