Route reliability record
IND→PHL
Indianapolis to Philadelphia
- Flights
- 1,549
- Period
- July 2025 to June 2026
- Distance
- 588 mi
- Carriers
- 3
This route lands a B−, 2 points better than the national rate of 77.6%. About one flight in five arrives 15 minutes late or worse, and those flights are late by an hour and a half on average. That is a workable record, not a spotless one. That rests on 1,549 IND to PHL flights, of which Republic Airways flew 602 at 89.6% on time.
Best time to fly IND to PHL: a 5am–8am departure, ideally on a Tuesday. Flights in that window arrived on time 92.1% of the time and Tuesday flights 85.3%, against 79.7% for the route overall.
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
79.7%
Arrivals under 15 minutes late, of 1,499 completed flights
Avg delay
93 min
Across delayed arrivals only, not all flights
Cancelled
3.03%
National rate is 1.81%
Best carrier
Republic
89.6% on time across 602 flights
These figures cover 1,549 flights between July 2025 and June 2026. The median arrival is 10 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 IND to PHL
The choice of carrier is not cosmetic here. Republic Airways arrives on time 89.6% of the time; American Airlines manages 70.9%. Sample sizes sit next to every figure, because a two-point gap across 612 flights means less than a ten-point one.
| Airline | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| Republic Airways | 602 | 89.6% | 58 min | 1.83% | A |
| PSA Airlinesthin sample | 335 | 77.6% | 101 min | 6.57% | B− |
| American Airlines | 612 | 70.9% | 103 min | 2.29% | C |
The spread between Republic and American is 19 points, wide enough that it should decide the booking. On a hundred trips that is 19 more arrivals inside the on-time window.
Best ways to make this trip
The most reliable ways to fly Indianapolis 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. IND → PHLIndianapolis to Philadelphia | Republic Airways | 88.0% | 89.6% | 1.83% | 5am–8am, Tue | — |
| 2. IND → PHLIndianapolis to Philadelphia | American Airlines | 69.3% | 70.9% | 2.29% | 5am–8am, Wed | — |
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 24 points, against 19 points between the best and worst carrier. Each bar is the on-time rate for flights scheduled inside that window.
- 5am–8am453 flights92.1%
- 8am–11am74 flights89.2%
- 11am–2pm432 flights80.6%
- 2pm–5pm370 flights67.7%
- 5pm–8pm220 flights68.6%
- 8pm–5am—
Scale runs 60% to 100%. Rows with fewer than 30 flights show a dash.
Book the early departure. Flights leaving between 5am–8am arrive on time 92.1% of the time, against 67.7% for the afternoon window. That is 24 points of difference for no extra money, and it comes from the same aircraft having had no earlier flight to fall behind on. The 5am–8am window is the busiest, with 453 flights scheduled in it.
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.
July is the worst month at 67.5% on time, 23 points below February, the best at 90.6%. 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. June was the busiest month here, with 172 flights.
Across the week, Tuesday is the strongest day at 85.3% on time and Thursday the weakest at 75.4%. 10 points is a smaller lever than departure hour, but it is free.
Delay causes
Why this route gets delayed
One category carries most of the weight here. Late-arriving aircraft accounts for 51% of the 28,000 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.
- 51%Late-arriving aircraft
- 30%Carrier
- 16%National Airspace System
- 3%Extreme weather
- 0%Security
51% 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 28,000 reported delay minutes here, that single category outweighs weather by 17 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 28,473 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 92.1% on time here.
Cancellations run at 3.03%, against 1.81% nationally. That is roughly 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
7.0% 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 last an hour and a half, which a normal layover absorbs.
The 588 miles between these two airports put this in the middle of the US network, around two and a half to three hours of block time. That is enough cruise to absorb a ten-minute late pushback and not enough to absorb thirty. It is also long enough that the aircraft usually flies three or four legs a day rather than six, which slows how fast delay compounds.
The return leg is a different operation and performs like one: it runs 75.9% on time across 1,549 flights, 4 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 4 points of difference.
The sample behind these figures is 1,549 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 delay figures matter less here than the 3.03% cancellation rate. A late arrival costs you an hour and a half; 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. 1,499 completed flights over 12 months sit behind that.
Common questions
IND to PHL questions
How often is IND to PHL delayed?
About one flight in five arrives at least 15 minutes late, which is the Department of Transportation's definition of a delayed arrival. That works out to 20.3% of the 1,549 flights in this analysis, against 22.4% nationally. Delayed flights are late by an hour and a half on average.
Which airline is most reliable on IND to PHL?
Republic Airways leads at 89.6% on time across 602 flights. American Airlines is at the other end on 70.9%, a gap of 19 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 IND to PHL?
The 5am–8am departure window is the strongest at 92.1% on time. The 2pm–5pm window is the weakest at 67.7%, 24 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 IND to PHL?
July is the weakest month at 67.5% on time, compared with 90.6% 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
- PHL to IND — the return legseparate record
- Indianapolis International (IND) delay statistics
- Philadelphia International (PHL) delay statistics
- Republic Airways on IND to PHL89.6%
- PSA Airlines on IND to PHL77.6%
- American Airlines on IND to PHL70.9%
- IND to ORD, a related route76.5%
- ATL to PHL, a related route74.9%
- IND to ATL, a related route88.5%
- Republic Airways on-time record89.6%
- PSA Airlines on-time record77.6%
- American Airlines on-time record70.9%
- The US routes with the most cancellations
- Why the first flight of the morning is statistically safest
Direction matters. IND to PHL and PHL to IND 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, July 2025 to June 2026. Last updated 15 September 2026; recomputed monthly. How this data is collected.