Southwest Flash Sale Offered Up to 40% Off Flights – Deal Expired
Southwest Airlines‘ September 2026 flash sale, which advertised up to 40% off eligible flights and a September 17 booking deadline, has expired. The promotion encouraged travelers to book selected flights during a limited reservation window, and the advertised discount was subject to the offer’s fare and travel restrictions.
The promotion’s headline discount did not mean every Southwest flight was available at 40% off. Eligibility depended on the specific itinerary and promotional conditions, and actual savings could differ between routes and departure dates.
Although the booking deadline has passed, the promotion provides a useful example of how Southwest’s limited-time airfare deals work, how percentage discounts are calculated, and what travelers should check before booking a future sale.
This article covers the September promotion, explains the difference between advertised and actual savings, and outlines practical ways to identify worthwhile Southwest flight deals.
Promotion status: Expired as of October 22, 2026. The September 17 booking deadline has passed, and the discount should not be presented as currently available.
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Southwest’s September 2026 Flash Sale at a Glance
Southwest launched the promotion on September 14, 2026, as part of its Week of WOW campaign. The airline’s official announcement confirmed the sale covered selected flights from October 2026 through early March 2027.
| Feature | September 2026 sale details |
| Airline | Southwest Airlines |
| Promotion | Week of WOW flash sale |
| Maximum advertised discount | Up to 40% |
| Discount applies to | Eligible base fares |
| Booking opened | September 14, 2026 |
| Booking deadline | September 17, 2026, at 11:59 p.m. PT |
| Eligible travel period | October 5, 2026–March 3, 2027 |
| Booking channels | Southwest.com and SWABIZ |
| Eligible ticket types | Qualifying one-way and round-trip reservations |
| Payment options | Cash or eligible Rapid Rewards points |
| Promotional code | Not required |
| Advance booking | At least 21 days |
| Blackout dates | Yes |
| Interisland Hawaii flights | Excluded |
| Current status | Expired |
The promotion applied to new qualifying reservations, with discounts displayed automatically during the booking process. Seats, travel days, and participating markets were limited.
How Did Southwest’s 40% Off Flight Sale Work?
The September flash sale reduced eligible Southwest base fares by up to 40% before government taxes and fees.
Passengers searching for qualifying flights during the promotional booking period could see the reduced fare automatically. There was no requirement to enter a discount code.
However, the discount was not available on every flight or every travel date.
Did Southwest Offer 40% Off the Entire Ticket Price?
No. The discount applied to the eligible base fare, not necessarily the final ticket price.
Government taxes and mandatory fees were calculated separately.
For example, consider a hypothetical flight with a $200 base fare and $30 in taxes and fees.
| Fare component | Regular price | With a 40% base-fare discount |
| Base airfare | $200 | $120 |
| Taxes and fees | $30 | $30 |
| Total ticket price | $230 | $150 |
| Total savings | — | $80 |
Although the base fare decreased by 40%, the total ticket price decreased by approximately 34.8%.
This example is illustrative rather than an actual Southwest fare from the promotion.
The difference matters because travelers comparing airline deals should evaluate the complete ticket cost, including any additional services required.
Which Southwest Routes Were Included in the September Sale?
Southwest’s September 2026 promotion covered selected domestic and international routes, including qualifying flights within the continental United States and services to certain leisure destinations.
The airline highlighted several nonstop city pairs in its official Week of WOW announcement.
Examples of Routes Featured in the Sale
| Departure city | Destination | Airport codes |
| Austin | San Diego | AUS–SAN |
| Nashville | Chicago Midway | BNA–MDW |
| Denver | San Diego | DEN–SAN |
| Seattle | Nashville | SEA–BNA |
| Austin | San Jose | AUS–SJC |
These were examples of participating routes rather than an exhaustive list. A route’s inclusion did not guarantee that every departure had a discounted seat.
The promotion also covered selected travel involving Hawaii, Puerto Rico, the U.S. Virgin Islands, and international destinations, subject to additional restrictions.
Were Hawaii Flights Included?
Yes, qualifying flights between the continental United States and Hawaii could be included.
However, flights operating entirely between Hawaiian islands were excluded.
Travel to and from Hawaii also followed different eligible travel days and blackout periods from those applying to ordinary continental U.S. itineraries.
What Were the Travel Date Restrictions?
The September sale covered qualifying flights departing between October 5, 2026, and March 3, 2027.
