Airport month record

AUSSEP

Austin-Bergstrom International in September 2025

Departures: 6,889
Month: September 2025
National, same month: 83.4%
Carriers: 10

Historical statistics for September 2025, not live status or a forecast for this year’s September. For today’s conditions at AUS, see live FAA status.

AUS in September earns a B+. More than four flights in five arrive inside the 15-minute window the DOT uses to define an on-time arrival, which puts it about a point better than the national rate of 83.4%. When something does go wrong the average delay runs about an hour. That rests on 6,889 flights, of which Delta Air Lines flew 1,069 at 89.2% on time.

Delta Air Lines is the most reliable of the five carriers covered here at 89.2% on time across 1,069 flights.

On time

84.2%

Arrivals under 15 minutes late, of 6,852 completed departures

Avg delay

65 min

Across delayed arrivals only, not all flights

Cancelled

0.39%

Nationally in September: 0.51%

Whole year

76.6%

AUS across all twelve months

These figures cover 6,889 departures from Austin-Bergstrom International in September 2025. On time means an arrival less than 15 minutes after the scheduled gate time, the DOT's threshold, and the national comparison uses every US departure in the same month rather than the whole year.

Against the year

September next to AUS's other months

Against AUS's own year, September ran 8 points better than the twelve-month rate of 76.6%, which makes it the best of the twelve months in the data. Cancellations were unusually low for AUS in September, at 0.39% against 1.21% across the year. Either side of it, August ran 78.1% on time and October 76.8%, so a trip moved by a few weeks would have landed in a worse stretch.

AUS month by month
Month	Flights	On time	Avg delay	Cancelled	Grade
July 2025	7,896	69.6%	80 min	1.61%	C
August 2025	7,214	78.1%	74 min	0.94%	B+
September 2025 (this page)	6,889	84.2%	65 min	0.39%	B+
October 2025	7,845	76.8%	61 min	0.40%	B+
November 2025	7,346	76.0%	75 min	1.05%	B
December 2025	7,528	77.9%	70 min	0.62%	B+
January 2026	6,707	82.8%	84 min	4.65%	B−
February 2026	6,471	81.9%	68 min	0.99%	B+
March 2026	7,973	73.3%	73 min	1.71%	C
April 2026	7,647	77.5%	64 min	0.59%	B+
May 2026	7,831	75.1%	71 min	0.91%	B+
June 2026	7,879	69.1%	69 min	0.98%	C+

Departure window

The best time of day to leave AUS in September

Departure time matters more here than the choice of carrier. The gap between the best and worst window is 19 points, against 9 points between the best and worst carrier. Each bar is the on-time rate for flights scheduled inside that window.

5am–8am1,336 flights92.5%
8am–11am1,157 flights90.1%
11am–2pm1,213 flights84.0%
2pm–5pm1,378 flights82.6%
5pm–8pm1,290 flights76.0%
8pm–5am515 flights74.0%

Scale runs 65% to 100%. Rows with fewer than 30 flights show a dash.

Book the early departure. Flights leaving between 5am–8am arrive on time 92.5% of the time, against 74.0% for the overnight window. That is 19 points of difference for no extra money, and it comes from the same aircraft having had no earlier flight to fall behind on. The 2pm–5pm window is the busiest, with 1,378 flights scheduled in it.

Across the week, Tuesday is the strongest day at 89.8% on time and Friday the weakest at 80.1%. 10 points is a smaller lever than departure hour, but it is free.

Carrier by carrier

Which airlines ran best at AUS in September

The choice of carrier is not cosmetic here. Delta Air Lines arrives on time 89.2% of the time; American Airlines manages 80.0%. Sample sizes sit next to every figure, because a two-point gap across 820 flights means less than a ten-point one.

Carriers at AUS in September 2025
Airline	Flights	On time	Avg delay	Cancelled	Grade
Southwest Airlines	2,862	83.3%	45 min	0.10%	B+
Delta Air Lines	1,069	89.2%	74 min	0.28%	A+
United Airlines	914	85.1%	60 min	0.55%	A+
American Airlines	820	80.0%	131 min	1.22%	B
SkyWest Airlines	639	87.6%	60 min	0.47%	A+
Frontier Airlinesthin sample	179	78.0%	45 min	1.12%	B
Alaska Airlinesthin sample	179	87.2%	29 min	0.00%	A+
Envoy Airthin sample	99	85.7%	89 min	1.01%	A
Spirit Airlinesthin sample	57	84.2%	75 min	0.00%	B+
Allegiant Airthin sample	42	69.0%	45 min	0.00%	C+

Delta leads American by 9 points. Real, but small enough that a better departure time on the weaker carrier can outweigh it.

