Airport operations manager Richard Roberts said affected arrivals were a flight from Wellington due to land at 8.50am, another from Auckland due at 9.10am and a third from Christchurch due at 9.45am.
All three circled above the airport and landed between 10am and 10.30am, he said.
''I don't know how long they can circle in the air, but they would have known about the fog risk before taking off and likely allocated extra fuel for that. I have known of flights circling for about 40 minutes, because the disruption of returning to the origin or diverting elsewhere is huge,'' Mr Roberts said.
Normal airport operations resumed before 11am, a flight from Wellington landing as scheduled about 10.55am.
It was not unusual for the airport to be shrouded in fog in February, Mr Roberts said.
''Especially with the warm weather, there is more moisture in the air,'' he said.
A 6.50am flight bound for Wellington and another at 7.20am to Christchurch were able to get away on time.
At 8am, a flight from Christchurch landed in Dunedin, and 20 minutes later returned to Christchurch as scheduled.