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DelayAtlas

Route reliability record

LAXPHL

Los Angeles to Philadelphia

Flights
2,412
Period
July 2025 to June 2026
Distance
2,402 mi
Carriers
3
BGRADE

This route lands a B, about a point better than 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 2,412 flights, with a median arrival 9 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

78.7%

Arrivals under 15 minutes late, of 2,367 completed flights

Avg delay

79 min

Across delayed arrivals only, not all flights

Cancelled

1.66%

National rate is 1.81%

Best carrier

American

79.8% on time across 2,322 flights

These figures cover 2,412 flights between July 2025 and June 2026. The median arrival is 9 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 LAX to PHL

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.

On-time performance by carrier on LAX to PHL
AirlineFlightsOn timeAvg delayCancelledGrade
American Airlines2,32279.8%80 min1.59%B
Spirit Airlinesthin sample475.0%15 min0.00%B+
Frontier Airlinesthin sample8650.6%77 min3.49%F−

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 15 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–8am460 flights88.2%
  • 8am–11am378 flights76.6%
  • 11am–2pm350 flights73.3%
  • 2pm–5pm465 flights74.0%
  • 5pm–8pm
  • 8pm–5am759 flights79.5%

Scale runs 65% to 95%. Rows with fewer than 30 flights show a dash.

The weak window here is the middle of the day, not the evening: 11am–2pm runs 73.3% on time against 88.2% for 5am–8am. That shape usually means a departure bank rather than an accumulating delay, so the recovery later in the afternoon is real rather than noise. The 8pm–5am window is the busiest, with 759 flights scheduled in it.

Across the year

When delays peak on this route

This route's year swings by 22 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.

On-time rate by calendar month75J82F81M86A84M80J64J77A81S82O73N82D
Darker means more delays. Figures are on-time percentages.April best, July worst

July is the worst month at 64.4% on time, 22 points below April, the best at 86.3%. Summer afternoon convection and peak-season schedules land on the same weeks every year, so this is a pattern you can book around rather than a run of bad luck. July was the busiest month here, with 264 flights.

Across the week, Tuesday is the strongest day at 81.1% on time and Sunday the weakest at 76.0%. 5 points is a smaller lever than departure hour, but it is free.

On-time rate by day of the week79.2Mon81.1Tue78.8Wed76.6Thu80.5Fri79.0Sat76.0Sun
Monday: 79.2 percent on time. Tuesday: 81.1 percent on time. Wednesday: 78.8 percent on time. Thursday: 76.6 percent on time. Friday: 80.5 percent on time. Saturday: 79.0 percent on time. Sunday: 76.0 percent on time

Delay causes

Why this route gets delayed

One category carries most of the weight here. Late-arriving aircraft accounts for 52% of the 40,000 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.

  • Late-arriving aircraft
    52%
  • Carrier
    36%
  • National Airspace System
    11%
  • Security
    0%
  • Extreme weather
    0%

52% 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 40,000 reported delay minutes here, that single category outweighs weather by 52 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 39,859 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 14,000 of the 40,000 delay minutes reported here.

Cancellations sit at 1.66% against a national 1.81%, which is ordinary. Diversions add another 0.21%.

Connections and stage length

What a delay here actually costs

7.4% 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 78.3% on time across 2,418 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 2,412 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. April runs 86.3% on time and July 64.4%, a swing of 22 points. If the dates move at all, move them out of July before you think about anything else. 2,367 completed flights over 12 months sit behind that.

Common questions

LAX to PHL questions

How often is LAX to PHL 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 21.3% of the 2,412 flights in this analysis, against 22.4% nationally. Delayed flights are late by a little over an hour on average.

How reliable is LAX to PHL compared with the rest of the country?

78.7% of flights arrive on time here against a national 77.6%, a difference of about 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 LAX to PHL?

The 5am–8am departure window is the strongest at 88.2% on time. The 11am–2pm window is the weakest at 73.3%, 15 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 July delays on LAX to PHL?

July is the weakest month at 64.4% on time, compared with 86.3% in April. Across the year that is 22 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

Source: US DOT Bureau of Transportation Statistics, on-time performance data, July 2025 to June 2026. Updated monthly. How this data is collected.