Flight number record

UA 1668

United Airlines · Austin to San Francisco

Route: AUS → SFO
Departs: 08:45
Flights: 312
Period: July 2025 to June 2026

Historical statistics for July 2025 to June 2026, not live status. For today’s UA 1668, check with United Airlines.

UA 1668 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 77.6%. The late ones land a little over an hour behind schedule. That rests on 312 flights, with a median arrival 7 minutes early.

On time

75.2%

Arrivals under 15 minutes late, of 310 completed flights

Avg delay

69 min

Across delayed arrivals only, not all flights

Cancelled

0.32%

National rate is 1.81%

1 hour+ late

10.6%

National rate is 8.1%

These figures cover 312 flights between July 2025 and June 2026. Beyond the headline rate, 10.6% of arrivals land a full hour or more behind schedule. That is the number that wrecks a connection, and it is not visible in an on-time percentage alone.

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 312 flights, with 09:55 (37 flights) and 10:15 (37 flights) next. Carriers retime flights through the season, so the rates here blend slightly different positions in the aircraft's day.

Departs 08:4565 flights20.8%
Departs 09:5537 flights11.9%
Departs 10:1537 flights11.9%

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 08:45 departure sits in the 8am–11am window. Across every US flight scheduled in that window the on-time rate is 84.1%, and UA 1668 runs 9 points worse at 75.2%. 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

UA 1668 next to AUS to SFO

Every carrier on AUS to SFO combined arrived on time 74.9% of the time across 2,795 flights, so UA 1668 is about level with it. United flew 1,655 flights on the same city pair under all its flight numbers, including this one, and those ran 78.8% on time. Across its whole network United Airlines managed 79.0%, which this flight trails by 4 points.

UA 1668 against its route and carrier
Compared with	Flights	On time	Avg delay	Cancelled	Grade
UA 1668thin sample	312	75.2%	69 min	0.32%	B+
All United Airlines on AUS–SFO	1,655	78.8%	74 min	0.79%	B+
All carriers on AUS–SFO	2,795	74.9%	65 min	0.86%	C+
United Airlines, whole network	821,041	79.0%	72 min	1.01%	B

Across the year

UA 1668 quarter by quarter

UA 1668 did not run the same all year. Its best quarter was Jul–Sep 2025 at 92.9% on time and its weakest Apr–Jun 2026 at 48.4%, a swing of 45 points on roughly 78 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 202542 flights92.9%
Oct–Dec 202589 flights85.4%
Jan–Mar 202690 flights84.1%
Apr–Jun 202691 flights48.4%

Scale runs 40% to 100%. Rows with fewer than 30 flights show a dash.

By weekday, UA 1668 did best on Saturday at 84.4% on time and worst on Thursday at 62.2%. Each day rests on about 45 flights, so a gap of 22 points is worth noticing but could still narrow in another year.

Delay causes

Why UA 1668 runs late

One category carries most of the weight here. National Airspace System accounts for 69% of the 5,285 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.

National Airspace System
69%
Carrier
16%
Late-arriving aircraft
14%

69% 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 3,667 minutes out of 5,285, against a national NAS share of 21%. The split is drawn from 5,285 delay minutes reported on UA 1668.

Cancellations are rare at 0.32%, 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

For anyone connecting, the number to weigh is not the on-time rate but the tail behind it. 10.6% of arrivals land a full hour or more behind schedule, against 8.1% nationally. A 45-minute layover does not survive that, and no amount of walking quickly changes it. Ninety minutes is the honest minimum 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 four other city pairs in the data, including SFO to PDX (181), SFO to SAN (56) and SEA to IAH (35), 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. 312 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 75.2% on time with 0.32% cancelled over 312 flights. Those are rates from the past twelve months, not a forecast for any particular day.

Where to go next

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

Key figures