How often are DEN to IAD flights on time?

Flights from Denver (DEN) to Washington (IAD) arrive on time 85% of the time across 18,837 flights of official data.

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

United Airlines has the best on-time record on this route at 88% across 14,339 flights.

Route reliability

Flights from Denver to Washington arrive on time 85% of the time across 18,837 flights. Here’s how each airline really performs.

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On-time rate

18,837 flights

Airline	On-time	Flights
United Airlines	88%	14,339
Southwest Airlines	75%	4,498

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

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