Counting Down The Days

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Southwest will officially begin flying from Boston Logan International Airport (BOS) in Massachusetts to San Diego International Airport (SAN) in southern California on a daily basis on Thursday, June 4. Flying westbound, these flights will have a maximum scheduled block time of six hours and 25 minutes this year, making them Southwest’s longest nonstop flights in the lower 48.

With the carrier planning to serve this route every day, a grand total of 211 rotations have been penciled in on this lengthy transcontinental corridor in 2026. Of these, 152 will be operated by the Boeing 737 MAX 8, alongside 51 with the 737-800 and eight with the 737-700. SAN noted last October that the eastbound leg back to Boston will operate overnight. In a statement, the airport explained how the new route will benefit passengers.

“Southwest is expanding its East Coast offerings, making it easier for San Diego residents and visitors to reach Boston, one of the nation’s key hubs for business, culture, and history.”

The Airline’s Other Longest Routes To, From & Within The Lower 48

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According to Cirium, an aviation analytics company, Southwest’s new route from Boston to San Diego is 10 minutes longer than its second-longest route across the lower 48 this year. The corridor in question links Baltimore Washington International Thurgood Marshall Airport (BWI) with San Francisco International Airport (SFO), and it will take a maximum of six hours and 15 minutes in 2026/

This puts it just ahead of the carrier’s longest international route, from Harry Reid International Airport (LAS) in Las Vegas, to Juan Santamaría International Airport (SJO) in San José, Costa Rica, which tops out at six hours and 10 minutes. Orlando to Sacramento ranks fourth, at six hours and five minutes, followed by Orlando to San Jose, California, at six hours exactly.

Dipping below six hours, passengers flying from Albany to Las Vegas with Southwest this year can reckon with a maximum westbound block time of five hours and 55 minutes. The remaining four routes in the top ten all originate in Baltimore, from which it takes up to five hours and 50 minutes to reach Sacramento and San Jose, and five minutes less to Los Angeles and Seattle.

Southwest Isn’t The Only Carrier Flying From Boston To San Diego

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Despite not holding the prestige of routes like John F. Kennedy International Airport (JFK) to LAX, the transcontinental corridor from Boston to San Diego is still an incredibly competitive battleground. Indeed, data from Cirium shows that four airlines have penciled in a grand total of 2,067 westbound departures on this route in 2026, with Southwest’s 211 flights only accounting for 10.2% of this total.

JetBlue has the greatest share, with 934 flights and 150,044 seats. All of these services use the Airbus A321. Alaska Airlines has 557 flights and 96,229 seats going from Boston to San Diego this year, primarily using the 737-900ER. Delta Air Lines accounts for the remaining 365 rotations, with all but one of these daily flights using the A321neo. The odd one out will see the 737-900ER instead.