Seattle to San Diego

What the Data Says About SEA to SAN

The Seattle to San Diego corridor (SEA → SAN) covers roughly 1,050 miles and is served by 14 carriers, based on Bureau of Transportation Statistics reporting. Across 25,263 flights in the dataset, this route posts a 83% on-time rate with an average delay of 53.9 minutes when flights run late. Over the most recent 24 months of BTS data, 9,155 flights were recorded on this pairing — 112 cancelled (1.2%) and 29 diverted (0.3%). Those baseline metrics tell you what to expect before you book.

Having 14 carriers on the route matters: more carriers generally means more daily schedule options, competitive pricing, and redundancy when flights are cancelled. With 25,263 total flights analyzed, the 83% on-time figure is statistically meaningful rather than a small-sample fluke. The 53.9-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 84% on-time, while Dec 2025 came in at 69% on-time — a 15-point gap between best and worst recent month. For travelers evaluating the SEA to SAN route, the combination of a 83% on-time rate, 53.9-minute average delay, 1.2% recent cancellation rate, and 14 available carriers is the concrete summary of what BTS data shows about reliability on this pairing.