Christchurch Airport last month recorded the highest number of passengers through its terminal for any month on record.
Nearly 640,000 passengers used the terminal during December, up 4.8%.
Chief aeronautical and commercial officer Justin Watson said passenger numbers equated to more than the entire population of Canterbury and the West Coast.
International arrivals led the December growth, up 7.7% on December 2016.
The largest increases came on long-haul flights from Asia. China was up 41% on 2016, Hong Kong was up 79%, India 26% and South Korea 23%. European visitors also grew strongly at 12% out of the United Kingdom, the Netherlands, France and Germany, he said.
''It's not just passengers coming and going in record numbers. Our international carriers are also handling strong demand for South Island fruit, seafood and flowers exported directly to Asia.''
The growth highlighted the resurgent contribution Christchurch made as the primary gateway to the South Island, Mr Watson said.
It also reflected the significant airline capacity the airport had achieved with its new and existing airline partners in the past three years.
New services, or larger aircraft, were now flying between Christchurch and Guangzhou, Hong Kong, Perth, Melbourne, Sydney, Brisbane and the Pacific Islands, and domestically within New Zealand.
''Pleasingly, all our international partners are telling us most seats were full during December.''
The South Island tourism industry was the big winner from growth at Christchurch Airport, he said. Visitors arriving at Christchurch went on to visit more regions in the South Island than any other arrival point in New Zealand.
December was the start of the busy visitor season and strong growth was forecast to continue through until March.
