Between mid-June and mid-July flights from the country’s two biggest cities are seeing 60-80% of seats empty, data from the Civil Aviation Authority of Vietnam shows.
Last weekend, for instance, over 50% of seats on flights leaving the two cities were empty.
Airfares have been high and are likely to remain so through this summer due to a shortage of aircraft, analysts have said.
A Hanoi–Phu Quoc ticket on Vietjet now costs VND3.4 million, almost double the average rate in the first four months of this year.
The same flight costs VND2.7 million ($106) at Vietnam Airlines, same as the four-month average.
Airlines have been increasing night flights but they are not popular because of the inconvenience.
Vietnam Airlines canceled 10% of its night flights in May due to lack of demand.