Flight number record
UA 1789
United Airlines · Washington to San Antonio
- Route
- IAD → SAT
- Departs
- 08:15
- Flights
- 264
- Period
- September 2025 to August 2026
Historical statistics for September 2025 to August 2026, not live status. For today’s UA 1789, check with United Airlines.
UA 1789 earns an A+. Nearly every flight arrives inside the 15-minute window the DOT uses to define an on-time arrival, which puts it 16 points better than the national rate of 77.3%. When something does go wrong the average delay runs roughly 45 minutes. That rests on 264 flights, with a median arrival 19 minutes early.
Set against the rest of the country, UA 1789's record is 16 points better than the US average of 77.3%. That gap is worth roughly 162 fewer late arrivals for every thousand flights.
Key figures
On time
93.5%
Arrivals under 15 minutes late, of 262 completed flights
Avg delay
47 min
Across delayed arrivals only, not all flights
Cancelled
0.76%
National rate is 1.89%
1 hour+ late
1.1%
National rate is 8.3%
These figures cover 264 flights between September 2025 and August 2026. The median arrival is 19 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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Schedule
When UA 1789 flies
UA 1789 flies IAD to SAT without a single fixed slot. Its most common scheduled departure was 08:15, used on 128 of 264 flights, with 08:25 (97 flights) next.
- Departs 08:15128 flights48.5%
- Departs 08:2597 flights36.7%
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 08:15 departure sits in the 8am–11am window. Across every US flight scheduled in that window the on-time rate is 83.9%, and UA 1789 runs 10 points better at 93.5%. Early departures usually start with an aircraft that has not flown yet that day, which is most of why the window does well.
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Against the route
UA 1789 next to IAD to SAT
Every carrier on IAD to SAT combined arrived on time 84.7% of the time across 644 flights, so UA 1789 is 9 points ahead of it. Across its whole network United Airlines managed 78.8%, which this flight beats by 15 points.
| Compared with | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| UA 1789thin sample | 264 | 93.5% | 47 min | 0.76% | A+ |
| All United Airlines on IAD–SAT | 644 | 84.7% | 108 min | 0.62% | B+ |
| All carriers on IAD–SAT | 644 | 84.7% | 108 min | 0.62% | B+ |
| United Airlines, whole network | 830,825 | 78.8% | 73 min | 1.02% | B |
Across the year
UA 1789 quarter by quarter
Quarter by quarter UA 1789 held fairly steady: 92.6% in Oct–Dec 2025, 91.7% in Jan–Mar 2026, 96.9% in Apr–Jun 2026 and 91.4% in Jul–Sep 2026. A spread of 6 points is about what a sample of this size moves on its own, so the annual figure is a fair summary.
- Jul–Sep 202521 flights—
- Oct–Dec 202581 flights92.6%
- Jan–Mar 202661 flights91.7%
- Apr–Jun 202666 flights96.9%
- Jul–Sep 202635 flights91.4%
Scale runs 85% to 100%. Rows with fewer than 30 flights show a dash.
By weekday, UA 1789 ranged from 90.7% on Sunday to 96.9% on Tuesday. With about 38 flights behind each day, a spread of 6 points is inside normal variation, so the day you fly is not worth changing for this flight.
Arrival by arrival
How late UA 1789 runs when it is late
UA 1789 often beats the schedule: 158 of 262 completed flights, 60%, arrived 15 minutes or more early. The 17 late arrivals split 5 under half an hour, 9 between 30 and 60 minutes, and 3 an hour or more.
- 15+ min early158 flights60.3%
- Within 15 min87 flights33.2%
- 15–29 min late5 flights1.9%
- 30–59 min late9 flights3.4%
- 1–2 hours late2 flights0.8%
- 2+ hours late1 flights0.4%
Scale runs 0% to 100%.
Share of 262 completed flights by arrival against schedule.
Only 13 of 262 completed flights left 15 minutes late or more, too few to say how often the time is made up.
The worst days
Worst days for UA 1789
The latest arrival of the period was on 6 September 2025, 3 hours 36 minutes behind schedule; most of its delay minutes were filed as a late-arriving aircraft. The five worst days are spread across September, November, January and December, with no single month standing out.
| Date | Arrived late by | Largest filed cause |
|---|---|---|
| 6 September 2025 | 3 hours 36 minutes | Late-arriving aircraft |
| 30 November 2025 | 1 hour 27 minutes | Carrier |
| 26 January 2026 | 1 hour 5 minutes | National Airspace System |
| 30 January 2026 | 53 minutes | Carrier |
| 12 December 2025 | 41 minutes | National Airspace System |
Delay causes
Why UA 1789 runs late
Carrier accounts for 43% of the 797 delay minutes carriers reported here, and the remaining four split what is left.
- 43%Carrier
- 32%Late-arriving aircraft
- 25%National Airspace System
The largest share of delay minutes, 43%, falls under carrier control: crew scheduling, maintenance, fuelling, baggage. It accounts for 342 of the 797 delay minutes reported here. The split is drawn from 797 delay minutes reported on UA 1789.
Cancellations are rare at 0.76%, 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
Badly late arrivals are rare here: only 1.1% land an hour or more behind schedule, against 8.3% 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.
The 1,362 miles between these two airports put this in the middle of the US network, around two and a half to three hours of block time. That is enough cruise to absorb a ten-minute late pushback and not enough to absorb thirty.
The same number turns up on three other city pairs in the data, including RDU to IAD (198), SAT to DEN (111) and IAD to ORF (21), but none flew often enough under UA 1789 to report a rate for. Carriers move flight numbers between routes, so the figures on this page apply to IAD to SAT only.
One caution: this is a thin sample. 264 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 1789
For a booking, UA 1789 has one of the better records a US domestic flight can show: 93.5% on time and 0.76% cancelled. That is a base rate, not a promise about any single day.
Related
Where to go next
- Washington Dulles International (IAD) delay statistics
- San Antonio International (SAT) 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 to read this site: grades, sample sizes, and honest caveats
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.