Route reliability record
LAX→IAD
Los Angeles to Washington
- Flights
- 2,461
- Period
- September 2025 to August 2026
- Distance
- 2,288 mi
- Carriers
- 2
This route 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 10 points better than the national rate of 77.3%. When something does go wrong the average delay runs about an hour. That rests on 2,461 LAX to IAD flights, with a median arrival 11 minutes early.
Best time to fly LAX to IAD: a 5am–8am departure, ideally on a Tuesday. Flights in that window arrived on time 95.9% of the time and Tuesday flights 90.5%, against 87.5% for the route overall.
Set against the rest of the country, this route's record is 10 points better than the US average of 77.3%. That gap is worth roughly 102 fewer late arrivals for every thousand flights.
Key figures
On time
87.5%
Arrivals under 15 minutes late, of 2,439 completed flights
Avg delay
56 min
Across delayed arrivals only, not all flights
Cancelled
0.53%
National rate is 1.89%
Best carrier
United
88.0% on time across 2,341 flights
These figures cover 2,461 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.
Fare search by Aviasales, a Travelpayouts partner. Booking through it may earn this site a commission at no cost to you; it changes no figure here.
Carrier by carrier
Which airline is most reliable on LAX to IAD
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 | 2,341 | 88.0% | 54 min | 0.56% | A+ |
| American Airlinesthin sample | 120 | 76.5% | 71 min | 0.00% | B+ |
Flight by flight
Flights on LAX to IAD
The flight numbers below flew this route at least 250 times in the period, busiest first. Each has its own record, with its schedule and delay causes.
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.
Best ways to make this trip
The most reliable ways to fly Los Angeles to Washington
Every airline on this route and on the routes between nearby airports, ranked by how often a scheduled flight actually operated and arrived on time. 3 of the top 4 use a different airport at one end.
| Option | Airline | Success | On time | Cancelled | Best departure | Most punctual flight |
|---|---|---|---|---|---|---|
| 1. LAX → BWILos Angeles to Baltimore | United Airlines | 88.8% | 89.1% | 0.35% | 11am–2pm, Mon | — |
| 2. LAX → IADLos Angeles to Washington | United Airlines | 87.5% | 88.0% | 0.56% | 5am–8am, Tue | UA 2667 10:39 |
| 3. LAX → DCALos Angeles to Washington | American Airlines | 79.6% | 80.5% | 1.10% | 5am–8am, Thu | — |
| 4. LAX → BWILos Angeles to Baltimore | Southwest Airlines | 75.4% | 76.2% | 1.08% | 5am–8am, Sat | — |
Success is the share of scheduled flights that operated and arrived less than 15 minutes late, so a cancelled flight counts against it. “(route)” means the best time comes from every carrier on the route rather than this airline alone.
Departure window
The best time of day to leave
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–11am686 flights85.1%
- 11am–2pm500 flights87.4%
- 2pm–5pm262 flights90.0%
- 5pm–8pm—
- 8pm–5am939 flights87.8%
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 939 flights scheduled in it.
Explore
Filter LAX to IAD by airline, time, month and day
Pick a breakdown and a carrier. The dashed mark on each row is the same slice for every US flight.
On LAX to IAD, the best departure window is 5am–8am at 95.9% on time and the worst is 8am–11am at 85.1%, a wide gap of 10.8 points. All US flights leaving 5am–8am ran 89.3%.
- 5–8am95.9%
- 8–11am85.1%
- 11am–2pm87.4%
- 2–5pm90.0%
- 5–8pm—
- 8pm–5am87.8%
best all US flightsScale 60% to 100%. Cells under 30 flights show a dash.
Across the year
When delays peak on this route
This route's year swings by 20 points from best month to worst, which is wide. An annual average tells you very little about the week you are actually flying, so read the strip rather than the headline if your dates are fixed.
October 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 253 flights.
Across the week, Tuesday is the strongest day at 90.5% on time and Saturday the weakest at 83.7%, a spread of 7 points.
Delay causes
Why this route gets delayed
Carrier accounts for 42% of the 17,000 delay minutes carriers reported here, and the remaining four split what is left.
- 42%Carrier
- 40%Late-arriving aircraft
- 18%National Airspace System
- 0%Security
40% of delay minutes trace back to a late-arriving aircraft, meaning the plane was already behind before it got here. Across 17,000 reported delay minutes here, that single category outweighs weather by 40 to one. The split is drawn from 16,968 reported delay minutes.
The largest share of delay minutes, 42%, falls under carrier control: crew scheduling, maintenance, fuelling, baggage. It accounts for 7,138 of the 17,000 delay minutes reported here.
Cancellations are rare at 0.53%, 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 actually costs
Badly late arrivals are rare here: only 3.4% 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 84.1% on time across 2,460 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 2,461 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.
Work out the risk of missing a connection in IAD after this flight
What to do with this
Booking this route
Put together: the calendar is the biggest lever here, not the carrier or the hour. October 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. 2,439 completed flights over 12 months sit behind that.
Common questions
LAX to IAD questions
How often is LAX to IAD delayed?
About one flight in eight arrives at least 15 minutes late, which is the Department of Transportation's definition of a delayed arrival. That works out to 12.5% of the 2,461 flights in this analysis, against 22.7% nationally. Delayed flights are late by about an hour on average.
How reliable is LAX to IAD compared with the rest of the country?
87.5% of flights arrive on time here against a national 77.3%, a difference of 10 points in its favour. That is worth a A+ on this site's grading scale.
What time of day has the fewest delays on LAX to IAD?
The 5am–8am departure window is the strongest at 95.9% on time. The 8am–11am window is the weakest at 85.1%, 11 points behind. Later departures inherit delays from earlier flights the same aircraft has already flown, which is why the curve slopes the way it does.
How bad are March delays on LAX to IAD?
March is the weakest month at 75.8% on time, compared with 96.0% in October. Across the year that is 20 points between the best and worst months. Moving flexible dates out of that month is one of the few things that reliably helps.
Related
Where to go next
- IAD to LAX — the return legseparate record
- Los Angeles International (LAX) delay statistics
- Washington Dulles International (IAD) delay statistics
- United Airlines on LAX to IAD88.0%
- American Airlines on LAX to IAD76.5%
- LAX to SFO, a related route60.1%
- ATL to IAD, a related route76.4%
- LAX to JFK, a related route77.5%
- United Airlines on-time record88.0%
- American Airlines on-time record76.5%
- Why the first flight of the morning is statistically safest
- The best time of day to fly, according to 7.05 million flight records
Direction matters. LAX to IAD and IAD to LAX are scored separately because they are separate operations, with different departure banks and different aircraft. Compare the return leg.
Embed LAX to IAD’s on-time badge on your site
Paste this into a web page. The badge shows the current on-time rate, cancellation rate and grade, and updates every month. Preview it, or build a badge for another route or airport.
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.