Flight number record
F9 1815
Frontier Airlines · Austin to Denver
- Route
- AUS → DEN
- Departs
- 06:45
- Flights
- 308
- Period
- September 2025 to August 2026
Historical statistics for September 2025 to August 2026, not live status. For today’s F9 1815, check with Frontier Airlines.
F9 1815 earns an A+. Close to nine flights in ten arrive inside the 15-minute window the DOT uses to define an on-time arrival, which puts it 11 points better than the national rate of 77.3%. When something does go wrong the average delay runs about an hour. That rests on 308 flights, with a median arrival 10 minutes early.
Set against the rest of the country, F9 1815's record is 11 points better than the US average of 77.3%. That gap is worth roughly 109 fewer late arrivals for every thousand flights.
Key figures
On time
88.2%
Arrivals under 15 minutes late, of 306 completed flights
Avg delay
63 min
Across delayed arrivals only, not all flights
Cancelled
0.32%
National rate is 1.89%
1 hour+ late
4.6%
National rate is 8.3%
These figures cover 308 flights between September 2025 and August 2026. The median arrival is 10 minutes early, which is the part an average hides: most flights here are fine, and the on-time rate is decided by a tail of badly late ones. On-time means under 15 minutes late, the DOT's own threshold.
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Schedule
When F9 1815 flies
F9 1815 flies AUS to DEN without a single fixed slot. Its most common scheduled departure was 06:45, used on 91 of 308 flights, with 06:30 (89 flights) and 06:00 (31 flights) next.
- Departs 06:4591 flights29.5%
- Departs 06:3089 flights28.9%
- Departs 06:0031 flights10.1%
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 06:45 departure sits in the 5am–8am window. Across every US flight scheduled in that window the on-time rate is 89.3%, and F9 1815 runs level with that at 88.2%. Early departures usually start with an aircraft that has not flown yet that day, which is most of why the window does well.
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Against the route
F9 1815 next to AUS to DEN
Every carrier on AUS to DEN combined arrived on time 78.9% of the time across 5,509 flights, so F9 1815 is 9 points ahead of it. Frontier flew 606 flights on the same city pair under all its flight numbers, including this one, and those ran 83.3% on time. Across its whole network Frontier Airlines managed 72.7%, which this flight beats by 16 points.
| Compared with | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| F9 1815thin sample | 308 | 88.2% | 63 min | 0.32% | A+ |
| All Frontier Airlines on AUS–DEN | 606 | 83.3% | 76 min | 0.66% | B+ |
| All carriers on AUS–DEN | 5,509 | 78.9% | 63 min | 0.64% | B+ |
| Frontier Airlines, whole network | 213,022 | 72.7% | 84 min | 2.05% | C |
Across the year
F9 1815 quarter by quarter
Quarter by quarter F9 1815 held fairly steady: 93.3% in Jul–Sep 2025, 90.2% in Oct–Dec 2025, 85.2% in Jan–Mar 2026, 85.3% in Apr–Jun 2026 and 88.7% in Jul–Sep 2026. A spread of 8 points is about what a sample of this size moves on its own, so the annual figure is a fair summary.
- Jul–Sep 202530 flights93.3%
- Oct–Dec 202592 flights90.2%
- Jan–Mar 202690 flights85.2%
- Apr–Jun 202634 flights85.3%
- Jul–Sep 202662 flights88.7%
Scale runs 75% to 100%.
By weekday, F9 1815 did best on Sunday at 100.0% on time and worst on Monday at 77.8%. Each day rests on about 44 flights, so a gap of 22 points is worth noticing but could still narrow in another year.
Arrival by arrival
How late F9 1815 runs when it is late
F9 1815 often beats the schedule: 112 of 306 completed flights, 37%, arrived 15 minutes or more early. The 36 late arrivals split 14 under half an hour, 8 between 30 and 60 minutes, and 14 an hour or more.
- 15+ min early112 flights36.6%
- Within 15 min158 flights51.6%
- 15–29 min late14 flights4.6%
- 30–59 min late8 flights2.6%
- 1–2 hours late9 flights2.9%
- 2+ hours late5 flights1.6%
Scale runs 0% to 100%.
Share of 306 completed flights by arrival against schedule.
Time lost at the gate mostly stays lost. Of 27 departures that left 15 minutes late or more, only 2 made it up before arrival. 11 flights left on time and still arrived late.
The worst days
Worst days for F9 1815
The latest arrival of the period was on 26 January 2026, 4 hours 50 minutes behind schedule; most of its delay minutes were filed as carrier-caused (crew, maintenance, fuelling, baggage). The same cause led on five of the five worst days.
| Date | Arrived late by | Largest filed cause |
|---|---|---|
| 26 January 2026 | 4 hours 50 minutes | Carrier |
| 15 June 2026 | 3 hours 14 minutes | Carrier |
| 21 February 2026 | 2 hours 59 minutes | Carrier |
| 30 October 2025 | 2 hours 32 minutes | Carrier |
| 22 July 2026 | 2 hours 23 minutes | Carrier |
Delay causes
Why F9 1815 runs late
Carrier accounts for 78% of the 2,259 delay minutes carriers reported here, and the remaining four split what is left.
- 78%Carrier
- 18%National Airspace System
- 4%Late-arriving aircraft
The largest share of delay minutes, 78%, falls under carrier control: crew scheduling, maintenance, fuelling, baggage. It accounts for 1,768 of the 2,259 delay minutes reported here. The split is drawn from 2,259 delay minutes reported on F9 1815.
Cancellations are rare at 0.32%, 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
Badly late arrivals are rare here: only 4.6% land an hour or more behind schedule, against 8.3% nationally. Connections built on this flight are about as safe as US domestic connections get, though a cancelled flight still ignores every layover you give it.
The 775 miles between these two airports put this in the middle of the US network, around two and a half to three hours of block time. That is enough cruise to absorb a ten-minute late pushback and not enough to absorb thirty.
Every one of the 308 flights under F9 1815 in the data flew AUS to DEN. 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. 308 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 1815
For a booking, F9 1815 has one of the better records a US domestic flight can show: 88.2% on time and 0.32% cancelled. That is a base rate, not a promise about any single day.
Related
Where to go next
- AUS to DEN, every carrier and departure
- DEN to AUS, the return direction
- United Airlines 2447 on the same route82.2%
- United Airlines 595 on the same route89.0%
- United Airlines 779 on the same route92.8%
- Austin-Bergstrom International (AUS) delay statistics
- Denver International (DEN) 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
- The best time of day to fly, according to 7.05 million flight records
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.