Flights to and from Rotorua, Taupo and Whakatane were among those affected by fog this morning.
Around 30 flights were delayed and three were cancelled as fog caused disruption at Auckland Airport this morning.
Fog restrictions were put in place at 6.29am, the airport said, but were lifted after around an hour.
However, the restrictions caused a back-log at the departure lounge with around 30 domestic flights delayed.
Flights to Queenstown, Taupo, Kaitaia, Gisborne, Whakatane, Bay of Islands, New Plymouth, Palmerston North, Wanganui, Rotorua, Whangarei, Christchurch, Napier and Nelson were all delayed.