Route profile
IAD→LAX
Flight reliability, delays and best times to fly from Washington to Los Angeles, 2,288 miles.
Right now
Aviation weather is not currently a factor.
Aviation weather is not currently a factor.
Route reliability
July 2023 – July 2026
Better than 73% of comparable major US routes (4,598 compared)
Calculated from 7,816 flights. How this is calculated
IAD → LAX arrives on time 81.8% of the time; the return trip, LAX → IAD, arrives on time 85.4% of the time, a 3.6-point gap between the two directions of the same city pair.
IAD → LAX spends 32.0 minutes on the ground on a 2,288-mile trip: 20.9 minutes from pushback to wheels-up at IAD and 11.1 minutes from touchdown to gate at LAX.
Source: US DOT Bureau of Transportation Statistics · Data covering July 2023 – July 2026
What sets this route apart
Where IAD to LAX differs most from similar routes by hour, weekday, month and airline, July 2023 – July 2026.
IAD to LAX is at its best against routes of similar length for flights scheduled at 12 PM: 91.6% arrive on time, 14 points ahead of the 77.6% those routes manage at that hour. Against all other routes the gap is 12.2 points.
IAD to LAX struggles most at 5 PM: 69.4% of its flights scheduled then arrive on time, 3.6 points behind the 73.0% on routes of similar length at the same hour.
IAD to LAX holds up on Mondays better than routes of similar length do: 84.1% on time to their 78.3%, a 5.8 points lead. Against all other routes the gap is 6.9 points.
December is kinder to IAD to LAX than to routes of similar length: 85.1% on time against 79.2%, 5.9 points better. Against all other routes the gap is 6.3 points.
Alaska Airlines’ flights on IAD to LAX arrive on time 71.4% of the time, 5 points below the 76.4% it manages on its routes of similar length. Against all other routes the gap is 6.6 points.
IAD to LAX against comparable routes
July 2023 – July 2026| Measure | This route | Compared with | Them | Gap | Flights behind it |
|---|---|---|---|---|---|
| Hour: 12 PM departures | 91.6% | routes of similar length | 77.6% | +14.0 pts | 943 here, 54,540 there |
| Hour: 5 PM departures | 69.4% | routes of similar length | 73.0% | −3.6 pts | 1,209 here, 65,661 there |
| Weekday: Monday | 84.1% | routes of similar length | 78.3% | +5.8 pts | 1,137 here, 172,964 there |
| Month: December | 85.1% | routes of similar length | 79.2% | +5.9 pts | 629 here, 94,803 there |
| Airline: Alaska Airlines | 71.4% | routes of similar length | 76.4% | −5.0 pts | 888 here, 162,804 there |
Each comparison pools the flights of other routes, with this route’s own left out. Similar length means within 15% of this route’s 2,288 miles, with at least 5 such routes. A bucket is set against the most comparable group that has enough flights: similar length, then the same origin (at least 3 routes), then all other routes. Hours, weekdays and months appear only where both sides have 120 completed flights, and airlines where both have 600. The gap must be at least 2 points and 2 standard errors, and only the largest gap each way is kept per measure. These are differences in the flights counted, not causes.
Why IAD → LAX flights are cancelled
July 2023 – July 2026
IAD → LAX cancelled 75 of 7,816 scheduled flights — about 1 in every 104. The reason filed most often was the airline, 81.3% of the cancellations coded on this route — about 1 in every 128 scheduled flights.
Share of cancellations
Of 75 cancelled departures carrying a reason code.
What each reason means
Crew, maintenance, aircraft cleaning, baggage or fueling: what BTS counts as within the carrier’s own control.
61 cancellations, 81.3% of the total.
Conditions the carrier judged severe enough to stop the flight: a blizzard, a hurricane, a line of thunderstorms.
14 cancellations, 18.7% of the total.
Airport capacity, air traffic control flow programs, heavy traffic and ordinary bad weather. A system decision, not the airline’s.
0 cancellations, 0.0% of the total.
A terminal evacuation, a security breach, screening equipment failure, or screening queues over 29 minutes.
0 cancellations, 0.0% of the total.
Reason codes are the operating airline’s own filing with US DOT, not an independent finding of fault. With only one or two carriers on the route, the split mostly reflects how they file. Ordinary bad weather is filed under air traffic, so weather’s full share is larger than its bar.
75 coded cancellations were recorded on IAD → LAX; the section appears from 50.
When it goes wrong
July 2023 – July 2026
33 min late
against a median of 8 min early
Percentiles over 7,816 operations; cancelled and diverted flights are counted separately.
Will your connection be tight enough?
Layovers at LAX after arriving from IAD.
| Connection time | Chance of missing | Reads as |
|---|---|---|
| 30 min | 33% | Likely to miss |
| 45 min | 17% | High risk |
| 60 min | 11% | Some risk |
| 90 min | 5.7% | Some risk |
| 120 min | 3.4% | Low risk |
This is one leg of a connection. Gate changes and the next flight's own schedule matter too. And a connection can fail before delay is even the question — this route cancels 0.96% of the time and diverts 0.14% of the time, which a late arrival never shows up in.
Chance of missing is the share of 7,730 arrivals on this route that landed later than the connection time less 30 minutes to reach the next gate.
The worst tenth of arrivals on this route land at least 33 minutes late (90th-percentile gate arrival delay), over 7,816 operations.
