Southwest Airlines offers up to 40% off base fares in flash sale

Southwest Airlines is conducting a flash sale offering up to 40% off base fares for both paid and award flights. The promotion is valid for qualifying one-way or round-trip fares booked by September 17, 2026, at 11:59 p.m. PT.

Travel under this sale is valid between October 5, 2026, and March 3, 2027. Specific blackout dates apply for continental U.S. travel, including several dates in October, November, December, and February. Additionally, travel to or from international destinations, Hawaii, St. Thomas, and Puerto Rico is subject to specific blackout periods during late November and the December holiday season.