Route reliability record
SFO→PHL
San Francisco to Philadelphia
- Flights
- 2,082
- Period
- September 2025 to August 2026
- Distance
- 2,522 mi
- Carriers
- 2
This route earns an A. More than four flights in five arrive inside the 15-minute window the DOT uses to define an on-time arrival, which puts it 8 points better than the national rate of 77.3%. When something does go wrong the average delay runs an hour and a half. That rests on 2,082 SFO to PHL flights, of which American Airlines flew 1,333 at 85.4% on time.
Best time to fly SFO to PHL: a 5am–8am departure, ideally on a Tuesday. Flights in that window arrived on time 95.5% of the time and Tuesday flights 87.5%, against 85.2% for the route overall.
Set against the rest of the country, this route's record is 8 points better than the US average of 77.3%. That gap is worth roughly 79 fewer late arrivals for every thousand flights.
Key figures
On time
85.2%
Arrivals under 15 minutes late, of 2,050 completed flights
Avg delay
86 min
Across delayed arrivals only, not all flights
Cancelled
1.34%
National rate is 1.89%
Best carrier
American
85.4% on time across 1,333 flights
These figures cover 2,082 flights between September 2025 and August 2026. The median arrival is 11 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.
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Carrier by carrier
Which airline is most reliable on SFO to PHL
The two carriers here are closely matched: half a point separate the best from the worst. At that spread, schedule and price are better tie-breakers than reliability. Sample sizes are shown so you can see which rows are worth weighing.
| Airline | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| American Airlines | 1,333 | 85.4% | 107 min | 1.80% | A |
| United Airlines | 749 | 84.8% | 49 min | 0.53% | B+ |
No carrier stands out. American tops the table at 85.4%, half a point clear of the bottom, which is inside the range this kind of sample moves year to year.
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Best ways to make this trip
The most reliable ways to fly San Francisco to Philadelphia
Every airline on this route, ranked by how often a scheduled flight actually operated and arrived on time, with its best departure time and most punctual flight number. No nearby airport pair beat these.
| Option | Airline | Success | On time | Cancelled | Best departure | Most punctual flight |
|---|---|---|---|---|---|---|
| 1. SFO → PHLSan Francisco to Philadelphia | United Airlines | 84.4% | 84.8% | 0.53% | 8am–11am, Tue | — |
| 2. SFO → PHLSan Francisco to Philadelphia | American Airlines | 83.9% | 85.4% | 1.80% | 5am–8am, Thu | — |
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 30 points, against half a point between the best and worst carrier.
- 5am–8am386 flights95.5%
- 8am–11am525 flights82.8%
- 11am–2pm358 flights81.0%
- 2pm–5pm58 flights65.5%
- 5pm–8pm—
- 8pm–5am755 flights85.1%
Scale runs 55% to 100%. Rows with fewer than 30 flights show a dash.
Book the early departure. Flights leaving between 5am–8am arrive on time 95.5% of the time, against 65.5% for the afternoon window. That is 30 points of difference for no extra money, and it comes from the same aircraft having had no earlier flight to fall behind on. The 8pm–5am window is the busiest, with 755 flights scheduled in it.
Explore
Filter SFO to PHL 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 SFO to PHL, the best departure window is 5am–8am at 95.5% on time and the worst is 2pm–5pm at 65.5%, a wide gap of 30.0 points. All US flights leaving 5am–8am ran 89.3%.
- 5–8am95.5%
- 8–11am82.8%
- 11am–2pm81.0%
- 2–5pm65.5%
- 5–8pm—
- 8pm–5am85.1%
best all US flightsScale 55% to 100%. Cells under 30 flights show a dash.
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.
July is the worst month at 74.1% on time, 21 points below February, the best at 94.6%. 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 234 flights.
Across the week, Tuesday is the strongest day at 87.5% on time and Monday the weakest at 83.5%, a spread of 4 points.
Delay causes
Why this route gets delayed
Late-arriving aircraft accounts for 44% of the 26,000 delay minutes carriers reported here, and the remaining four split what is left.
- 44%Late-arriving aircraft
- 41%Carrier
- 12%National Airspace System
- 3%Extreme weather
- 0%Security
44% of delay minutes trace back to a late-arriving aircraft, meaning the plane was already behind before it got here. Across 26,000 reported delay minutes here, that single category outweighs weather by 17 to one. The split is drawn from 26,032 reported delay minutes.
The largest share of delay minutes, 41%, falls under carrier control: crew scheduling, maintenance, fuelling, baggage. It accounts for 11,000 of the 26,000 delay minutes reported here.
Cancellations sit at 1.34% against a national 1.89%, which is ordinary. Diversions add another 0.19%.
Connections and stage length
What a delay here actually costs
Badly late arrivals are rare here: only 4.6% land an hour or more behind schedule, against 8.3% nationally. Connections built on this flight are about as safe as US domestic connections get, though a cancelled flight still ignores every layover you give it.
At 2,522 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 is a different operation and performs like one: it runs 71.9% on time across 2,085 flights, 13 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 13 points of difference.
The sample behind these figures is 2,082 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 PHL after this flight
What to do with this
Booking this route
Put together: the calendar is the biggest lever here, not the carrier or the hour. February runs 94.6% on time and July 74.1%, a swing of 21 points. If the dates move at all, move them out of July before you think about anything else. 2,050 completed flights over 12 months sit behind that.
Common questions
SFO to PHL questions
How often is SFO to PHL delayed?
About one flight in seven arrives at least 15 minutes late, which is the Department of Transportation's definition of a delayed arrival. That works out to 14.8% of the 2,082 flights in this analysis, against 22.7% nationally. Delayed flights are late by an hour and a half on average.
Which airline is most reliable on SFO to PHL?
American Airlines leads at 85.4% on time across 1,333 flights. United Airlines is at the other end on 84.8%, a gap of half a point. 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 SFO to PHL?
The 5am–8am departure window is the strongest at 95.5% on time. The 2pm–5pm window is the weakest at 65.5%, 30 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 SFO to PHL?
July is the weakest month at 74.1% on time, compared with 94.6% in February. 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
- PHL to SFO — the return legseparate record
- San Francisco International (SFO) delay statistics
- Philadelphia International (PHL) delay statistics
- American Airlines on SFO to PHL85.4%
- United Airlines on SFO to PHL84.8%
- SFO to LAX, a related route70.9%
- ATL to PHL, a related route74.6%
- SFO to SEA, a related route72.3%
- American Airlines on-time record85.4%
- United Airlines on-time record84.8%
- Why the first flight of the morning is statistically safest
- The best time of day to fly, according to 7.05 million flight records
Direction matters. SFO to PHL and PHL to SFO 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.