Southwest’s Cheapest Winter Fares Stop Being Available Today

Southwest Airlines’ Week of WOW promotion ends today, September 17, and it is the kind of deadline that matters more than most airline sales because of what it covers. The discount runs up to 40 percent off base fares, and the eligible travel window stretches from October 5, 2026 through March 3, 2027 — which is to say it covers the entire winter, including the shoulder weeks on either side of the holidays when fares normally firm up rather than fall.

The conditions are straightforward but binding. Booking must be completed by today, and the fare requires a 21-day advance purchase, which means the earliest usable travel date sits comfortably inside the October window rather than in the next two weeks. Nonstop routes specifically named in the sale include Austin to San Diego, Nashville to Chicago Midway, Denver to San Diego, Seattle to Nashville, and Austin to San Jose, though the promotion is not limited to that list.

The surrounding offers run on their own clocks, which is where travelers tend to lose track. Rental car discounts through Enterprise give up to 15 percent off base rates on rentals of three days or longer, bookable through September 21 with vehicle pickup through December 15. Hotel bookings made between September 14 and September 21 earn either 3,000 Rapid Rewards bonus points or a 3,000-point discount, and those stays can be taken as far out as September 30, 2027. Vacation packages carry up to $500 off five-night trips for two, with free checked bags on eligible bookings.

The broader context is worth holding alongside the fare. Southwest has been reshaping its network through 2026, cutting 68 routes in the third quarter compared with the same period a year earlier and pulling back at several airports including Chicago O’Hare, St. Louis and Denver. A deep winter sale on the routes it is keeping is consistent with an airline concentrating capacity where it intends to compete and filling those seats early rather than discounting them in January.

Sources: Southwest Airlines Investor Relations, TravelPulse