They were lifted at airports in Hamilton, Rotorua and Taupo at approximately 2pm.
"As you can imagine, our operations teams are working to get customers to their destinations and are not placed to provide me with specific numbers,'' she said.
Auckland Airport's Operations Centre said a total of 18 domestic regional flights had been cancelled due to the fog and 12 domestic regional flights had been delayed because of it.
One flight from Wellington, one from Christchurch, one from Dunedin and one from Queenstown had all been delayed into Auckland because of this morning's conditions.
No main trunk domestic or international flights had been affected.
It is not yet known how many people have been caught up in the delays and cancellations and whether any passengers had been travelling to Wellington for tomorrow night's big All Blacks and Lions test match.
WeatherWatch said this afternoon foggy conditions were not expected to be repeated any time soon.
"Fog is not expected tonight - at least not widespread of around our airports.
"As winds continue to build over the next 24 hours, becoming blustery on Saturday in exposed parts of the North Island, fog will be even less likely.''
Meanwhile, Wellington Airport is preparing for what they say will be one of their busiest weekends ever, thanks to those coming arriving to see the All Blacks versus Lions showdown tomorrow.
Spokeswoman Arpita Dutta said they were expecting 22,000 passengers through Wellington Airport and 23,000 to come through on Sunday.
"There are seven Air New Zealand chartered flights arriving with fans for the second test match including two wide-body Boeing 777s.
"Wellington Airport has been preparing for the major event over the last few months; working closely with the entire airport community to ensure the travel process is as smooth as possible.''
Up to 22 buses will bring passengers to the airport from the stadium following the game to catch the eight chartered departing flights scheduled tomorrow night.
Five other chartered flights will leave Wellington on Sunday, while Qantas is also running three of those domestic chartered flights.
"If you're travelling out of Wellington this weekend, it will be a little busier than normal at the airport so try and arrive a little earlier than normal, check-in online if possible and pre-book parking online.
"You should also check the website for flight times and check NZTA website for any traffic updates."