Cheap Southwest Airlines flights Tri-Cities (TRI) to San Diego (SAN)

Set the "Price (lowest to highest)" filter on Expedia to look for cheap Southwest Airlines round-trip flights from TRI to SAN. Affordable one-way tickets are available too.**These prices were available on Expedia within the past 7 days, for flights departing within the next year. Prices and availability are subject to change. Additional terms apply.

For cheap Southwest Airlines fares from Tri-Cities Regional Airport (TRI) to San Diego Intl. Airport (SAN), start searching one to three months before your intended departure. Reserving domestic flights 34 to 86 days in advance could save you 25% compared to booking just 6 to 12 days ahead. The day you book can also impact the cost. Sunday is typically the cheapest, while Monday is often the most expensive for domestic flights. You can save 6% on average by booking your trip on a Sunday.**Ideal booking window recommendation is based on average round-trip ticket prices for January through November for 2024. Best day of the week to book recommendation is based on average round-trip ticket prices for January through October 2024. All data sourced from ARC's global airline sales database.

Find Southwest Airlines's earliest flights from TRI to SAN by checking the "Early Morning" and "Morning" filters. Not only will you get to your destination sooner, early departures also have a 20% less chance of being canceled.**Most reliable time of the day recommendation is based on January through August 2024 flight status data sourced from OAG's global flight data platform.