Carrier route record
UALAX→IAD
United Airlines · Los Angeles to Washington
- Flights
- 2,341
- Period
- September 2025 to August 2026
- Share of route
- 95%
- Carriers
- 2
Historical statistics for September 2025 to August 2026, not live status. For today’s flights, check with United Airlines.
United on LAX to IAD earns an A+. Close to nine flights in ten arrive inside the 15-minute window the DOT uses to define an on-time arrival, which puts it 11 points better than the national rate of 77.3%. When something does go wrong the average delay runs roughly 55 minutes. That rests on 2,341 flights, with a median arrival 11 minutes early.
Set against the rest of the country, United's LAX to IAD record is 11 points better than the US average of 77.3%. That gap is worth roughly 107 fewer late arrivals for every thousand flights.
Key figures
On time
88.0%
Arrivals under 15 minutes late, of 2,320 completed flights
Avg delay
54 min
Across delayed arrivals only, not all flights
Cancelled
0.56%
National rate is 1.89%
Whole route
87.5%
Every carrier on LAX to IAD, 2,461 flights
These figures cover 2,341 flights between September 2025 and August 2026. The median arrival is 11 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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Carrier by carrier
United against every carrier on LAX to IAD
United flew 2,341 of the 2,461 flights on LAX to IAD, most of the route. Its 88.0% on time is about level with the route as a whole at 87.5%. Ranked by on-time rate it is first of two carriers on the route, where the range runs from United at 88.0% to American at 76.5%. One of those carriers flew fewer than 365 flights here, so treat their positions as rough.
Only one carrier clears this site's 365-flight floor here, so there is no comparison to draw. The table below is the full picture.
| Airline | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| United Airlines (this page) | 2,341 | 88.0% | 54 min | 0.56% | A+ |
| American Airlinesthin sample | 120 | 76.5% | 71 min | 0.00% | B+ |
Flight by flight
United flight numbers on LAX to IAD
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.
Departure window
When United runs best on this route
Departure time matters more here than the choice of carrier. The gap between the best and worst window is 11 points, against half a point between the best and worst carrier.
- 5am–8am74 flights95.9%
- 8am–11am685 flights85.1%
- 11am–2pm500 flights87.4%
- 2pm–5pm262 flights90.0%
- 5pm–8pm—
- 8pm–5am820 flights89.4%
Scale runs 75% to 100%. Rows with fewer than 30 flights show a dash.
Book the early departure. Flights leaving between 5am–8am arrive on time 95.9% of the time, against 85.1% for the morning window. That is 11 points of difference for no extra money, and it comes from the same aircraft having had no earlier flight to fall behind on. The 8pm–5am window is the busiest, with 820 flights scheduled in it.
Across the year
United on LAX to IAD through the year
April is the best month on the calendar at 96.0% on time. Shoulder season thins the schedule and takes the summer weather with it, and the operation gets its margin back. June was the busiest month here, with 223 flights.
Across the week, Tuesday is the strongest day at 91.9% on time and Saturday the weakest at 83.4%, a spread of 9 points.
Arrival by arrival
How late United on LAX to IAD runs when it is late
United on LAX to IAD often beats the schedule: 940 of 2,320 completed flights, 41%, arrived 15 minutes or more early. The 278 late arrivals split 118 under half an hour, 87 between 30 and 60 minutes, and 73 an hour or more.
- 15+ min early940 flights40.5%
- Within 15 min1,102 flights47.5%
- 15–29 min late118 flights5.1%
- 30–59 min late87 flights3.8%
- 1–2 hours late43 flights1.9%
- 2+ hours late30 flights1.3%
Scale runs 0% to 100%.
Share of 2,320 completed flights by arrival against schedule.
A late pushback is often recovered here: of 307 departures that left 15 minutes late or more, 95 still arrived on time. 66 flights left on time and still arrived late.
The worst days
Worst days for United on LAX to IAD
The latest arrival of the period was on 7 January 2026, 6 hours 31 minutes behind schedule; most of its delay minutes were filed as a late-arriving aircraft. The same cause led on four of the five worst days.
| Date | Arrived late by | Largest filed cause |
|---|---|---|
| 7 January 2026 | 6 hours 31 minutes | Late-arriving aircraft |
| 21 August 2026 | 4 hours 58 minutes | Late-arriving aircraft |
| 25 September 2025 | 4 hours 50 minutes | Late-arriving aircraft |
| 20 August 2026 | 4 hours 14 minutes | Carrier |
| 29 July 2026 | 4 hours 1 minute | Late-arriving aircraft |
Delay causes
Why United runs late on this route
Carriers report a reason for every delay minute they cause, in five DOT categories. The split below is by minutes, not by number of flights, so a handful of very long weather delays weighs as much as many short ones. It covers 15,000 reported delay minutes.
- 42%Carrier
- 39%Late-arriving aircraft
- 19%National Airspace System
39% of delay minutes trace back to a late-arriving aircraft, meaning the plane was already behind before it got here. Across 15,000 reported delay minutes here, that single category outweighs weather by 39 to one. The split is drawn from 14,970 reported delay minutes.
The largest share of delay minutes, 42%, falls under carrier control: crew scheduling, maintenance, fuelling, baggage. It accounts for 6,266 of the 15,000 delay minutes reported here.
Cancellations are rare at 0.56%, 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 stage length
What a delay here costs
Badly late arrivals are rare here: only 3.1% 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.
At 2,288 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 return leg is a different operation and performs like one: it runs 84.6% on time across 2,340 flights, 3 points below this direction. Departure banks, aircraft rotations and the congestion at each end all differ, so scoring the two directions together would average away a real 3 points of difference.
The sample behind these figures is 2,341 flights, enough that the headline rate is stable to within roughly a point. The hour-block and month splits divide that further, so read the thinner bars with more caution than the headline.
What to do with this
Booking United on LAX to IAD
Put together: the calendar is the biggest lever here, not the carrier or the hour. April runs 96.0% on time and March 75.8%, a swing of 20 points. If the dates move at all, move them out of March before you think about anything else. 2,320 completed flights over 12 months sit behind that.
Related
Where to go next
- LAX to IAD, every carrier
- United on IAD to LAX, the return leg
- American Airlines on LAX to IAD76.5%
- United Airlines network-wide record
- Los Angeles International (LAX) delay statistics
- Washington Dulles International (IAD) delay statistics
- Why the first flight of the morning is statistically safest
- The best time of day to fly, according to 7.05 million flight records
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.