| Nonstop Flights: Austin to San Diego $157 r/t [September-November] (Tue/Wed/Sat) â Southwest Southwest has round-trip flights from Austin (AUS) to San Diego (SAN) for $157 with a connection. $59 each-way. Tuesdays, Wednesdays, or Saturdays. Flights September and November. Origin/Destination reversible. Southwest doesnât charge a fee for changes, cancellations, or carry-on bags. Click for more details and booking links Nonstop Flights: Austin to San Diego $157 r/t [September-November] (Tue/Wed/Sat) â Southwest . | 