| Nonstop Flights: Austin to/from Seattle $137 r/t [October-December] â Delta Delta has round-trip flights from Austin (AUS) to Seattle (SEA) for $137, NONSTOP. Flights October to December. Departures on Tuesday, Wednesday, and Saturday. Extended weekends available. Origin/Destination reversible. Click for more details and booking links Nonstop Flights: Austin to/from Seattle $137 r/t [October-December] â Delta . | 