Flight number record

F9 1815

Frontier Airlines · Austin to Denver

Route: AUS → DEN
Departs: 06:45
Flights: 308
Period: July 2025 to June 2026

Historical statistics for July 2025 to June 2026, not live status. For today’s F9 1815, check with Frontier Airlines.

F9 1815 earns an A+. More than four flights in five arrive inside the 15-minute window the DOT uses to define an on-time arrival, which puts it 9 points better than the national rate of 77.6%. When something does go wrong the average delay runs an hour and a half. That rests on 308 flights, with a median arrival 10 minutes early.

Set against the rest of the country, F9 1815's record is 9 points better than the US average of 77.6%. That gap is worth roughly 86 fewer late arrivals for every thousand flights.

On time

86.2%

Arrivals under 15 minutes late, of 305 completed flights

Avg delay

91 min

Across delayed arrivals only, not all flights

Cancelled

0.65%

National rate is 1.81%

1 hour+ late

4.6%

National rate is 8.1%

These figures cover 308 flights between July 2025 and June 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.

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 06:00 (66 flights) and 06:30 (41 flights) next. Carriers retime flights through the season, so the rates here blend slightly different positions in the aircraft's day.

Departs 06:4591 flights29.5%
Departs 06:0066 flights21.4%
Departs 06:3041 flights13.3%

Scale runs 0% to 100%. Rows with fewer than 30 flights show a dash.

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 3 points worse at 86.2%. Early departures usually start with an aircraft that has not flown yet that day, which is most of why the window does well.

Against the route

F9 1815 next to AUS to DEN

Every carrier on AUS to DEN combined arrived on time 78.4% of the time across 5,310 flights, so F9 1815 is 8 points ahead of it. Frontier flew 549 flights on the same city pair under all its flight numbers, including this one, and those ran 84.8% on time. Across its whole network Frontier Airlines managed 73.2%, which this flight beats by 13 points.

F9 1815 against its route and carrier
Compared with	Flights	On time	Avg delay	Cancelled	Grade
F9 1815thin sample	308	86.2%	91 min	0.65%	A+
All Frontier Airlines on AUS–DEN	549	84.8%	92 min	0.55%	B+
All carriers on AUS–DEN	5,310	78.4%	63 min	0.81%	B+
Frontier Airlines, whole network	205,332	73.2%	84 min	1.85%	C

Across the year

F9 1815 quarter by quarter

Quarter by quarter F9 1815 held fairly steady: 83.5% in Jul–Sep 2025, 90.2% in Oct–Dec 2025, 85.2% in Jan–Mar 2026 and 85.3% in Apr–Jun 2026. A spread of 7 points is about what a sample of this size moves on its own, so the annual figure is a fair summary.

Jul–Sep 202592 flights83.5%
Oct–Dec 202592 flights90.2%
Jan–Mar 202690 flights85.2%
Apr–Jun 202634 flights85.3%

Scale runs 75% to 95%. Rows with fewer than 30 flights show a dash.

By weekday, F9 1815 did best on Tuesday at 93.2% on time and worst on Monday at 75.0%. Each day rests on about 44 flights, so a gap of 18 points is worth noticing but could still narrow in another year.

Delay causes

Why F9 1815 runs late

One category carries most of the weight here. Carrier accounts for 82% of the 3,836 delay minutes carriers reported, and the remaining four split what is left. The split is by minutes rather than by flights, so a few very long delays count for as much as many short ones.

Carrier
82%
National Airspace System
12%
Late-arriving aircraft
7%

The largest share of delay minutes, 82%, falls under carrier control: crew scheduling, maintenance, fuelling, baggage. Unlike weather, that is a management outcome, and it is the category where the gap between two carriers on the same schedule is genuinely earned. It accounts for 3,137 of the 3,836 delay minutes reported here. The split is drawn from 3,836 delay minutes reported on F9 1815.

Cancellations are rare at 0.65%, below the national 1.81% 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 8.1% 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. It is also long enough that the aircraft usually flies three or four legs a day rather than six, which slows how fast delay compounds.

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: 86.2% on time and 0.65% cancelled. That is a base rate, not a promise about any single day.

Where to go next

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, July 2025 to June 2026. Last updated 15 September 2026; recomputed monthly. How this data is collected.

Key figures