$145 Cheap American Airlines flights Harlingen (HRL) to Seattle (SEA)

Set the "Price (lowest to highest)" filter on Expedia to look for cheap American Airlines round-trip flights from $222 from HRL to SEA. Affordable one-way fares from $145 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.

Look for affordable American Airlines flights from Valley Intl. Airport (HRL) to Seattle - Tacoma Intl. Airport (SEA) one to three months prior to your departure date. Travelers who book domestic flights 34 to 86 days in advance can save 25% compared to those who book just 6 to 12 days ahead. No matter the fare type and journey, the best day of the week to book a domestic flight is generally Sunday and the most expensive day is typically Monday. Passengers who book on a Sunday can save 6% on average compared to those who book their travel on a Monday.**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.

Search American Airlines's earliest flights from HRL to SEA by checking the "Morning" and "Early Morning" filters. Not only will you arrive at your destination sooner, early departures are also 20% less likely to be 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.