Flight number record
UA 1323
United Airlines · Washington to Las Vegas
- Route
- IAD → LAS
- Departs
- 09:00
- Flights
- 277
- Period
- September 2025 to August 2026
Historical statistics for September 2025 to August 2026, not live status. For today’s UA 1323, check with United Airlines.
UA 1323 earns an A. Nearly every flight arrives inside the 15-minute window the DOT uses to define an on-time arrival, which puts it 18 points better than the national rate of 77.3%. When something does go wrong the average delay runs a little over an hour. That rests on 277 flights, with a median arrival 17 minutes early.
Set against the rest of the country, UA 1323's record is 18 points better than the US average of 77.3%. That gap is worth roughly 183 fewer late arrivals for every thousand flights.
Key figures
On time
95.6%
Arrivals under 15 minutes late, of 274 completed flights
Avg delay
73 min
Across delayed arrivals only, not all flights
Cancelled
1.08%
National rate is 1.89%
1 hour+ late
1.5%
National rate is 8.3%
These figures cover 277 flights between September 2025 and August 2026. The median arrival is 17 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 1323 flies
UA 1323 flies IAD to LAS without a single fixed slot. Its most common scheduled departure was 09:00, used on 153 of 277 flights, with 08:45 (70 flights) and 08:30 (36 flights) next.
- Departs 09:00153 flights55.2%
- Departs 08:4570 flights25.3%
- Departs 08:3036 flights13.0%
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 09:00 departure sits in the 8am–11am window. Across every US flight scheduled in that window the on-time rate is 83.9%, and UA 1323 runs 12 points better at 95.6%. 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 1323 next to IAD to LAS
Every carrier on IAD to LAS combined arrived on time 85.3% of the time across 1,069 flights, so UA 1323 is 10 points ahead of it. United flew 965 flights on the same city pair under all its flight numbers, including this one, and those ran 88.0% on time. Across its whole network United Airlines managed 78.8%, which this flight beats by 17 points.
| Compared with | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| UA 1323thin sample | 277 | 95.6% | 73 min | 1.08% | A |
| All United Airlines on IAD–LAS | 965 | 88.0% | 80 min | 0.52% | A+ |
| All carriers on IAD–LAS | 1,069 | 85.3% | 71 min | 0.56% | A+ |
| United Airlines, whole network | 830,825 | 78.8% | 73 min | 1.02% | B |
Across the year
UA 1323 quarter by quarter
Quarter by quarter UA 1323 held fairly steady: 96.7% in Jul–Sep 2025, 93.5% in Oct–Dec 2025, 95.0% in Jan–Mar 2026 and 100.0% in Apr–Jun 2026. A spread of 7 points is about what a sample of this size moves on its own, so the annual figure is a fair summary.
- Jul–Sep 202530 flights96.7%
- Oct–Dec 202592 flights93.5%
- Jan–Mar 202683 flights95.0%
- Apr–Jun 202650 flights100.0%
- Jul–Sep 202622 flights—
Scale runs 85% to 100%. Rows with fewer than 30 flights show a dash.
By weekday, UA 1323 ranged from 92.1% on Tuesday to 100.0% on Wednesday. With about 40 flights behind each day, a spread of 8 points is inside normal variation, so the day you fly is not worth changing for this flight.
Arrival by arrival
How late UA 1323 runs when it is late
UA 1323 often beats the schedule: 162 of 274 completed flights, 59%, arrived 15 minutes or more early. The 12 late arrivals split 4 under half an hour, 4 between 30 and 60 minutes, and 4 an hour or more.
- 15+ min early162 flights59.1%
- Within 15 min100 flights36.5%
- 15–29 min late4 flights1.5%
- 30–59 min late4 flights1.5%
- 1–2 hours late1 flights0.4%
- 2+ hours late3 flights1.1%
Scale runs 0% to 100%.
Share of 274 completed flights by arrival against schedule.
Only 19 of 274 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 1323
The latest arrival of the period was on 3 November 2025, 3 hours 29 minutes behind schedule; most of its delay minutes were filed as a late-arriving aircraft. On three of the five worst days the largest share was filed as carrier-caused (crew, maintenance, fuelling, baggage).
| Date | Arrived late by | Largest filed cause |
|---|---|---|
| 3 November 2025 | 3 hours 29 minutes | Late-arriving aircraft |
| 8 December 2025 | 2 hours 37 minutes | Carrier |
| 19 January 2026 | 2 hours 1 minute | Carrier |
| 16 December 2025 | 1 hour 48 minutes | Carrier |
| 16 August 2026 | 59 minutes | National Airspace System |
Delay causes
Why UA 1323 runs late
Carrier accounts for 56% of the 879 delay minutes carriers reported here, and the remaining four split what is left.
- 56%Carrier
- 21%Late-arriving aircraft
- 21%National Airspace System
- 3%Extreme weather
The largest share of delay minutes, 56%, falls under carrier control: crew scheduling, maintenance, fuelling, baggage. It accounts for 488 of the 879 delay minutes reported here. The split is drawn from 879 delay minutes reported on UA 1323.
Cancellations sit at 1.08% against a national 1.89%, which is ordinary. Diversions add another 0.00%.
Connections and routes
What a delay on this flight costs
Badly late arrivals are rare here: only 1.5% 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.
At 2,065 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 LAS to DEN (180) and DEN to GTF (24), but none flew often enough under UA 1323 to report a rate for. Carriers move flight numbers between routes, so the figures on this page apply to IAD to LAS only.
One caution: this is a thin sample. 277 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 1323
For a booking, UA 1323 has one of the better records a US domestic flight can show: 95.6% on time and 1.08% cancelled. That is a base rate, not a promise about any single day.
Related
Where to go next
- IAD to LAS, every carrier and departure
- LAS to IAD, the return direction
- United Airlines 2156 on the same route89.3%
- Washington Dulles International (IAD) delay statistics
- Harry Reid International (LAS) 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
- Worst months to fly in the US, ranked by the data
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.