Question : How often is the price changing when booking a trip from Porto Airport (OPO) to Dallas/Fort Worth International Airport (DFW)?
Answer : Prices for this trip tend to change a lot less than others. However, the sooner you book, the better price you tend to get.
Question : Can you cut down on flight costs by changing the day of the week you travel to Dallas?
Answer : Saturday is your cheapest day to fly in December. Having flexibility in your travel plans means you can save, so be sure to plan ahead when possible.