Flights from St. Louis to Porto lean towards being more expensive in May. Prices are generally better when you fly from St. Louis to Porto in August, with the cheapest ticket starting at $538.
Unlike in the afternoon, when flights are generally more expensive, you can save up to 18% on flights from St. Louis to Porto by exploring options for tickets in the morning.
Users have found that leaving on a Sunday can be a cost-effective option. It’s possible to save up to 67% on your flight compared to booking on days when demand is much higher.