About 1 in 9 F9 1500 flights from Ontario arrived 15+ minutes late, diverted or cancelled over the past year (11%); 0.9% were cancelled. The typical flight landed 11 minutes early.
F9 1500: ONT → DEN
Scheduled to leave Ontario at 6:00 a.m. local time. Over the past year it arrived on time 89% of the time (320 flights), in line with other F9 flights on the route at that hour (90%). Last seen in the data Aug 31, 2026.
Month by month
By day of week
| Day | Flights | On time |
|---|---|---|
| Monday | 48 | 88% |
| Tuesday | 46 | 87% |
| Wednesday | 45 | 91% |
| Thursday | 46 | 96% |
| Friday | 45 | 89% |
| Saturday | 45 | 87% |
| Sunday | 45 | 89% |
Why it was late
All flights ONT → DEN · Connecting off F9 1500? Check the risk
Questions
How often is F9 1500 from ONT to DEN late?
Frontier Airlines 1500 from Ontario, CA to Denver, CO arrived 15 or more minutes late, was diverted or was cancelled on 11% of 320 scheduled flights between September 2025 and August 2026. 0.9% were cancelled.
Flight numbers change. Figures cover flights with this airline, number and route only. "Likely range" is the 95% interval for the true on-time rate given the number of flights. This is history, not live status: check Frontier Airlines for today's flight. Method.