It’s generally more expensive to depart on a Friday, if you have to leave on this day you can still search on Cheapflights to find great options that meet your needs.
Due to multiple factors, expect to potentially pay more when booking in April. For low rates, February can be a great choice for travel to Bilbao. Flights to Bilbao from San Antonio in February are about $900 on average during February, but can be found for as low as $548.
It’s optimal to fly from San Antonio to Bilbao in the morning. By choosing this option you can save up to 10% on the cost of your flight, compared to a flight at noon.