Thick fog caused flights to be delayed at Rotorua, Whakatane and Hamilton airports earlier this morning.
An Air New Zealand spokeswoman said there were delays of up to an hour for flights in and out of the airports.
The delays could impact flight times at other airports, she said.
Despite heavy fog in parts of Auckland this morning, air travel was not affected at this point.
The New Zealand Transport Agency advised motorists to take extra care on the roads.
