Route reliability record
PHL→BOS
Philadelphia to Boston
- Flights
- 5,035
- Period
- September 2025 to August 2026
- Distance
- 280 mi
- Carriers
- 4
This route carries a cancellation problem, not just a delay problem: 3.4% of scheduled flights never operate, against 1.9% nationally. Of the ones that do fly, close to three flights in four arrive on time, worth a C− overall. The punctuality figure counts only flights that actually departed, so it flatters an operation that cancels this often. That rests on 5,035 PHL to BOS flights, of which Republic Airways flew 1,822 at 80.3% on time.
Best time to fly PHL to BOS: a 5am–8am departure, ideally on a Saturday. Flights in that window arrived on time 91.6% of the time and Saturday flights 81.6%, against 74.5% for the route overall.
Republic Airways is the most reliable of the three carriers covered here at 80.3% on time across 1,822 flights.
Key figures
On time
74.5%
Arrivals under 15 minutes late, of 4,863 completed flights
Avg delay
81 min
Across delayed arrivals only, not all flights
Cancelled
3.42%
National rate is 1.89%
Best carrier
Republic
80.3% on time across 1,822 flights
These figures cover 5,035 flights between September 2025 and August 2026. Beyond the headline rate, 12.3% of arrivals land a full hour or more behind schedule, against 8.3% nationally.
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Carrier by carrier
Which airline is most reliable on PHL to BOS
The choice of carrier is not cosmetic here. Republic Airways arrives on time 80.3% of the time; American Airlines manages 70.6%. Sample sizes sit next to every figure, because a two-point gap across 2,289 flights means less than a ten-point one.
| Airline | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| Frontier Airlinesthin sample | 32 | 90.6% | 52 min | 0.00% | A+ |
| Republic Airways | 1,822 | 80.3% | 78 min | 4.01% | B− |
| JetBlue Airways | 892 | 72.3% | 76 min | 3.81% | C− |
| American Airlines | 2,289 | 70.6% | 84 min | 2.84% | C |
Republic Airways cancels 4.0% 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.
Flight by flight
Flights on PHL to BOS
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.
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Best ways to make this trip
The most reliable ways to fly Philadelphia to Boston
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. 1 of the top 4 use a different airport at one end.
| Option | Airline | Success | On time | Cancelled | Best departure | Most punctual flight |
|---|---|---|---|---|---|---|
| 1. PHL → PVDPhiladelphia to Providence | American Airlines | 78.3% | 80.3% | 2.44% | 8am–11am, Mon | — |
| 2. PHL → BOSPhiladelphia to Boston | Republic Airways | 77.1% | 80.3% | 4.01% | 5am–8am, Sat | YX 5740 06:00 |
| 3. PHL → BOSPhiladelphia to Boston | JetBlue Airways | 69.5% | 72.3% | 3.81% | 5am–8am, Sat | — |
| 4. PHL → BOSPhiladelphia to Boston | American Airlines | 68.6% | 70.6% | 2.84% | 5am–8am, Sat | AA 1874 22:20 |
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 33 points, against 10 points between the best and worst carrier.
- 5am–8am772 flights91.6%
- 8am–11am1,202 flights85.1%
- 11am–2pm775 flights76.9%
- 2pm–5pm725 flights62.7%
- 5pm–8pm1,024 flights58.9%
- 8pm–5am537 flights67.3%
Scale runs 50% to 95%.
The 5pm–8pm window is where this operation falls apart: 58.9% on time, against 91.6% 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 1,202 flights scheduled in it.
Explore
Filter PHL to BOS 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 PHL to BOS, the best departure window is 5am–8am at 91.6% on time and the worst is 5pm–8pm at 58.9%, a wide gap of 32.7 points. All US flights leaving 5am–8am ran 89.3%.
- 5–8am91.6%
- 8–11am85.1%
- 11am–2pm76.9%
- 2–5pm62.7%
- 5–8pm58.9%
- 8pm–5am67.3%
best all US flightsScale 50% to 95%.
Across the year
When delays peak on this route
This route's year swings by 23 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.
Delays peak in September, when the on-time rate falls to 60.7%. February is the strongest month at 83.4%. Moving a flexible trip across that boundary buys 23 points. August was the busiest month here, with 463 flights.
Across the week, Saturday is the strongest day at 81.6% on time and Monday the weakest at 69.9%, a spread of 12 points.
Delay causes
Why this route gets delayed
Late-arriving aircraft accounts for 42% of the 100,000 delay minutes carriers reported here, and the remaining four split what is left.
- 42%Late-arriving aircraft
- 30%National Airspace System
- 21%Carrier
- 6%Extreme weather
- 0%Security
42% of delay minutes trace back to a late-arriving aircraft, meaning the plane was already behind before it got here. Across 100,000 reported delay minutes here, that single category outweighs weather by 7 to one. The split is drawn from 99,742 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 91.6% on time here.
Cancellations run at 3.42%, against 1.89% nationally. That is about one flight in 30 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 actually costs
12.3% of arrivals land a full hour or more behind schedule, against 8.3% nationally. Ninety minutes is the honest minimum for a connection 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 runs 76.0% on time across 5,036 flights, within 2 points 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 5,035 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 BOS after this flight
What to do with this
Booking this route
Put together: the delay figures matter less here than the 3.42% cancellation rate. A late arrival costs you a little over an hour; 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. 4,863 completed flights over 12 months sit behind that.
Common questions
PHL to BOS questions
How often is PHL to BOS delayed?
About one flight in four arrives at least 15 minutes late, which is the Department of Transportation's definition of a delayed arrival. That works out to 25.5% of the 5,035 flights in this analysis, against 22.7% nationally. Delayed flights are late by a little over an hour on average.
Which airline is most reliable on PHL to BOS?
Republic Airways leads at 80.3% on time across 1,822 flights. American Airlines is at the other end on 70.6%, a gap of 10 points. Sample size matters as much as the percentage: a rate built from a few hundred flights moves around far more than one built from ten thousand.
What time of day has the fewest delays on PHL to BOS?
The 5am–8am departure window is the strongest at 91.6% on time. The 5pm–8pm window is the weakest at 58.9%, 33 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 September delays on PHL to BOS?
September is the weakest month at 60.7% on time, compared with 83.4% in February. Across the year that is 23 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
- BOS to PHL — the return legseparate record
- Philadelphia International (PHL) delay statistics
- Boston Logan International (BOS) delay statistics
- Republic Airways on PHL to BOS80.3%
- JetBlue Airways on PHL to BOS72.3%
- American Airlines on PHL to BOS70.6%
- PHL to ATL, a related route78.0%
- DCA to BOS, a related route70.1%
- PHL to MCO, a related route72.4%
- Frontier Airlines on-time record90.6%
- Republic Airways on-time record80.3%
- JetBlue Airways on-time record72.3%
- The US routes with the most cancellations
- Why the first flight of the morning is statistically safest
Direction matters. PHL to BOS and BOS to PHL are scored separately because they are separate operations, with different departure banks and different aircraft. Compare the return leg.
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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.