Washington to St. Louis

What the Data Says About DCA to STL

The Washington to St. Louis corridor (DCA → STL) covers roughly 719 miles and is served by 25 carriers, based on Bureau of Transportation Statistics reporting. Across 12,058 flights in the dataset, this route posts a 80.7% on-time rate with an average delay of 68.6 minutes when flights run late. Over the most recent 24 months of BTS data, 4,650 flights were recorded on this pairing — 101 cancelled (2.2%) and 5 diverted (0.1%). Those baseline metrics tell you what to expect before you book.

Having 25 carriers on the route matters: more carriers generally means more daily schedule options, competitive pricing, and redundancy when flights are cancelled. With 12,058 total flights analyzed, the 80.7% on-time figure is statistically meaningful rather than a small-sample fluke. The 68.6-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, Oct 2024 posted the best performance on this corridor at 88% on-time, while Jul 2025 came in at 63% on-time — a 25-point gap between best and worst recent month. For travelers evaluating the DCA to STL route, the combination of a 80.7% on-time rate, 68.6-minute average delay, 2.2% recent cancellation rate, and 25 available carriers is the concrete summary of what BTS data shows about reliability on this pairing.