Southwest periodically make flights for further in the future available. The schedule was supposed to be extended on August 16th, but that was pushed back and the schedule was actually extended yesterday. You can now book flights until April 7, 2019. On September  27, 2018 the schedule will be extended again for flights until June 8, 2019. There was some hope that the schedule being extended was put off so that Hawaii flights would be bookable, but that’s obviously not the case.
Southwest has a pretty good cancellation/refunds policy, depending on the fare you’ve booked you’ll either receive a credit towards a future flight(Wanna Get Away) or cash refund (Business Select or Anytime – returned to credit card if you used one). That means it’s often best to book flights as soon as they become available and periodically check to see if the price has decreased, if it has you can click ‘change flight’.
