Southwest Airlines Launches Its Longest International Route Ever

Southwest Airlines has announced the launch of its longest international route to date, connecting Las Vegas to San José, Costa Rica. This service will commence on October 1, 2026, marking a significant expansion for the carrier, which has only recently ventured into international markets. Currently, international flights account for merely 2% of Southwest’s total operations, a figure that reflects the airline’s extensive domestic focus since its inception over 54 years ago.

Previously, the longest commercial route operated by Southwest was from Los Angeles to Liberia, Costa Rica. That route, which spanned 2,283 nautical miles (approximately 4,428 km), was discontinued in 2017. Following this, the Denver to San José route briefly held the title until the airline’s new service surpasses it. The Las Vegas to San José route will cover 2,297 nautical miles (around 4,254 km) each way, and is expected to attract a substantial number of travelers.

The new route will feature daily flights on a 137-seat Boeing 737-700, making it the longest flight operated by this aircraft type from the United States. Booking data indicates a significant demand for this route, with over 38,000 round-trip passengers flying between Las Vegas and San José in the year leading up to November 2025. This makes it the second-largest unserved market to and from San José, trailing only behind Boston, which saw 62,000 round-trip passengers.

In addition to local demand, Southwest anticipates capturing a considerable number of connecting passengers from various cities across the Western United States. The top cities sending passengers to San José include Los Angeles, San Francisco, Seattle, and Phoenix, among others. Notably, only Los Angeles and San Francisco currently offer nonstop flights to the Costa Rican capital.

First Overnight International Service

With this route, Southwest will also initiate its first overnight international service. Previously, the airline had only offered red-eye flights on domestic routes. The Las Vegas to San José flight is scheduled to depart at 11:20 PM and arrive in Costa Rica at 6:00 AM the following day. This timing is a departure from the airline’s historical operations, which had seen flights from Houston Hobby to Cancun as its latest international departures this year.

Southwest plans to serve San José with six routes in total, including Baltimore, Denver, Houston Hobby, Las Vegas, Nashville, and Orlando. Once the Las Vegas flight arrives, the aircraft is expected to continue on to Florida, a common practice for the airline in managing aircraft flow across its network.

Replacing Denver-San José as Longest Route

The new Las Vegas to San José route will replace the existing Denver to San José route, which has been operational since March 2023. This shift is significant, as the new Las Vegas route will cover approximately 10% more distance compared to its predecessor. Unlike the Denver route, which operates primarily on a weekly basis, the Las Vegas service will run daily, enhancing Southwest’s ability to meet demand from the Western U.S.

According to data from the U.S. Department of Transportation for the period from December 2024 to November 2025, the Denver route carried only 12,114 passengers, reflecting its lower frequency. However, it did boast a strong load factor of 90.2%, indicating that demand remains robust. This data suggests that while the Denver to San José route may have been less frequent, it was still a viable option for travelers.

As Southwest prepares for this significant expansion, the airline appears poised to capture an increasing share of the international market, further establishing itself as a key player in the airline industry.