$94 Cheap United flights Boise (BOI) to San Diego (SAN)

You'll find affordable round-trip United Airlines flights from $157 from BOI to SAN by filtering your results from "Price (lowest to highest)" on Expedia. Or search for bargains from $94 for a one-way trip.**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.

Start searching one to three months before your departure to score cheaper fares on United Airlines flights from Boise Airport (BOI) to San Diego Intl. Airport (SAN). You can save 25% by booking your domestic flight 34 to 86 days in advance compared to last-minute reservations made 6 to 12 days out. You could also reduce costs by buying your fare on a Sunday, as it's 6% cheaper on average than a Monday, the most expensive day to book.* Get the timing right, and you can enjoy significant savings on domestic trips.*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.

Filter your results by "Early Morning" and "Morning" to find the earliest departures from BOI to SAN. Taking off early means you're 20% less likely to experience cancellations.**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.

Offering a rewarding loyalty program, United Airlines is a top pick for many passengers journeying from BOI to SAN. Plus, if you're a United Mileage Plus and One Key™ member booking through Expedia, you could earn OneKeyCash™* on eligible flights on top of your airline miles.*OneKeyCash™ disclaimer - OneKeyCash™ is not redeemable for cash and can only be used on Expedia, Hotels.com and Vrbo.