Book by 11/12 11:59 p.m. Central Time.
Nonrefundable. 21-day advance purchase required. Seats, travel days, and markets limited. Blackout dates apply.
Fares valid on nonstop service where indicated; if not indicated, fares are valid on single connecting service.
Continental U.S. travel valid December 1, 2020 through March 4, 2021. San Juan, Puerto Rico travel valid January 11 through March 4, 2021.
International travel valid December 1 through December 9, 2020 & January 11 through March 4, 2021.
Check your destination here.
Example from St. Louis, MO.

Screenshot made on Southwest.com on 2020/11/10