MetService says fog could cause more problems at Palmerston North Airport with "wok-like" conditions already cancelling eight flights.
An Air New Zealand spokesman said eight passenger flights in and out of Palmerston North had been cancelled this morning due to low cloud, with several other flights diverted to Whanganui.
Affected passengers were being accommodated by road or on later Air New Zealand services, he said.
MetService meteorologist Daniel Corbett said a patch of low cloud 300 metres above ground level had rolled in about 7.30am.
That was now breaking up, but light winds and a "rugged" looking high over the region meant it could return again tomorrow, he said.
"There's a lot of moisture at lower levels from the high, even though there has been no rain at all.
"It's like having a big wok and then you put the lid on it like this high has. Eventually the glass starts fogging up. It's the perfect recipe."
Conditions in Manawatu would remain relatively similar next day or two, but the fog was so patchy that there was only a small risk of more delays, Corbett said.
Those booked on flight to and from Palmerston North were advised to visit the Air New Zealand arrivals and departures page for the most up to date schedule and travel information.