Route reliability record
PHL→LAX
Philadelphia to Los Angeles
- Flights
- 2,418
- Period
- July 2025 to June 2026
- Distance
- 2,402 mi
- Carriers
- 3
This route lands a B, level with the national rate of 77.6%. About one flight in five arrive 15 minutes late or worse, and those flights are late by a little over an hour on average. That is a workable record, not a spotless one. That rests on 2,418 flights, with a median arrival 6 minutes early.
The US average over the same twelve months is 77.6%, so there is little to separate this route from the country as a whole. The variation that matters here is internal: which carrier, and what time of day.
Key figures
On time
78.3%
Arrivals under 15 minutes late, of 2,378 completed flights
Avg delay
70 min
Across delayed arrivals only, not all flights
Cancelled
1.41%
National rate is 1.81%
Best carrier
American
78.7% on time across 2,329 flights
These figures cover 2,418 flights between July 2025 and June 2026. The median arrival is 6 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.
Carrier by carrier
Which airline is most reliable on PHL to LAX
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 |
|---|---|---|---|---|---|
| American Airlines | 2,329 | 78.7% | 71 min | 1.46% | B |
| Spirit Airlinesthin sample | 4 | 75.0% | 16 min | 0.00% | B+ |
| Frontier Airlinesthin sample | 85 | 67.1% | 66 min | 0.00% | C+ |
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 27 points, against half a point between the best and worst carrier. Each bar is the on-time rate for flights scheduled inside that window.
- 5am–8am350 flights89.4%
- 8am–11am633 flights86.0%
- 11am–2pm220 flights78.6%
- 2pm–5pm479 flights79.1%
- 5pm–8pm573 flights66.5%
- 8pm–5am163 flights62.1%
Scale runs 55% to 95%. Rows with fewer than 30 flights show a dash.
The 8pm–5am window is where this operation falls apart: 62.1% on time, against 89.4% for the 5am–8am slot. By evening the aircraft flying these rotations have absorbed a full day of small delays and there is no slack left to recover in. The 8am–11am window is the busiest, with 633 flights scheduled in it.
Across the year
When delays peak on this route
This route's year swings by 21 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.
December is the weak month at 66.5% on time, against 87.1% in September. Winter delays cluster: a single storm system can account for most of a month's shortfall, so an average December hides both very good weeks and genuinely unflyable days. July was the busiest month here, with 263 flights.
Across the week, Friday is the strongest day at 81.4% on time and Thursday the weakest at 74.0%. 7 points is a smaller lever than departure hour, but it is free.
Delay causes
Why this route gets delayed
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 36,000 reported delay minutes.
- 38%Late-arriving aircraft
- 36%Carrier
- 21%National Airspace System
- 5%Extreme weather
- 0%Security
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 36,000 reported delay minutes here, that single category outweighs weather by 8 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 36,360 reported delay minutes.
The largest share of delay minutes, 36%, falls under carrier control: crew scheduling, maintenance, fuelling, baggage. Unlike weather, that is a management outcome, and it is the category where the gap between two carriers on the same schedule is genuinely earned. It accounts for 13,000 of the 36,000 delay minutes reported here.
Cancellations sit at 1.41% against a national 1.81%, which is ordinary. Diversions add another 0.25%.
Connections and stage length
What a delay here actually costs
6.4% of arrivals land an hour or more late, close to the national 8.1%. That is the figure that decides a connection, and it says a 60 to 75 minute layover is reasonable here while anything under 45 minutes is a bet. Most delays on this route are the a little over an hour kind, which a normal layover absorbs.
At 2,402 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 runs 78.7% on time across 2,412 flights, within half a point of this direction. The two legs are scored separately because they usually differ; on this city pair they happen not to.
The sample behind these figures is 2,418 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 this route
Put together: the calendar is the biggest lever here, not the carrier or the hour. September runs 87.1% on time and December 66.5%, a swing of 21 points. If the dates move at all, move them out of December before you think about anything else. 2,378 completed flights over 12 months sit behind that.
Common questions
PHL to LAX questions
How often is PHL to LAX delayed?
About one flight in five arrive at least 15 minutes late, which is the Department of Transportation's definition of a delayed arrival. That works out to 21.7% of the 2,418 flights in this analysis, against 22.4% nationally. Delayed flights are late by a little over an hour on average.
How reliable is PHL to LAX compared with the rest of the country?
78.3% of flights arrive on time here against a national 77.6%, a difference of half a point in its favour. That is worth a B on this site's grading scale.
What time of day has the fewest delays on PHL to LAX?
The 5am–8am departure window is the strongest at 89.4% on time. The 8pm–5am window is the weakest at 62.1%, 27 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 December delays on PHL to LAX?
December is the weakest month at 66.5% on time, compared with 87.1% in September. Across the year that is 21 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
- LAX to PHL — the return legseparate record
- Philadelphia International (PHL) delay statistics
- Los Angeles International (LAX) delay statistics
- American Airlines on-time record78.7%
- Spirit Airlines on-time record75.0%
- Frontier Airlines on-time record67.1%
- Why the first flight of the morning is statistically safest
- The best time of day to fly, according to 7.04 million flight records
Direction matters. PHL to LAX and LAX to PHL are scored separately because they are separate operations, with different departure banks and different aircraft. Compare the return leg.
Source: US DOT Bureau of Transportation Statistics, on-time performance data, July 2025 to June 2026. Updated monthly. How this data is collected.