Android users must also manually set the Pandora app to offline mode before leaving. That said, if you are a Pandora Plus or Pandora Premium subscriber, you will be able to play your downloaded music while traveling outside of the country temporarily, or going somewhere with via limited internet connection. Audio content streaming regulations differ from country to country, and we are still working on acquiring the proper licenses so we can offer Pandora in even more places around the world. Sadly, we can only legally offer Pandora services to listeners located in the United States at this time. This applies equally to free and paid accounts, as well as Pandora on all computers and supported devices, including offline. To upvote this idea, click on the icon next to the title of the request. If you'd like to see this suggestion implemented, please upvote this existing feature request: Offline Mode for Pandora Desktop App
Unfortunately, this isn't a feature of the Pandora desktop app.
Hey there, moved your post over to this existing thread to keep the community space organized: Listening Offline on Desktop App