San Francisco to Ontario

What the Data Says About SFO to ONT

The San Francisco to Ontario corridor (SFO → ONT) covers roughly 363 miles and is served by 12 carriers, based on Bureau of Transportation Statistics reporting. Across 8,471 flights in the dataset, this route posts a 84.3% on-time rate with an average delay of 73.5 minutes when flights run late. Over the most recent 24 months of BTS data, 2,841 flights were recorded on this pairing — 33 cancelled (1.2%) and 3 diverted (0.1%). Those baseline metrics tell you what to expect before you book.

Having 12 carriers on the route matters: more carriers generally means more daily schedule options, competitive pricing, and redundancy when flights are cancelled. With 8,471 total flights analyzed, the 84.3% on-time figure is statistically meaningful rather than a small-sample fluke. The 73.5-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, Apr 2025 posted the best performance on this corridor at 92% on-time, while Nov 2025 came in at 69% on-time — a 24-point gap between best and worst recent month. For travelers evaluating the SFO to ONT route, the combination of a 84.3% on-time rate, 73.5-minute average delay, 1.2% recent cancellation rate, and 12 available carriers is the concrete summary of what BTS data shows about reliability on this pairing.