Carrier route record
UASFO→AUS
United Airlines · San Francisco to Austin
- Flights
- 1,637
- Period
- September 2025 to August 2026
- Share of route
- 59%
- Carriers
- 5
Historical statistics for September 2025 to August 2026, not live status. For today’s flights, check with United Airlines.
United on SFO to AUS lands a B+, 2 points better than the national rate of 77.3%. About one flight in five arrives 15 minutes late or worse, and those flights are late by roughly 55 minutes on average. That rests on 1,637 flights. The strongest carrier on the route with a full sample, Delta Air Lines, flew 500 at 64.8% on time.
The US average over the same twelve months is 77.3%, so there is little to separate United on SFO to AUS from the country as a whole. The variation that matters here is internal: which carrier, and what time of day.
Key figures
On time
79.6%
Arrivals under 15 minutes late, of 1,624 completed flights
Avg delay
53 min
Across delayed arrivals only, not all flights
Cancelled
0.37%
National rate is 1.89%
Whole route
71.8%
Every carrier on SFO to AUS, 2,786 flights
These figures cover 1,637 flights between September 2025 and August 2026. The median arrival is 3 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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Carrier by carrier
United against every carrier on SFO to AUS
United flew 1,637 of the 2,786 flights on SFO to AUS, most of the route. Its 79.6% on time is 8 points better than the route as a whole, which runs 71.8%. Ranked by on-time rate it is number three of five carriers on the route, where the range runs from Alaska at 87.5% to Southwest at 40.1%. Two of those carriers flew fewer than 365 flights here, so treat their positions as rough.
The choice of carrier is not cosmetic here. Delta Air Lines arrives on time 64.8% of the time; Southwest Airlines manages 40.1%. Sample sizes sit next to every figure, because a two-point gap across 411 flights means less than a ten-point one.
| Airline | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| Alaska Airlinesthin sample | 225 | 87.5% | 69 min | 0.44% | A+ |
| SkyWest Airlinesthin sample | 13 | 84.6% | 43 min | 0.00% | B+ |
| United Airlines (this page) | 1,637 | 79.6% | 53 min | 0.37% | B+ |
| Delta Air Lines | 500 | 64.8% | 86 min | 1.20% | D |
| Southwest Airlines | 411 | 40.1% | 64 min | 0.00% | F+ |
The spread between Delta and Southwest is 25 points, wide enough that it should decide the booking. On a hundred trips that is 25 more arrivals inside the on-time window.
Flight by flight
United flight numbers on SFO to AUS
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Departure window
When United runs best on this route
Departure time matters more here than the choice of carrier. The gap between the best and worst window is 31 points, against 25 points between the best and worst carrier.
- 5am–8am197 flights97.4%
- 8am–11am174 flights78.2%
- 11am–2pm556 flights77.3%
- 2pm–5pm150 flights66.7%
- 5pm–8pm408 flights78.5%
- 8pm–5am152 flights82.2%
Scale runs 60% to 100%.
Book the early departure. Flights leaving between 5am–8am arrive on time 97.4% of the time, against 66.7% for the afternoon window. That is 31 points of difference for no extra money, and it comes from the same aircraft having had no earlier flight to fall behind on. The 11am–2pm window is the busiest, with 556 flights scheduled in it.
Across the year
United on SFO to AUS through the year
August is the worst month at 57.0% on time, 34 points below September, the best at 90.8%. Summer afternoon convection and peak-season schedules land on the same weeks every year, so this is a pattern you can book around rather than a run of bad luck. May was the busiest month here, with 159 flights.
Across the week, Wednesday is the strongest day at 84.6% on time and Friday the weakest at 74.3%, a spread of 10 points.
Arrival by arrival
How late United on SFO to AUS runs when it is late
The 331 late arrivals split 141 under half an hour, 99 between 30 and 60 minutes, and 91 an hour or more.
- 15+ min early341 flights21.0%
- Within 15 min952 flights58.6%
- 15–29 min late141 flights8.7%
- 30–59 min late99 flights6.1%
- 1–2 hours late62 flights3.8%
- 2+ hours late29 flights1.8%
Scale runs 0% to 100%.
Share of 1,624 completed flights by arrival against schedule.
75 of 327 late departures made up the time and arrived on time, 23% of them. 79 flights left on time and still arrived late.
The worst days
Worst days for United on SFO to AUS
The latest arrival of the period was on 25 December 2025, 6 hours 48 minutes behind schedule; most of its delay minutes were filed as a late-arriving aircraft. The same cause led on three of the five worst days.
| Date | Arrived late by | Largest filed cause |
|---|---|---|
| 25 December 2025 | 6 hours 48 minutes | Late-arriving aircraft |
| 24 August 2026 | 4 hours 51 minutes | Carrier |
| 6 July 2026 | 4 hours 33 minutes | Late-arriving aircraft |
| 28 May 2026 | 4 hours 15 minutes | Late-arriving aircraft |
| 19 January 2026 | 3 hours 51 minutes | Carrier |
Delay causes
Why United runs late on this route
Late-arriving aircraft accounts for 53% of the 18,000 delay minutes carriers reported here, and the remaining four split what is left.
- 53%Late-arriving aircraft
- 26%Carrier
- 21%National Airspace System
53% of delay minutes trace back to a late-arriving aircraft, meaning the plane was already behind before it got here. Across 18,000 reported delay minutes here, that single category outweighs weather by 53 to one. The split is drawn from 17,676 reported delay minutes.
The practical consequence: the 5am–8am departure is the one that starts clean. Its aircraft has no earlier leg to be late from, which is exactly why that window shows 97.4% on time here.
Cancellations are rare at 0.37%, 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 stage length
What a delay here costs
5.6% 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 roughly 55 minutes, which a normal layover absorbs.
At 1,504 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.
The return leg is a different operation and performs like one: it runs 75.5% on time across 1,638 flights, 4 points below this direction. Departure banks, aircraft rotations and the congestion at each end all differ, so scoring the two directions together would average away a real 4 points of difference.
The sample behind these figures is 1,637 flights, enough that the headline rate is stable to within roughly a point. The hour-block and month splits divide that further, so read the thinner bars with more caution than the headline.
What to do with this
Booking United on SFO to AUS
Put together: the calendar is the biggest lever here, not the carrier or the hour. September runs 90.8% on time and August 57.0%, a swing of 34 points. If the dates move at all, move them out of August before you think about anything else. 1,624 completed flights over 12 months sit behind that.
Related
Where to go next
- SFO to AUS, every carrier
- United on AUS to SFO, the return leg
- Alaska Airlines on SFO to AUS87.5%
- Delta Air Lines on SFO to AUS64.8%
- Southwest Airlines on SFO to AUS40.1%
- United Airlines network-wide record
- San Francisco International (SFO) delay statistics
- Austin-Bergstrom International (AUS) delay statistics
- Why the first flight of the morning is statistically safest
- Same route, different airline: where the carrier you pick matters most
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.