How often are IAD to DEN flights on time?

Flights from Washington (IAD) to Denver (DEN) arrive on time 89% of the time across 19,079 flights of official data.

Which airline is most reliable on the IAD to DEN route?

United Airlines has the best on-time record on this route at 90% across 14,575 flights.

Route reliability

Flights from Washington to Denver arrive on time 89% of the time across 19,079 flights. Here’s how each airline really performs.

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On-time rate

19,079 flights

Airline	On-time	Flights
United Airlines	90%	14,575
Southwest Airlines	88%	4,504

On-time = arrived within 15 minutes of schedule, per BTS TranStats. Compare the reverse leg DEN → IAD.

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Score real IAD–DEN flights on reliability, weather, and connection safety — not just price.

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