Carrier route record

AABOS→PHL

American Airlines · Boston to Philadelphia

Flights: 2,249
Period: July 2025 to June 2026
Share of route: 45%
Carriers: 4

Historical statistics for July 2025 to June 2026, not live status. For today’s flights, check with American Airlines.

American on BOS to PHL sits in the middle of the pack with a B. Close to three flights in four arrive on time by the DOT's definition, 2 points worse than the national rate of 77.6%. The late ones land close to two hours behind schedule. That rests on 2,249 flights. The strongest carrier on the route with a full sample, Republic Airways, flew 1,763 at 79.1% on time.

The US average over the same twelve months is 77.6%, so there is little to separate American on BOS to PHL from the country as a whole. The variation that matters here is internal: which carrier, and what time of day.

On time

75.9%

Arrivals under 15 minutes late, of 2,184 completed flights

Avg delay

109 min

Across delayed arrivals only, not all flights

Cancelled

2.85%

National rate is 1.81%

Whole route

76.5%

Every carrier on BOS to PHL, 4,961 flights

These figures cover 2,249 flights between July 2025 and June 2026. Beyond the headline rate, 11.4% of arrivals land a full hour or more behind schedule. That is the number that wrecks a connection, and it is not visible in an on-time percentage alone.

Carrier by carrier

American against every carrier on BOS to PHL

American flew 2,249 of the 4,961 flights on BOS to PHL, about 45% of it. Its 75.9% on time is about level with the route as a whole at 76.5%. Ranked by on-time rate it is number three of four carriers on the route, where the range runs from Frontier at 82.1% to JetBlue at 72.3%. One of those carriers flew fewer than 365 flights here, so treat their positions as rough.

The choice of carrier is not cosmetic here. Republic Airways arrives on time 79.1% of the time; JetBlue Airways manages 72.3%. Sample sizes sit next to every figure, because a two-point gap across 892 flights means less than a ten-point one.

On-time performance by carrier on BOS to PHL
Airline	Flights	On time	Avg delay	Cancelled	Grade
Frontier Airlinesthin sample	57	82.1%	55 min	1.75%	B
Republic Airways	1,763	79.1%	69 min	3.29%	B−
American Airlines (this page)	2,249	75.9%	109 min	2.85%	B
JetBlue Airways	892	72.3%	68 min	2.47%	C

Republic Airways cancels 3.3% of what it schedules here, the highest in the table. A cancelled flight never appears in an on-time rate, so read that column alongside the punctuality one rather than after it.

Departure window

When American runs best on this route

Departure time matters more here than the choice of carrier. The gap between the best and worst window is 38 points, against 7 points between the best and worst carrier. Each bar is the on-time rate for flights scheduled inside that window.

5am–8am523 flights93.1%
8am–11am480 flights86.1%
11am–2pm445 flights75.9%
2pm–5pm326 flights60.1%
5pm–8pm421 flights57.2%
8pm–5am54 flights54.7%

Scale runs 45% to 100%. Rows with fewer than 30 flights show a dash.

The 8pm–5am window is where this operation falls apart: 54.7% on time, against 93.1% 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 5am–8am window is the busiest, with 523 flights scheduled in it.

Across the year

American on BOS to PHL through the year

Darker means more delays. Figures are on-time percentages.November best, October worst

November is the best month on the calendar at 86.0% 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 243 flights.

Across the week, Saturday is the strongest day at 84.2% on time and Sunday the weakest at 69.9%. 14 points is a smaller lever than departure hour, but it is free.

Delay causes

Why American runs late on this route

One category carries most of the weight here. Late-arriving aircraft accounts for 58% of the 57,000 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
58%
Carrier
29%
National Airspace System
11%
Extreme weather
2%
Security
0%

58% 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 57,000 reported delay minutes here, that single category outweighs weather by 33 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 57,277 reported delay minutes.

The practical consequence: the 5am–8am departure is the one that starts clean. Its aircraft has no earlier leg to be late from, which is exactly why that window shows 93.1% on time here.

Cancellations run at 2.85%, against 1.81% nationally. That is roughly one flight in 40 cancelled outright. A cancelled flight is invisible in every on-time figure on this page, so the punctuality numbers above describe only the flights that actually operated.

Connections and stage length

What a delay here costs

For anyone connecting, the number to weigh is not the on-time rate but the tail behind it. 11.4% of arrivals land a full hour or more behind schedule, against 8.1% nationally. A 45-minute layover does not survive that, and no amount of walking quickly changes it. Ninety minutes is the honest minimum here, and two hours if the onward flight is on a separate ticket.

At 280 miles this is a short hop, and stage length matters more than it looks. A flight this short spends under two hours in the air, which leaves almost nothing to claw back a late pushback with. Delay here is decided on the ground, in the turn, which is why the 5am–8am window matters as much as it does.

The return leg is a different operation and performs like one: it runs 71.4% on time across 2,246 flights, 5 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 5 points of difference.

The sample behind these figures is 2,249 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 American on BOS to PHL

Put together: the delay figures matter less here than the 2.85% cancellation rate. A late arrival costs you close to two hours; a cancelled flight costs you the day. Book the 5am–8am departure so there is still a schedule behind you if it goes wrong, and treat a same-day connection as optimistic. 2,184 completed flights over 12 months sit behind that.

Where to go next

Source: US DOT Bureau of Transportation Statistics, on-time performance data, July 2025 to June 2026. Last updated 15 September 2026; recomputed monthly. How this data is collected.

Key figures