Carrier route record
UAAUS→SFO
United Airlines · Austin to San Francisco
- Flights
- 1,638
- 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 AUS to SFO 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 a little over an hour behind schedule. That rests on 1,638 flights. The strongest carrier on the route with a full sample, Delta Air Lines, flew 500 at 69.2% on time.
The US average over the same twelve months is 77.3%, so there is little to separate United on AUS to SFO from the country as a whole. The variation that matters here is internal: which carrier, and what time of day.
Key figures
On time
75.5%
Arrivals under 15 minutes late, of 1,630 completed flights
Avg delay
76 min
Across delayed arrivals only, not all flights
Cancelled
0.37%
National rate is 1.89%
Whole route
72.4%
Every carrier on AUS to SFO, 2,788 flights
These figures cover 1,638 flights between September 2025 and August 2026. Beyond the headline rate, 10.5% of arrivals land a full hour or more behind schedule, against 8.3% nationally.
Fare search by Aviasales, a Travelpayouts partner. Booking through it may earn this site a commission at no cost to you; it changes no figure here.
Carrier by carrier
United against every carrier on AUS to SFO
United flew 1,638 of the 2,788 flights on AUS to SFO, most of the route. Its 75.5% on time is 3 points better than the route as a whole, which runs 72.4%. Ranked by on-time rate it is number three of five carriers on the route, where the range runs from SkyWest at 84.6% to Southwest at 57.0%. 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 69.2% of the time; Southwest Airlines manages 57.0%. 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 |
|---|---|---|---|---|---|
| SkyWest Airlinesthin sample | 13 | 84.6% | 17 min | 0.00% | B+ |
| Alaska Airlinesthin sample | 226 | 84.4% | 55 min | 0.88% | B+ |
| United Airlines (this page) | 1,638 | 75.5% | 76 min | 0.37% | B+ |
| Delta Air Lines | 500 | 69.2% | 63 min | 1.00% | C |
| Southwest Airlines | 411 | 57.0% | 55 min | 0.49% | D+ |
The spread between Delta and Southwest is 12 points, wide enough that it should decide the booking. On a hundred trips that is 12 more arrivals inside the on-time window.
Flight by flight
United flight numbers on AUS to SFO
Timetable by Aviasales, a Travelpayouts partner. Booking through it may earn this site a commission at no cost to you; it changes no figure here.
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 61 points, against 12 points between the best and worst carrier.
- 5am–8am442 flights92.3%
- 8am–11am361 flights71.0%
- 11am–2pm224 flights70.0%
- 2pm–5pm259 flights78.3%
- 5pm–8pm253 flights71.7%
- 8pm–5am99 flights31.3%
Scale runs 25% to 100%.
The 8pm–5am window is where this operation falls apart: 31.3% on time, against 92.3% for the 5am–8am slot. By evening the aircraft flying these rotations have absorbed a full day of small delays and there is no slack left to recover in. The 5am–8am window is the busiest, with 442 flights scheduled in it.
Across the year
United on AUS to SFO through the year
September is the best month on the calendar at 93.3% on time. Shoulder season thins the schedule and takes the summer weather with it, and the operation gets its margin back. May was the busiest month here, with 159 flights.
Across the week, Saturday is the strongest day at 85.6% on time and Monday the weakest at 69.5%, a spread of 16 points.
Arrival by arrival
How late United on AUS to SFO runs when it is late
United on AUS to SFO often beats the schedule: 528 of 1,630 completed flights, 32%, arrived 15 minutes or more early. The 400 late arrivals split 102 under half an hour, 127 between 30 and 60 minutes, and 171 an hour or more.
- 15+ min early528 flights32.4%
- Within 15 min702 flights43.1%
- 15–29 min late102 flights6.3%
- 30–59 min late127 flights7.8%
- 1–2 hours late110 flights6.7%
- 2+ hours late61 flights3.7%
Scale runs 0% to 100%.
Share of 1,630 completed flights by arrival against schedule.
68 of 416 late departures made up the time and arrived on time, 16% of them. 52 flights left on time and still arrived late.
The worst days
Worst days for United on AUS to SFO
The latest arrival of the period was on 5 April 2026, 11 hours 11 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 |
|---|---|---|
| 5 April 2026 | 11 hours 11 minutes | Carrier |
| 16 March 2026 | 9 hours 4 minutes | Late-arriving aircraft |
| 17 July 2026 | 8 hours 55 minutes | Carrier |
| 9 September 2025 | 8 hours 17 minutes | Carrier |
| 18 May 2026 | 7 hours 8 minutes | Late-arriving aircraft |
Delay causes
Why United runs late on this route
National Airspace System accounts for 52% of the 30,000 delay minutes carriers reported here, and the remaining four split what is left.
- 52%National Airspace System
- 30%Late-arriving aircraft
- 17%Carrier
- 1%Extreme weather
52% of delay minutes are charged to the National Airspace System: air traffic volume, runway configuration, ground stops. No carrier can price its way out of that, which is why airport choice moves the number here more than carrier choice does. That is 16,000 minutes out of 30,000, against a national NAS share of 21%. The split is drawn from 30,445 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 92.3% 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
10.5% of arrivals land a full hour or more behind schedule, against 8.3% nationally. Ninety minutes is the honest minimum for a connection here, and two hours if the onward flight is on a separate ticket.
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 79.6% on time across 1,637 flights, 4 points above 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 1,638 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 AUS to SFO
Put together: the calendar is the biggest lever here, not the carrier or the hour. September runs 93.3% on time and May 51.6%, a swing of 42 points. If the dates move at all, move them out of May before you think about anything else. 1,630 completed flights over 12 months sit behind that.
Related
Where to go next
- AUS to SFO, every carrier
- United on SFO to AUS, the return leg
- Alaska Airlines on AUS to SFO84.4%
- Delta Air Lines on AUS to SFO69.2%
- Southwest Airlines on AUS to SFO57.0%
- United Airlines network-wide record
- Austin-Bergstrom International (AUS) delay statistics
- San Francisco International (SFO) delay statistics
- Same route, different airline: where the carrier you pick matters most
- The best time of day to fly, according to 7.05 million flight records
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.