$78 Cheap United flights Houston (IAH) to Harlingen (HRL)

Finding cheap one-way United Airlines flights from IAH to HRL from $78 on Expedia is a breeze — just filter by "Price (lowest to highest)." Or check out our affordable return fares from $155 for your next adventure.**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 cheap United Airlines flights from George Bush Intercontinental Airport (IAH) to Valley Intl. Airport (HRL) one to three months prior to your day of departure. 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 class and journey, the best day to book a domestic flight is generally Sunday and the most expensive tends to be 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.

The earliest flight from IAH to HRL with United Airlines leaves at 9:45AM UTC-6. You'll touch down at 11:19AM UTC-6. The last United Airlines flight of the day leaves at 10:15PM UTC-6 and arrives at 11:36PM UTC-6. With around 20% fewer cancellations for early and mid-morning flights, jetting out early is usually the best option.**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.

With a rewarding loyalty program, United Airlines is a favorite of many passengers flying from IAH to HRL. Plus, as 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.