Route by route

Busiest routes out of AUS in September

Routes from AUS in September 2025
Route	Flights	On time	Avg delay	Cancelled	Grade
AUS to ATL · Atlanta	385	90.6%	54 min	0.00%	A+
AUS to DEN · Denver	377	81.8%	61 min	0.80%	B+
AUS to DFW · Dallas-Fort Worth	370	78.9%	113 min	2.43%	B
AUS to LAX · Los Angelesthin sample	270	91.1%	51 min	0.00%	A+
AUS to ORD · Chicagothin sample	258	77.4%	60 min	0.39%	B+
AUS to IAH · Houstonthin sample	237	77.1%	45 min	0.42%	B+
AUS to PHX · Phoenixthin sample	236	81.3%	87 min	1.69%	B
AUS to SFO · San Franciscothin sample	228	83.3%	49 min	0.00%	B+
AUS to BNA · Nashvillethin sample	228	86.4%	42 min	0.00%	A+
AUS to LAS · Las Vegasthin sample	218	75.5%	42 min	0.46%	B+
AUS to DAL · Dallasthin sample	189	87.2%	65 min	0.00%	A+
AUS to MSY · New Orleansthin sample	177	87.0%	44 min	0.00%	A+
AUS to SAN · San Diegothin sample	176	81.0%	60 min	1.14%	B
AUS to JFK · New Yorkthin sample	174	89.6%	87 min	0.00%	A+
AUS to SEA · Seattlethin sample	167	86.2%	58 min	0.00%	A+
AUS to EWR · Newarkthin sample	159	86.0%	95 min	0.63%	A+
AUS to MCO · Orlandothin sample	157	87.9%	45 min	0.00%	A+
AUS to BOS · Bostonthin sample	137	60.7%	89 min	1.46%	D
AUS to HOU · Houstonthin sample	136	77.2%	47 min	0.00%	B+
AUS to SLC · Salt Lake Citythin sample	135	91.1%	55 min	0.00%	A+
AUS to MSP · Minneapolisthin sample	133	90.8%	72 min	0.75%	A+
AUS to CLT · Charlottethin sample	128	85.8%	90 min	0.78%	A+
AUS to MIA · Miamithin sample	124	82.0%	81 min	0.81%	B+
AUS to DTW · Detroitthin sample	116	94.8%	175 min	0.00%	A+
AUS to PHL · Philadelphiathin sample	113	81.4%	233 min	0.00%	B+

Delay causes

What held AUS up in September

One category carries most of the weight here. Late-arriving aircraft accounts for 42% of the 70,000 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.

Late-arriving aircraft
42%
Carrier
29%
National Airspace System
26%
Extreme weather
3%
Security
0%

42% of delay minutes trace back to a late-arriving aircraft, meaning the plane was already behind before it got here. That is a cascade, and cascades start small and grow through the day. Across 70,000 reported delay minutes here, that single category outweighs weather by 13 to one. It is the strongest argument for booking the first departure of the morning, when the aircraft has been sitting at the gate overnight with nothing to inherit. The split is drawn from 70,319 reported delay minutes.

Cancellations are rare at 0.39%, below the national 0.51% 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.

Badly late arrivals are rare here: only 4.8% land an hour or more behind schedule, against 5.4% 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.

What to do with this

Flying from AUS in September

For a September trip through AUS: this is one of the better months to be flying from here, 84.2% on time with 0.39% cancelled. That is a base rate for the month as a whole; a single storm can still spoil a particular day.

Austin-Bergstrom International (AUS), the whole year
AUS in July69.6%
AUS in August78.1%
AUS in October76.8%
AUS in November76.0%
AUS in December77.9%
AUS in January82.8%
AUS in February81.9%
AUS in March73.3%
AUS in April77.5%
AUS in May75.1%
AUS in June69.1%

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