However, several high-demand periods were excluded.
Southwest September Flash Sale Blackout Dates
| Route category | Excluded travel dates |
| Within the continental U.S. | October 12, 2026 |
| Within the continental U.S. | November 20–25 and November 28–30, 2026 |
| Within the continental U.S. | December 18, 2026–January 4, 2027 |
| Within the continental U.S. | February 12 and February 15, 2027 |
| Continental U.S. to international destinations, Hawaii, St. Thomas, and Puerto Rico | November 19–25, 2026; December 17, 2026–January 5, 2027 |
| Return travel from those destinations to the continental U.S. | November 27–December 1, 2026; December 17, 2026–January 5, 2027 |
These restrictions appeared in the September promotion’s published terms.
The exclusions were particularly relevant around Thanksgiving, Christmas, New Year, and other high-demand travel periods.
Which Days of the Week Qualified?
The promotion also restricted eligible departures according to the route category.
| Travel category | Eligible days |
| Within the continental U.S. | Monday–Saturday |
| Continental U.S. to Hawaii, St. Thomas, and international destinations | Sunday–Wednesday |
| Hawaii, St. Thomas, and international destinations to the continental U.S. | Tuesday–Friday |
| To or from Puerto Rico | Monday–Thursday |
Travelers with flexible departure dates had more opportunities to find qualifying fares than those restricted to specific weekends.
Could Rapid Rewards Members Book Discounted Flights With Points?
Yes. Southwest’s September 2026 sale also applied to eligible flight reservations booked using Rapid Rewards points.
Because Rapid Rewards award pricing is closely linked to cash fares, lower eligible base fares could translate into lower point requirements.
For example, the reference coverage identified a Las Vegas–San Francisco award itinerary priced at approximately 5,500 Rapid Rewards points during the promotion. That was a historical example, not a guaranteed fare available today.
Did the Sale Make Rapid Rewards Points More Valuable?
Not necessarily.
A discounted award flight could require fewer points, but the value received per point would generally remain related to the underlying cash fare.
Travelers comparing payment methods should consider both the points required and the taxes and fees payable.
Award tickets also remain subject to applicable government charges, including a minimum U.S. security fee of $5.60 per one-way itinerary where applicable.
Did the Discount Apply to Existing Southwest Reservations?
No. The September promotion was intended for new qualifying reservations made during the booking period.
An existing ticket did not automatically receive the promotional discount.
Travelers who had already booked a flight could compare the current fare with the original ticket price. If a lower eligible fare was available, canceling and rebooking might have been an option under the ticket’s applicable rules.
However, canceling an existing reservation could affect refunds, flight credits, seating, and availability.
The September promotion also specified that subsequent itinerary changes could cause the promotional savings to be forfeited.
What Should Travelers Know About Southwest’s Fare Types?
Southwest’s lowest advertised fares do not necessarily include the same flexibility and services as its higher-priced tickets.
The airline introduced a revised fare structure with Basic, Choice, Choice Preferred, and Choice Extra options.
Southwest Fare Categories
| Fare type | General characteristics |
| Basic | Lowest-priced option with more restrictive conditions |
| Choice | Standard fare with additional flexibility |
| Choice Preferred | Additional seating and travel benefits |
| Choice Extra | Higher-tier fare with more included benefits |
The cheapest promotional fare may not always represent the lowest overall travel cost.
For example, a passenger requiring checked baggage or a particular seat should compare the total price of a Basic ticket with the cost of a higher fare that includes the required benefits.
Were Checked Bags Free During the Sale?
Not automatically.
Southwest ended its universal two-free-checked-bags benefit for most new reservations beginning May 28, 2025.
Checked baggage allowances now depend on the purchased fare, Rapid Rewards status, eligible credit card benefits, and other applicable exceptions.
A discounted Basic fare therefore does not necessarily include complimentary checked baggage.
How Could Travelers Find the Lowest Southwest Sale Fares?
During the September promotion, eligible discounts were automatically displayed through Southwest’s booking channels.
The process involved selecting a qualifying route, searching within the permitted travel period, and comparing available fares.
Using Southwest’s Low Fare Calendar
Southwest’s Low Fare Calendar allows travelers to compare prices across multiple dates.
For example, a traveler planning a trip between Denver and San Diego could compare several departure dates rather than selecting a single weekend.
