$115 Cheap United flights Washington (IAD) to Colorado Springs (COS)

Make use of the "Price (lowest to highest)" filter on Expedia to find cheap United Airlines return flights from $229 from IAD to COS. Affordable one-way tickets from $115 are also on offer.**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 United Airlines flights from Washington Dulles Intl. Airport (IAD) to Colorado Springs Airport (COS) 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. No matter the fare class and itinerary, the best day of the week to book a domestic flight is generally Sunday and the most expensive 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.

To find the earliest departures from IAD to COS with United Airlines, filter your search by "Early Morning" and "Morning." Booking an early flight generally 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.

A rewarding loyalty program and the ability to collect points through United Mileage Plus are the start of the reasons to jet off from IAD to COS with United Airlines. Plus, when you join our One Key™ program, you can earn OneKeyCash™* in addition to any airline loyalty program earnings. It's yours to spend on future bookings.*OneKeyCash™ disclaimer - OneKeyCash™ is not redeemable for cash and can only be used on Expedia, Hotels.com and Vrbo.