Any other layover length: connection checker.
Best time to fly
IAD → LAX flights departing 12–3 PM arrived on time 90.8% of the time, against 73.7% for 3–6 PM departures, a gap of 17.1 percentage points.
By departure window
By departure hour
- 12 AM to 5 AM: too few flights to score
- 6 AM: 88.3% on time from 576 flights
- 7 AM: 88.5% on time from 366 flights
- 8 AM: 86.6% on time from 886 flights
- 9 AM: 85.8% on time from 458 flights
- 10 AM to 11 AM: too few flights to score
- 12 PM: 91.6% on time from 958 flights
- 1 PM: 88.7% on time from 169 flights
- 2 PM: too few flights to score
- 3 PM: 81.4% on time from 416 flights
- 4 PM: 80.7% on time from 284 flights
- 5 PM: 69.4% on time from 1,222 flights
- 6 PM: 74.9% on time from 531 flights
- 7 PM: 79.6% on time from 525 flights
- 8 PM: 69.0% on time from 327 flights
- 9 PM: too few flights to score
- 10 PM: 83.2% on time from 972 flights
- 11 PM: too few flights to score
Why IAD → LAX runs late
July 2023 – July 2026
the inbound aircraft was late, so this flight started late
crew, maintenance, boarding and fueling, all within the carrier’s control
airspace and airport capacity, including weather-driven flow control
weather severe enough to stop this flight specifically
screening or terminal security incidents
Share of the delay minutes US DOT attributed to each cause for IAD → LAX. Only delays of 15 minutes or more are attributed.
Late-arriving aircraft is the largest cause on IAD → LAX, at 36.3%: flights here mostly leave late because the plane came in late, and the day shows it: 12–3 PM departures arrived on time 90.8% of the time and 3–6 PM departures 73.7%.
Airlines on this route
Carriers with at least 200 flights, by the airline that operated each one.
| Carrier | Flights | On time | Cancelled | Median delay | Severe |
|---|---|---|---|---|---|
| United Airlines | 6,806 | 83.3% | 1.01% | -9 min | 5.3% |
| Alaska Airlines | 895 | 71.4% | 0.67% | 0 min | 9.1% |
United Airlines flew 88.4% of the 7,701 flights listed.
United Airlines arrived on time 11.9 percentage points more often than Alaska Airlines on this route.
Flights on this route
Flight numbers with at least 600 operations here and still on the schedule.
Weekly and seasonal patterns
By day of week
Tuesday is historically the most reliable day and Saturday the least, a gap of 5.7 percentage points.
By month
- Jan: 76.9%
- Feb: 80.0%
- Mar: 84.4%
- Apr: 82.5%
- May: 81.2%
- Jun: 77.0%
- Jul: 73.3%
- Aug: 81.5%
- Sep: 87.1%
- Oct: 87.8%
- Nov: 88.5%
- Dec: 85.1%
July is historically the weakest month and November the strongest, a spread of 15.2 percentage points.
Reliability over time
July 2023 – July 2026
- July 2023: 68.0% from 236 flights
- August 2023: 83.2% from 244 flights
- September 2023: 77.7% from 198 flights
- October 2023: 83.4% from 217 flights
- November 2023: 89.1% from 193 flights
- December 2023: 89.9% from 188 flights
- January 2024: 78.7% from 145 flights
- February 2024: 81.4% from 146 flights
- March 2024: 78.9% from 214 flights
- April 2024: 77.2% from 232 flights
- May 2024: 74.2% from 242 flights
- June 2024: 83.3% from 236 flights
- July 2024: 81.6% from 248 flights
- August 2024: 82.0% from 236 flights
- September 2024: 93.4% from 215 flights
- October 2024: 90.4% from 240 flights
- November 2024: 89.0% from 229 flights
- December 2024: 80.3% from 230 flights
- January 2025: 75.3% from 160 flights
- February 2025: 79.6% from 144 flights
- March 2025: 89.8% from 205 flights
- April 2025: 89.7% from 242 flights
- May 2025: 81.5% from 254 flights
- June 2025: 65.9% from 226 flights
- July 2025: 60.0% from 224 flights
- August 2025: 79.0% from 196 flights
- September 2025: 90.2% from 174 flights
- October 2025: 89.6% from 202 flights
- November 2025: 87.2% from 198 flights
- December 2025: 85.9% from 215 flights
- January 2026: 77.0% from 174 flights
- February 2026: 79.1% from 158 flights
- March 2026: 84.8% from 184 flights
- April 2026: 80.2% from 224 flights
- May 2026: 87.6% from 252 flights
- June 2026: 81.2% from 253 flights
- July 2026: 81.8% from 242 flights
Over the most recent 12 months (2025-08 to 2026-07), on-time arrivals averaged 83.7% against 81.6% in the 12 months before — improving by 2.1 percentage points.
Data and methodology
Calculated by FlyerIntel from 7,816 IAD → LAX flight records from the US DOT Bureau of Transportation Statistics, covering July 2023 – July 2026. Late means 15 or more minutes past scheduled arrival; cancelled and diverted flights are left out of on-time rates.
Full methodology · Data sources · Report a problem
Related research: How Long a Layover Needs to Be · Two Airlines on One Route · Best Time of Day to Fly From Major US Airports
Analysis last recomputed