Cheap Frontier Airlines flights Harlingen (HRL) to Denver (DEN)

You can discover cheap return Frontier Airlines flights from HRL to DEN by filtering your results from “Price (lowest to highest)” on Expedia. Or look for options 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.

January is one of the least expensive months to jet away to Denver with Frontier Airlines. You could also find great prices on one-way and return fares in November.

Search for affordable Frontier Airlines flights from Valley Intl. Airport (HRL) to Denver Intl. Airport (DEN) one to three months prior to your departure day. 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. Regardless of fare class and journey, the best day to book a domestic flight is usually Sunday and the most expensive is typically Monday. Passengers who book on a Sunday can save 6% on average compared to those who book 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.

To find out if there’s a direct route from HRL to DEN with Frontier Airlines or any other carriers, check the “Nonstop” filter when searching for tickets.

To find the earliest departures from HRL to DEN with Frontier Airlines, filter your results by “Morning” and “Early Morning.” Choosing an early flight usually means you’re 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.

Frontier Airlines flights from Valley Intl. Airport (HRL) to Denver land at Denver Intl. Airport (DEN). This is the main entry point here.

A rewarding loyalty program and the chance to rack up points through Frontier Miles are the start of the reasons to depart from HRL to DEN with Frontier Airlines. Plus, when you sign up to our One Key™ program, you can earn OneKeyCash™* alongside any airline 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.

Depending on the type of ticket you purchased, a fee may apply if you change or cancel your flight more than 24 hours after it has been confirmed. To secure flexible plane tickets, select our “No cancel fee” or “Changes included” filter when searching for flights. To learn more about changing or canceling your reservation, visit “Trips,” select your flight and tick “Manage Booking.”