More than 30 domestic flights into and out of Auckland Airport were cancelled on Tuesday and a similar number delayed because of heavy fog.
Flights to and from smaller Whakatane, Tauranga and Nelson were cancelled, and some to New Plymouth and Palmerston North were also affected.
Most large aircraft were able to take off, but a JetStar flight to Christchurch, and one arriving from the city, were cancelled.
An airport spokesperson says about 32 flights were cancelled and a similar number delayed.
International flights were not affected.
The fog lifted late in the morning and airport staff worked to clear backlogs in the afternoon.