Seattle to Chicago

What the Data Says About SEA to ORD

The Seattle to Chicago corridor (SEA → ORD) covers roughly 1,721 miles and is served by 14 carriers, based on Bureau of Transportation Statistics reporting. Across 27,905 flights in the dataset, this route posts a 82% on-time rate with an average delay of 71.8 minutes when flights run late. Over the most recent 24 months of BTS data, 10,390 flights were recorded on this pairing — 104 cancelled (1.0%) and 51 diverted (0.5%). Those baseline metrics tell you what to expect before you book.

Having 14 carriers on the route matters: more carriers generally means more daily schedule options, competitive pricing, and redundancy when flights are cancelled. With 27,905 total flights analyzed, the 82% on-time figure is statistically meaningful rather than a small-sample fluke. The 71.8-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 2024 posted the best performance on this corridor at 87% on-time, while Aug 2025 came in at 62% on-time — a 25-point gap between best and worst recent month. For travelers evaluating the SEA to ORD route, the combination of a 82% on-time rate, 71.8-minute average delay, 1.0% recent cancellation rate, and 14 available carriers is the concrete summary of what BTS data shows about reliability on this pairing.