Flight number record
UA 1668
United Airlines · Austin to San Francisco
- Route
- AUS → SFO
- Departs
- 08:45
- Flights
- 361
- Period
- September 2025 to August 2026
Historical statistics for September 2025 to August 2026, not live status. For today’s UA 1668, check with United Airlines.
UA 1668 sits in the middle of the pack with a C+. About seven flights in ten arrive on time by the DOT's definition, 6 points worse than the national rate of 77.3%. The late ones land about an hour behind schedule. That rests on 361 flights, with a median arrival 4 minutes early.
The national on-time rate over the same period is 77.3%, so UA 1668 runs 6 points behind the country as a whole. Across a thousand flights that is about 63 extra late arrivals.
Key figures
On time
71.0%
Arrivals under 15 minutes late, of 359 completed flights
Avg delay
64 min
Across delayed arrivals only, not all flights
Cancelled
0.28%
National rate is 1.89%
1 hour+ late
11.4%
National rate is 8.3%
These figures cover 361 flights between September 2025 and August 2026. Beyond the headline rate, 11.4% 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.
Schedule
When UA 1668 flies
UA 1668 flies AUS to SFO without a single fixed slot. Its most common scheduled departure was 08:45, used on 65 of 361 flights, with 08:40 (41 flights) and 09:55 (37 flights) next.
- Departs 08:4565 flights18.0%
- Departs 08:4041 flights11.4%
- Departs 09:5537 flights10.2%
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 08:45 departure sits in the 8am–11am window. Across every US flight scheduled in that window the on-time rate is 83.9%, and UA 1668 runs 13 points worse at 71.0%. Early departures usually start with an aircraft that has not flown yet that day, which is most of why the window does well.
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.
Against the route
UA 1668 next to AUS to SFO
Every carrier on AUS to SFO combined arrived on time 72.4% of the time across 2,788 flights, so UA 1668 is about level with it. United flew 1,638 flights on the same city pair under all its flight numbers, including this one, and those ran 75.5% on time. Across its whole network United Airlines managed 78.8%, which this flight trails by 8 points.
| Compared with | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| UA 1668thin sample | 361 | 71.0% | 64 min | 0.28% | C+ |
| All United Airlines on AUS–SFO | 1,638 | 75.5% | 76 min | 0.37% | B+ |
| All carriers on AUS–SFO | 2,788 | 72.4% | 67 min | 0.54% | C+ |
| United Airlines, whole network | 830,825 | 78.8% | 73 min | 1.02% | B |
Across the year
UA 1668 quarter by quarter
UA 1668 did not run the same all year. Its best quarter was Oct–Dec 2025 at 85.4% on time and its weakest Apr–Jun 2026 at 48.4%, a swing of 37 points on roughly 90 flights a quarter. The twelve-month rate averages over that, so if you are flying in a weak quarter the quarter's own figure is the better guide.
- Jul–Sep 202529 flights—
- Oct–Dec 202589 flights85.4%
- Jan–Mar 202690 flights84.1%
- Apr–Jun 202691 flights48.4%
- Jul–Sep 202662 flights56.5%
Scale runs 40% to 90%. Rows with fewer than 30 flights show a dash.
By weekday, UA 1668 did best on Saturday at 80.8% on time and worst on Thursday at 57.7%. Each day rests on about 52 flights, so a gap of 23 points is worth noticing but could still narrow in another year.
Arrival by arrival
How late UA 1668 runs when it is late
UA 1668 often beats the schedule: 106 of 359 completed flights, 30%, arrived 15 minutes or more early. The 104 late arrivals split 27 under half an hour, 36 between 30 and 60 minutes, and 41 an hour or more.
- 15+ min early106 flights29.5%
- Within 15 min149 flights41.5%
- 15–29 min late27 flights7.5%
- 30–59 min late36 flights10.0%
- 1–2 hours late31 flights8.6%
- 2+ hours late10 flights2.8%
Scale runs 0% to 100%.
Share of 359 completed flights by arrival against schedule.
Time lost at the gate mostly stays lost. Of 95 departures that left 15 minutes late or more, only 11 made it up before arrival. In the other direction, 20 flights left on time yet arrived 15 minutes late or more, so that delay built up after pushback: in the air, in a holding pattern or on the ground at SFO.
The worst days
Worst days for UA 1668
The latest arrival of the period was on 5 January 2026, 4 hours 52 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 |
|---|---|---|
| 5 January 2026 | 4 hours 52 minutes | Late-arriving aircraft |
| 28 October 2025 | 4 hours 11 minutes | Late-arriving aircraft |
| 7 August 2026 | 3 hours 19 minutes | Late-arriving aircraft |
| 11 March 2026 | 3 hours 10 minutes | Carrier |
| 13 November 2025 | 2 hours 57 minutes | National Airspace System |
Delay causes
Why UA 1668 runs late
National Airspace System accounts for 71% of the 6,613 delay minutes carriers reported here, and the remaining four split what is left.
- 71%National Airspace System
- 15%Carrier
- 14%Late-arriving aircraft
71% 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 4,698 minutes out of 6,613, against a national NAS share of 21%. The split is drawn from 6,613 delay minutes reported on UA 1668.
Cancellations are rare at 0.28%, 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
11.4% 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 same number turns up on two other city pairs in the data, including SFO to PDX (170) and SFO to SAN (77), but none flew often enough under UA 1668 to report a rate for. Carriers move flight numbers between routes, so the figures on this page apply to AUS to SFO only.
One caution: this is a thin sample. 361 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 UA 1668
For a booking, read UA 1668 as 71.0% on time with 0.28% cancelled over 361 flights. Those are rates from the past twelve months, not a forecast for any particular day.
Related
Where to go next
- AUS to SFO, every carrier and departure
- SFO to AUS, the return direction
- Delta Air Lines 381 on the same route74.7%
- United Airlines 292 on the same route61.0%
- United Airlines 2177 on the same route92.5%
- Austin-Bergstrom International (AUS) delay statistics
- San Francisco International (SFO) delay statistics
- United Airlines on-time record
- Every United Airlines flight number with a record
- The most and least reliable flight numbers in the US
- How often a connection fails at the major US hubs
A flight number here means United 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.