$91 Cheap United flights Washington (IAD) to Phoenix (PHX)

You can discover affordable round-trip United Airlines flights from $181 from IAD to PHX by organizing your results from "Price (lowest to highest)" on Expedia. Or look for bargains from $91 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.

To find cheap United Airlines fares from Washington Dulles Intl. Airport (IAD) to Sky Harbor Intl. Airport (PHX), start searching one to three months before your intended departure. Securing domestic flights 34 to 86 days in advance could save you 25% compared to booking just 6 to 12 days ahead. The day you book can also affect the overall price. Sunday is usually the most affordable, while Monday is often the most expensive for domestic flights. You can save 6% on average by booking on a Sunday.**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 first flight from IAD to PHX with United Airlines departs at 12:50PM UTC-5. You'll touch down at 3:59PM UTC-7. The last United Airlines flight of the day takes off at 5:45PM UTC-5 and arrives at 8:54PM UTC-7. With 20% fewer cancellations for morning and mid-morning departures, jetting out early is typically the best choice.**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.

Depart from IAD to PHX with United Airlines and look forward to a range of perks including a rewarding loyalty program. When you book through Expedia as a United Mileage Plus and One Key™ member, you could also earn OneKeyCash™* to spend on select future travel purchases.*OneKeyCash™ disclaimer - OneKeyCash™ is not redeemable for cash and can only be used on Expedia, Hotels.com and Vrbo.