Washington to Houston

What the Data Says About IAD to IAH

The Washington to Houston corridor (IAD → IAH) covers roughly 1,190 miles and is served by 3 carriers, based on Bureau of Transportation Statistics reporting. Across 10,000 flights in the dataset, this route posts a 82% on-time rate with an average delay of 69.9 minutes when flights run late. Over the most recent 24 months of BTS data, 3,619 flights were recorded on this pairing — 33 cancelled (0.9%) and 9 diverted (0.2%). Those baseline metrics tell you what to expect before you book.

Having 3 carriers on the route matters: more carriers generally means more daily schedule options, competitive pricing, and redundancy when flights are cancelled. With 10,000 total flights analyzed, the 82% on-time figure is statistically meaningful rather than a small-sample fluke. The 69.9-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, Sep 2025 posted the best performance on this corridor at 92% on-time, while Jul 2024 came in at 65% on-time — a 28-point gap between best and worst recent month. For travelers evaluating the IAD to IAH route, the combination of a 82% on-time rate, 69.9-minute average delay, 0.9% recent cancellation rate, and 3 available carriers is the concrete summary of what BTS data shows about reliability on this pairing.