Flight number record
UA 1323
United Airlines · Washington to Las Vegas
- Route
- IAD → LAS
- Departs
- 09:00
- Flights
- 317
- Period
- July 2025 to June 2026
Historical statistics for July 2025 to June 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 16 points better than the national rate of 77.6%. When something does go wrong the average delay runs about an hour. That rests on 317 flights, with a median arrival 16 minutes early.
Set against the rest of the country, UA 1323's record is 16 points better than the US average of 77.6%. That gap is worth roughly 163 fewer late arrivals for every thousand flights.
Key figures
On time
93.9%
Arrivals under 15 minutes late, of 314 completed flights
Avg delay
62 min
Across delayed arrivals only, not all flights
Cancelled
0.95%
National rate is 1.81%
1 hour+ late
1.6%
National rate is 8.1%
These figures cover 317 flights between July 2025 and June 2026. The median arrival is 16 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.
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 193 of 317 flights, with 08:45 (70 flights) and 08:30 (36 flights) next. Carriers retime flights through the season, so the rates here blend slightly different positions in the aircraft's day.
- Departs 09:00193 flights60.9%
- Departs 08:4570 flights22.1%
- Departs 08:3036 flights11.4%
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 09:00 departure sits in the 8am–11am window. Across every US flight scheduled in that window the on-time rate is 84.1%, and UA 1323 runs 10 points better at 93.9%. 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 1323 next to IAD to LAS
Every carrier on IAD to LAS combined arrived on time 85.1% of the time across 1,108 flights, so UA 1323 is 9 points ahead of it. United flew 1,009 flights on the same city pair under all its flight numbers, including this one, and those ran 86.8% on time. Across its whole network United Airlines managed 79.0%, which this flight beats by 15 points.
| Compared with | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| UA 1323thin sample | 317 | 93.9% | 62 min | 0.95% | A+ |
| All United Airlines on IAD–LAS | 1,009 | 86.8% | 70 min | 0.50% | A+ |
| All carriers on IAD–LAS | 1,108 | 85.1% | 69 min | 0.45% | A+ |
| United Airlines, whole network | 821,041 | 79.0% | 72 min | 1.01% | B |
Across the year
UA 1323 quarter by quarter
Quarter by quarter UA 1323 held fairly steady: 90.2% 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 10 points is about what a sample of this size moves on its own, so the annual figure is a fair summary.
- Jul–Sep 202592 flights90.2%
- Oct–Dec 202592 flights93.5%
- Jan–Mar 202683 flights95.0%
- Apr–Jun 202650 flights100.0%
Scale runs 80% to 100%. Rows with fewer than 30 flights show a dash.
By weekday, UA 1323 ranged from 90.9% on Tuesday to 97.8% on Friday. With about 45 flights behind each day, a spread of 7 points is inside normal variation, so the day you fly is not worth changing for this flight.
Delay causes
Why UA 1323 runs late
One category carries most of the weight here. Carrier accounts for 47% of the 1,168 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.
- 47%Carrier
- 38%Late-arriving aircraft
- 12%National Airspace System
- 2%Extreme weather
38% of delay minutes trace back to a late-arriving aircraft, meaning the plane was already behind before it got here. That is a cascade, and cascades start small and grow through the day. Across 1,168 reported delay minutes here, that single category outweighs weather by 17 to one. It is the strongest argument for booking the first departure of the morning, when the aircraft has been sitting at the gate overnight with nothing to inherit. The split is drawn from 1,168 delay minutes reported on UA 1323.
Cancellations sit at 0.95% against a national 1.81%, 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 1.6% land an hour or more behind schedule, against 8.1% 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 (118) 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. 317 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: 93.9% on time and 0.95% 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
- 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
- Why the first flight of the morning is statistically safest
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.