Flights The sale ends Sept. 17. A Southwest Airlines plane pulled into a gate at Pittsburgh International Airport on March 27. Gene J. Puskar

Travelers can save money on trips booked this week on Southwest.

The airline launched a four-day “wow” sale on Monday, offering 40% off base fares for travel between Oct. 5 and March 3, 2027. The offer ends Sept. 17 at 11:59 p.m. PT.

The sale applies to continental U.S. travel Monday through Saturday, Puerto Rico travel Monday through Thursday, and Hawaii, St. Thomas, and international travel Sunday through Wednesday.

Travelers should note the following blackout dates for continental U.S. travel: Oct. 12, Nov. 20-25, Nov. 28-30, Dec. 18-Jan. 4, Feb. 12, and Feb. 15. International travel and travel to Hawaii, St. Thomas, and Puerto Rico is blacked out Nov. 19-25 and Dec. 17-Jan. 5, 2027.

The discount is applied before government taxes and fees, and additional fees may apply. The deal is for new reservations only, and seats, travel days, and markets are limited.

Those interested in the deal can book on Southwest.com.

Southwest ranked among the best airlines for customer satisfaction in the JD Power 2026 North America Airline Customer Satisfaction Study, ranking No. 1 for economy/basic economy for the fifth consecutive year.