Denver to Ontario

What the Data Says About DEN to ONT

The Denver to Ontario corridor (DEN → ONT) covers roughly 819 miles and is served by 13 carriers, based on Bureau of Transportation Statistics reporting. Across 14,378 flights in the dataset, this route posts a 75.1% on-time rate with an average delay of 58.2 minutes when flights run late. Over the most recent 24 months of BTS data, 5,723 flights were recorded on this pairing — 32 cancelled (0.6%) and 5 diverted (0.1%). Those baseline metrics tell you what to expect before you book.

Having 13 carriers on the route matters: more carriers generally means more daily schedule options, competitive pricing, and redundancy when flights are cancelled. With 14,378 total flights analyzed, the 75.1% on-time figure is statistically meaningful rather than a small-sample fluke. The 58.2-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, Oct 2024 posted the best performance on this corridor at 89% on-time, while Jul 2025 came in at 59% on-time — a 30-point gap between best and worst recent month. For travelers evaluating the DEN to ONT route, the combination of a 75.1% on-time rate, 58.2-minute average delay, 0.6% recent cancellation rate, and 13 available carriers is the concrete summary of what BTS data shows about reliability on this pairing.