$105 Cheap United flights Detroit (DTW) to Harlingen (HRL)

Landing cheap one-way United Airlines flights from DTW to HRL from $105 on Expedia is a cinch — just filter by "Price (lowest to highest)." Or check out our affordable return fares from $230 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.

Start searching one to three months ahead of your travel date to find cheaper fares on United Airlines flights from Detroit Metropolitan Wayne County Airport (DTW) to Valley Intl. Airport (HRL). 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.

Sort your results by "Morning" and "Early Morning" to see the earliest departures from DTW to HRL. Setting off early means flight cancellations are less likely.**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.

A rewarding loyalty program and the chance to rack up points through United Mileage Plus are the start of the reasons to leave from DTW to HRL with United Airlines. Plus, by joining Expedia's free One Key™ program, you can earn OneKeyCash™* on top of United Airlines's loyalty program earnings. It's yours to spend on future travel plans.*OneKeyCash™ disclaimer - OneKeyCash™ is not redeemable for cash and can only be used on Expedia, Hotels.com and Vrbo.