South Korea’s main international gateway, Incheon Airport, has the worst on-time performance among major airports, a report showed.

According to the report by Flightstats, a global flight information service provider, the airport located west of Seoul ranked 44th in terms of departure performance at major hubs last month, with an average 50.04 percent on-time record.

On-time departures are calculated by checking if a plane has taken off within 15 minutes of its scheduled departure time, the report said.

As the reasons behind Incheon Airport’s low ranking, experts cited increased flight traffic due to newly added flights from China, Europe and the Middle East, in addition to bad weather in winter.