This is particularly useful during promotions that exclude certain weekdays or high-demand periods.
A lower fare on a nearby departure date may provide greater savings than the headline discount on a less convenient itinerary.
Why Comparing the Final Fare Matters
An advertised 40% reduction does not guarantee the lowest available ticket price.
Airfare can change according to demand, available inventory, and booking conditions.
Travelers should compare:
- The final round-trip or one-way price.
- The fare type and included services.
- Checked baggage and seat selection costs.
- Departure and arrival times.
- Connecting versus nonstop itineraries.
- Cancellation and flight credit conditions.
A promotional fare should be assessed against other available options rather than relying exclusively on the advertised discount percentage.
Is Southwest Offering Another 40% Off Sale in October 2026?
Yes. A separate Southwest promotion is available through October 22, 2026, according to current published coverage. This is a new offer, not an extension of the September sale.
The October promotion advertises up to 40% off qualifying base fares for selected flights booked between October 19 and October 22, 2026, with eligible travel generally from November 9, 2026, through March 3, 2027.
| Feature | September promotion | October promotion |
| Maximum discount | Up to 40% | Up to 40% |
| Booking deadline | September 17, 2026 | October 22, 2026 |
| Travel begins | October 5, 2026 | November 9, 2026 |
| Travel ends | March 3, 2027 | March 3, 2027 |
| Promo code | Not required | Not required |
| Status on October 22 | Expired | Scheduled to end October 22 |
| Blackout dates | September offer rules | Different October offer rules |
The October offer is reported to end at 11:59 p.m. Pacific Time on October 22. It has different blackout dates and eligible travel conditions.
Travelers interested in the newer promotion can check Southwest’s official website for currently available fares and applicable terms.
How to Find Future Southwest Flight Sales
Southwest periodically offers discounted fares, promotional Rapid Rewards opportunities, and seasonal travel deals.
Several practices can make these promotions easier to evaluate.
Monitor Official Southwest Offers
The airline’s official website publishes available promotions and booking conditions.
Promotional emails and Rapid Rewards communications may also announce limited-time discounts.
Compare Multiple Travel Dates
Flexible departure dates can make a substantial difference in airfare.
Travelers who can depart on a Tuesday or Wednesday instead of a high-demand Friday may find more affordable options, depending on the route.
Check Cash and Points Prices
Rapid Rewards members can compare cash fares with award pricing before booking.
A discounted cash fare may be attractive for travelers saving points for future trips, while a reduced award price may help members use an existing balance.
Review Fare Restrictions
Before completing a booking, travelers should check the cancellation rules, baggage allowance, seating conditions, and any restrictions on promotional fares.
The lowest advertised ticket price may not be the most suitable choice for every itinerary.
Related: Best Southwest Airlines Credit Cards of October 2026
Final Thoughts
Southwest’s September 2026 Week of WOW sale provided an opportunity to save up to 40% on selected base fares for travel between October 5, 2026, and March 3, 2027. However, the booking deadline passed on September 17, making the original promotion unavailable.
The sale demonstrated the importance of checking blackout dates, eligible travel days, advance-purchase requirements, and the total ticket price before booking.
Travelers looking for similar savings can review Southwest’s newer October 2026 promotion, which has a separate booking deadline and different restrictions. For any future sale, comparing fares across several dates and checking the included baggage and seating benefits remains essential.
Frequently Asked Questions!
The September 2026 flash sale ended on September 17, 2026, at 11:59 p.m. Pacific Time.
Week of WOW was a September 2026 promotional campaign offering discounts on eligible Southwest flights and selected travel-related products, including hotels, car rentals, and vacation packages.
No. The discount was applied automatically to qualifying bookings made during the promotional period.
Yes. The offer covered qualifying one-way and round-trip reservations, subject to the applicable route and travel restrictions.
Yes. Selected international routes were eligible, although blackout dates and permitted departure days differed from domestic travel.
Some dates were eligible, but several peak holiday travel periods were excluded. Thanksgiving, Christmas, and New Year restrictions significantly limited the available dates.
No. The published September offer stated that the discount could not be combined with other promotional fares or discounts.
No. The promotion advertised savings of up to 40% on selected base fares. Actual discounts depended on the route, flight, date, and available inventory.
Yes. Eligible Southwest fare sales may also reduce the points required for qualifying award flights. Taxes, fees, and applicable booking conditions still apply.