Southwest is nearly 55 years old. It has grown to become the US’s third-largest airline by seats for sale, behind American and Delta. Its sheer scale means it does not grow quickly at the best of times. Indeed, in March 2026, Cirium Diio data shows that its capacity has fallen marginally compared to the same month last year.

Still, it does, of course, add new routes—and sometimes many of them. Exploring its entire schedule shows that 31 additional routes will take off between March 2 and 8. Unusually, that’s more than half the number of new links compared to what Allegiant, Breeze, Delta, and Frontier will begin in the same period.

Southwest Begins These 31 Routes Next Week

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The map above illustrates them all. It is derived from comparing the carrier’s entire network between January 1, 2025, to March 1, 2026, with what will begin at some point between March 2 and 8, 2026. The sheer number of airport pairs means that I have not provided a full table of details, although I usually always do.

Some 25 of the routes are domestic, while six are international. The latter comprises Indianapolis to Los Cabos; Kansas City to Punta Cana; Nashville to Montego Bay and San José; St. Louis to Puerto Vallarta; and San Diego to Puerto Vallarta. Five of those six markets are brand-new to Southwest’s map. The sole exception is San Diego to Puerto Vallarta, which was served between March 2018 and April 2020. It is the first time that Southwest has flown internationally from Indianapolis and Kansas City.

Nashville and San Diego have gained five routes each. The Tennessee airport, which will be Southwest’s seventh most-served facility in March, now has flights to Knoxville, Little Rock, Montego Bay, Montrose, and San José (Costa Rica), all of which have not previously been served. Connections will be critical, especially for the very short intrastate hop from Knoxville. Then there’s San Diego, with Bozeman, Kahului, Puerto Vallarta, Seattle, and Spokane. While all have been served before, it is taking the fight to Alaska Airlines.

Four Of The Additions Are Particularly Short

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The average stage length of all 31 routes is 848 nautical miles (1,571 km), which is influenced by the long legs from Kansas City to Punta Cana and San Diego to Kahului. But look closely, as there are several very short additions, which include Chicago Midway to Milwaukee, Dallas Love to Oklahoma City, Nashville to Knoxville, and Phoenix and Tucson. Of these, only Dallas Love to Oklahoma City has seen Southwest before (for decades until 2020).

As all those routes are very short, they have next to no local traffic. As such, they’ll be served for countrywide connectivity reasons. After all, Phoenix is the carrier’s third-busiest airport, Midway is fifth, Love is sixth, and Nashville is seventh. The airline is growing its hub-and-spoke-type markets to funnel an increasing number of passengers, and these are the latest part of it.

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Introducing Southwest’s New 2nd-Shortest Route

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At just 70 nautical miles (130 km) each way, Midway to Milwaukee perhaps stands out the most. It is Southwest’s new second-shortest market, after Denver to Colorado Springs, which has been part of its network since 2021.

Its first departure from Illinois to Wisconsin will take place on March 5, with a double daily operation. The 137-seat Boeing 737-700 will primarily be used. The first week’s schedule, as changeable as it is, is shown below.