| Nonstop Flights: Austin to/from San Juan, Puerto Rico $267-$280 r/t [August-February] â Delta / American Airlines Delta and American Airlines have round-trip flights from Austin (AUS) to San Juan, Puerto Rico (SJU) for $267-$280, NONSTOP or with connections. Flights August to February. Weekends available. Origin/Destination reversible. Click for more details and booking links Nonstop Flights: Austin to/from San Juan, Puerto Rico $267-$280 r/t [August-February] â Delta / American Airlines . | 