Boise to Seattle

What the Data Says About BOI to SEA

The Boise to Seattle corridor (BOI → SEA) covers roughly 399 miles and is served by 8 carriers, based on Bureau of Transportation Statistics reporting. Across 24,617 flights in the dataset, this route posts a 86.9% on-time rate with an average delay of 61.9 minutes when flights run late. Over the most recent 24 months of BTS data, 7,470 flights were recorded on this pairing — 21 cancelled (0.3%) and 10 diverted (0.1%). Those baseline metrics tell you what to expect before you book.

Having 8 carriers on the route matters: more carriers generally means more daily schedule options, competitive pricing, and redundancy when flights are cancelled. With 24,617 total flights analyzed, the 86.9% on-time figure is statistically meaningful rather than a small-sample fluke. The 61.9-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, Mar 2024 posted the best performance on this corridor at 91% on-time, while Jan 2024 came in at 70% on-time — a 22-point gap between best and worst recent month. For travelers evaluating the BOI to SEA route, the combination of a 86.9% on-time rate, 61.9-minute average delay, 0.3% recent cancellation rate, and 8 available carriers is the concrete summary of what BTS data shows about reliability on this pairing.