$285 Cheap American Airlines flights St. Louis (STL) to Hermosillo (HMO)

Scoring cheap one-way American Airlines flights from STL to HMO from $285 on Expedia couldn't be simpler --- just filter by "Price (lowest to highest)." Or check out our affordable return fares from $620 for your next getaway.**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.

To discover cheap flights from STL to HMO with American Airlines, start your search about one month before your planned departure. You can save 17% when you lock in your international tickets 18 to 29 days ahead instead of booking four to five months in advance. Another good tip? Booking on Sunday can lead to average savings of 17% compared to Friday (the most expensive day).**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 American Airlines's earliest flights from STL to HMO by selecting our "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.