All flights in and out of Wellington Airport have been suspended due to sea fog.

More than a dozen arrivals and departures were delayed this morning, including a 6.25am flight to Sydney which was delayed by more than two hours, according to the airport's website.

However, some flights were able to leave when the weather cleared momentarily.

Wellington police also issued a warning for motorists to take care in foggy and misty conditions.

Minor crashes had caused some traffic problems at Pukerua Bay, Porirua and Johnsonville.