Ontario to Denver

What the Data Says About ONT to DEN

The Ontario to Denver corridor (ONT → DEN) covers roughly 819 miles and is served by 12 carriers, based on Bureau of Transportation Statistics reporting. Across 14,321 flights in the dataset, this route posts a 84% on-time rate with an average delay of 72.2 minutes when flights run late. Over the most recent 24 months of BTS data, 5,702 flights were recorded on this pairing — 39 cancelled (0.7%) and 17 diverted (0.3%). 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 14,321 total flights analyzed, the 84% on-time figure is statistically meaningful rather than a small-sample fluke. The 72.2-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, Sep 2024 posted the best performance on this corridor at 90% on-time, while Jul 2025 came in at 66% on-time — a 25-point gap between best and worst recent month. For travelers evaluating the ONT to DEN route, the combination of a 84% on-time rate, 72.2-minute average delay, 0.7% recent cancellation rate, and 12 available carriers is the concrete summary of what BTS data shows about reliability on this pairing.