Washington to Denver

What the Data Says About IAD to DEN

The Washington to Denver corridor (IAD → DEN) covers roughly 1,452 miles and is served by 2 carriers, based on Bureau of Transportation Statistics reporting. Across 17,372 flights in the dataset, this route posts a 83.1% on-time rate with an average delay of 71.5 minutes when flights run late. Over the most recent 24 months of BTS data, 6,809 flights were recorded on this pairing — 64 cancelled (0.9%) and 31 diverted (0.5%). Those baseline metrics tell you what to expect before you book.

Having 2 carriers on the route matters: more carriers generally means more daily schedule options, competitive pricing, and redundancy when flights are cancelled. With 17,372 total flights analyzed, the 83.1% on-time figure is statistically meaningful rather than a small-sample fluke. The 71.5-minute average delay applies only to flights that actually ran late, so it is not the average wait across all departures — the majority of flights on this route depart on time under the BTS definition of a delay (15+ minutes past schedule).

Looking at recent months, Nov 2025 posted the best performance on this corridor at 91% on-time, while Jul 2025 came in at 69% on-time — a 22-point gap between best and worst recent month. For travelers evaluating the IAD to DEN route, the combination of a 83.1% on-time rate, 71.5-minute average delay, 0.9% recent cancellation rate, and 2 available carriers is the concrete summary of what BTS data shows about reliability on this pairing.