Bangkok Airways has cancelled all Samui flights on January 4 amid warnings of torrential downpours caused by the approaching Tropical Storm Pabuk.
Affected passengers can rebook flights without charges, the airline said.
Passengers can call the 1771 helpline or 02-270-6698 24 hours a day for reservation assistance and flight status updates.
Bangkok Airways said it would provide regular updates and apologised for any inconvenience.
Pabuk is expected to reach the shores of Thailand's South on Friday and Saturday.