Bellingham to Seattle

What the Data Says About BLI to SEA

The Bellingham to Seattle corridor (BLI → SEA) covers roughly 93 miles and is served by 2 carriers, based on Bureau of Transportation Statistics reporting. Across 5,955 flights in the dataset, this route posts a 84.5% on-time rate with an average delay of 64.5 minutes when flights run late. Over the most recent 24 months of BTS data, 2,324 flights were recorded on this pairing — 31 cancelled (1.3%) and 2 diverted (0.1%). Those baseline metrics tell you what to expect before you book.

Having 2 carriers on the route matters: more carriers generally means more daily schedule options, competitive pricing, and redundancy when flights are cancelled. With 5,955 total flights analyzed, the 84.5% on-time figure is statistically meaningful rather than a small-sample fluke. The 64.5-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 2025 posted the best performance on this corridor at 92% on-time, while Sep 2024 came in at 54% on-time — a 38-point gap between best and worst recent month. For travelers evaluating the BLI to SEA route, the combination of a 84.5% on-time rate, 64.5-minute average delay, 1.3% recent cancellation rate, and 2 available carriers is the concrete summary of what BTS data shows about reliability on this pairing.