| Cheap Flights: Austin to/from San Francisco $130-$139 r/t [Jan-May.2021] â Southwest Southwest has round-trip flights from Austin (AUS) to San Diego (SAN) for $130-$139, NONSTOP or with a connection. $65 each-way. January to May 2021. Origin/Destination reversible. Southwest does not charge any change or cancellation fees. Want a notification sent straight to your phone when any new deals are found? Join our Telegram channel and never miss another deal. We donât charge a subscription fee. All of our deal notifications are available for FREE via Instagram, Facebook, Twitter, Telegram, our Webpage, and our E-mail list. If you are paying someone a subscription fee for our content, you are being ripped off. We send out a daily recap of every fare that is priced less than the 9-month moving average to our Patreon Supporters. If youâre interested in our analytical content, consider supporting our work on Patreon. Click for more details and booking links Cheap Flights: Austin to/from San Francisco $130-$139 r/t [Jan-May.2021] â Southwest . | 