Seattle to San Francisco

What the Data Says About SEA to SFO

The Seattle to San Francisco corridor (SEA → SFO) covers roughly 679 miles and is served by 26 carriers, based on Bureau of Transportation Statistics reporting. Across 37,651 flights in the dataset, this route posts a 79.1% on-time rate with an average delay of 61.9 minutes when flights run late. Over the most recent 24 months of BTS data, 13,522 flights were recorded on this pairing — 154 cancelled (1.1%) and 5 diverted (0.0%). Those baseline metrics tell you what to expect before you book.

Having 26 carriers on the route matters: more carriers generally means more daily schedule options, competitive pricing, and redundancy when flights are cancelled. With 37,651 total flights analyzed, the 79.1% 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, Jan 2025 posted the best performance on this corridor at 87% on-time, while Apr 2024 came in at 50% on-time — a 37-point gap between best and worst recent month. For travelers evaluating the SEA to SFO route, the combination of a 79.1% on-time rate, 61.9-minute average delay, 1.1% recent cancellation rate, and 26 available carriers is the concrete summary of what BTS data shows about reliability on this pairing.