Idaho Falls to Seattle

What the Data Says About IDA to SEA

The Idaho Falls to Seattle corridor (IDA → SEA) covers roughly 566 miles and is served by 2 carriers, based on Bureau of Transportation Statistics reporting. Across 602 flights in the dataset, this route posts a 79.4% on-time rate with an average delay of 69.8 minutes when flights run late. Over the most recent 24 months of BTS data, 602 flights were recorded on this pairing — 9 cancelled (1.5%) and 1 diverted (0.2%). 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 602 total flights analyzed, the 79.4% on-time figure is statistically meaningful rather than a small-sample fluke. The 69.8-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 2025 posted the best performance on this corridor at 83% on-time, while Dec 2025 came in at 75% on-time — a 8-point gap between best and worst recent month. For travelers evaluating the IDA to SEA route, the combination of a 79.4% on-time rate, 69.8-minute average delay, 1.5% recent cancellation rate, and 2 available carriers is the concrete summary of what BTS data shows about reliability on this pairing.