Flight number record
F9 1280
Frontier Airlines · Denver to Miami
- Route
- DEN → MIA
- Departs
- 23:40
- Flights
- 264
- Period
- September 2025 to August 2026
Historical statistics for September 2025 to August 2026, not live status. For today’s F9 1280, check with Frontier Airlines.
F9 1280 sits in the middle of the pack with a B+. Close to three flights in four arrive on time by the DOT's definition, 2 points worse than the national rate of 77.3%. The late ones land about an hour behind schedule. That rests on 264 flights, with a median arrival 7 minutes early.
Key figures
On time
75.3%
Arrivals under 15 minutes late, of 263 completed flights
Avg delay
62 min
Across delayed arrivals only, not all flights
Cancelled
0.38%
National rate is 1.89%
1 hour+ late
8.0%
National rate is 8.3%
These figures cover 264 flights between September 2025 and August 2026. Beyond the headline rate, 8.0% of arrivals land a full hour or more behind schedule, against 8.3% nationally.
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Schedule
When F9 1280 flies
F9 1280 flies DEN to MIA without a single fixed slot. Its most common scheduled departure was 23:40, used on 79 of 264 flights, with 23:49 (37 flights) and 23:25 (36 flights) next.
- Departs 23:4079 flights29.9%
- Departs 23:4937 flights14.0%
- Departs 23:2536 flights13.6%
Scale runs 0% to 100%.
Share of scheduled departures at each local time. Times used on fewer than one flight in ten are not listed.
A 23:40 departure sits in the 8pm–5am window. Across every US flight scheduled in that window the on-time rate is 70.1%, and F9 1280 runs 5 points better at 75.3%. By that time of day most aircraft have flown several legs already, and whatever went wrong earlier is still in the schedule.
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Against the route
F9 1280 next to DEN to MIA
Every carrier on DEN to MIA combined arrived on time 74.9% of the time across 2,443 flights, so F9 1280 is about level with it. Across its whole network Frontier Airlines managed 72.7%, which this flight beats by 3 points.
| Compared with | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| F9 1280thin sample | 264 | 75.3% | 62 min | 0.38% | B+ |
| All Frontier Airlines on DEN–MIAthin sample | 353 | 73.9% | 63 min | 0.28% | C+ |
| All carriers on DEN–MIA | 2,443 | 74.9% | 70 min | 0.49% | C+ |
| Frontier Airlines, whole network | 213,022 | 72.7% | 84 min | 2.05% | C |
Across the year
F9 1280 quarter by quarter
F9 1280 did not run the same all year. Its best quarter was Apr–Jun 2026 at 85.6% on time and its weakest Jul–Sep 2026 at 66.1%, a swing of 20 points on roughly 66 flights a quarter. The twelve-month rate averages over that, so if you are flying in a weak quarter the quarter's own figure is the better guide.
- Oct–Dec 202545 flights66.7%
- Jan–Mar 202667 flights75.8%
- Apr–Jun 202690 flights85.6%
- Jul–Sep 202662 flights66.1%
Scale runs 60% to 90%.
By weekday, F9 1280 did best on Thursday at 89.2% on time and worst on Friday at 67.5%. Each day rests on about 38 flights, so a gap of 22 points is worth noticing but could still narrow in another year.
Arrival by arrival
How late F9 1280 runs when it is late
F9 1280 often beats the schedule: 94 of 263 completed flights, 36%, arrived 15 minutes or more early. The 65 late arrivals split 20 under half an hour, 24 between 30 and 60 minutes, and 21 an hour or more.
- 15+ min early94 flights35.7%
- Within 15 min104 flights39.5%
- 15–29 min late20 flights7.6%
- 30–59 min late24 flights9.1%
- 1–2 hours late15 flights5.7%
- 2+ hours late6 flights2.3%
Scale runs 0% to 100%.
Share of 263 completed flights by arrival against schedule.
16 of 72 late departures made up the time and arrived on time, 22% of them. 9 flights left on time and still arrived late.
The worst days
Worst days for F9 1280
The latest arrival of the period was on 1 December 2025, 7 hours 52 minutes behind schedule; most of its delay minutes were filed as carrier-caused (crew, maintenance, fuelling, baggage). The same cause led on three of the five worst days.
| Date | Arrived late by | Largest filed cause |
|---|---|---|
| 1 December 2025 | 7 hours 52 minutes | Carrier |
| 19 May 2026 | 3 hours 54 minutes | Carrier |
| 6 March 2026 | 3 hours 33 minutes | Late-arriving aircraft |
| 13 August 2026 | 2 hours 44 minutes | Carrier |
| 14 August 2026 | 2 hours 34 minutes | Late-arriving aircraft |
Delay causes
Why F9 1280 runs late
Carrier accounts for 56% of the 4,013 delay minutes carriers reported here, and the remaining four split what is left.
- 56%Carrier
- 31%Late-arriving aircraft
- 9%National Airspace System
- 4%Extreme weather
The largest share of delay minutes, 56%, falls under carrier control: crew scheduling, maintenance, fuelling, baggage. It accounts for 2,242 of the 4,013 delay minutes reported here. The split is drawn from 4,013 delay minutes reported on F9 1280.
Cancellations are rare at 0.38%, below the national 1.89% and low enough to earn the plus on the grade. Roughly one flight in 100 is called off; the risk here is arriving late, not not arriving.
Connections and routes
What a delay on this flight costs
8.0% of arrivals land an hour or more late, close to the national 8.3%, so a 60 to 75 minute layover is reasonable here while anything under 45 minutes is a bet. Most delays on this route last about an hour, which a normal layover absorbs.
At 1,709 miles this is transcontinental flying, and long routes get a quiet structural advantage. Scheduled block time on a flight this length carries more padding in absolute minutes, so a twenty-minute late departure often still becomes an on-time arrival. Read the on-time rate here as slightly flattering next to a short-haul route with the same operational quality.
Every one of the 264 flights under F9 1280 in the data flew DEN to MIA. The number was not reused on any other city pair, which makes this a clean record of one route.
One caution: this is a thin sample. 264 flights over twelve months is enough to clear this site's floor but not enough to pin the rate down tightly, and a single bad week moves it by more than a point. Treat the grade as a rough reading.
What to do with this
Booking F9 1280
For a booking, read F9 1280 as 75.3% on time with 0.38% cancelled over 264 flights. Those are rates from the past twelve months, not a forecast for any particular day.
Related
Where to go next
- DEN to MIA, every carrier and departure
- MIA to DEN, the return direction
- Denver International (DEN) delay statistics
- Miami International (MIA) delay statistics
- Frontier Airlines on-time record
- Every Frontier Airlines flight number with a record
- The most and least reliable flight numbers in the US
- Worst months to fly in the US, ranked by the data
A flight number here means Frontier Airlines’s own number as it reports to the DOT. How the figures are computed is on the methodology page.
Source: US DOT Bureau of Transportation Statistics, on-time performance data, September 2025 to August 2026. Last updated ; recomputed monthly. How this data is collected.