About 1 in 3 F9 1204 flights from Miami arrived 15+ minutes late, diverted or cancelled over the past year (39%); 4.3% were cancelled. The typical flight landed 3 minutes late.
F9 1204: MIA → PHL
Scheduled to leave Miami at 9:21 p.m. local time. Over the past year it arrived on time 61% of the time (184 flights), in line with other F9 flights on the route at that hour (60%). Last seen in the data Aug 31, 2026.
Month by month
By day of week
| Day | Flights | On time |
|---|---|---|
| Monday | 30 | 57% |
| Tuesday | 16 | — |
| Wednesday | 12 | — |
| Thursday | 30 | 67% |
| Friday | 33 | 73% |
| Saturday | 25 | 48% |
| Sunday | 38 | 58% |
Why it was late
All flights MIA → PHL · Connecting off F9 1204? Check the risk
Questions
How often is F9 1204 from MIA to PHL late?
Frontier Airlines 1204 from Miami, FL to Philadelphia, PA arrived 15 or more minutes late, was diverted or was cancelled on 39% of 184 scheduled flights between September 2025 and August 2026. 4.3% 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.