Billings to Seattle

What the Data Says About BIL to SEA

The Billings to Seattle corridor (BIL → SEA) covers roughly 664 miles and is served by 1 carrier, based on Bureau of Transportation Statistics reporting. Across 1,691 flights in the dataset, this route posts a 84.2% on-time rate with an average delay of 69.7 minutes when flights run late. Over the most recent 24 months of BTS data, 1,691 flights were recorded on this pairing — 26 cancelled (1.5%) and 7 diverted (0.4%). Those baseline metrics tell you what to expect before you book.

Having 1 carrier on the route matters: more carriers generally means more daily schedule options, competitive pricing, and redundancy when flights are cancelled. With 1,691 total flights analyzed, the 84.2% on-time figure is statistically meaningful rather than a small-sample fluke. The 69.7-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 2021 posted the best performance on this corridor at 94% on-time, while Feb 2021 came in at 59% on-time — a 34-point gap between best and worst recent month. For travelers evaluating the BIL to SEA route, the combination of a 84.2% on-time rate, 69.7-minute average delay, 1.5% recent cancellation rate, and 1 available carrier is the concrete summary of what BTS data shows about reliability on this pairing.