Travelers have found that booking a Wednesday departure is the best way to save up to 83% on the cost of booking your flights compared to booking on days of the week where this route is of high demand.
One of the essential ways to save on airfare from Portland to Koh Samui is to remain as flexible as possible. Flights that are at noon tend to be the most expensive. A flight in the morning could potentially save you up to 50% on airfare.