Route reliability record
PHL→ORD
Philadelphia to Chicago
- Flights
- 5,075
- Period
- September 2025 to August 2026
- Distance
- 678 mi
- Carriers
- 4
This route carries a cancellation problem, not just a delay problem: 3.6% 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 5,075 PHL to ORD flights, of which American Airlines flew 3,007 at 74.8% on time.
Best time to fly PHL to ORD: a 5am–8am departure, ideally on a Tuesday. Flights in that window arrived on time 86.2% of the time and Tuesday flights 79.2%, against 73.1% for the route overall.
The national on-time rate over the same period is 77.3%, so this route runs 4 points behind the country as a whole. Across a thousand flights that is about 42 extra late arrivals.
Key figures
On time
73.1%
Arrivals under 15 minutes late, of 4,867 completed flights
Avg delay
102 min
Across delayed arrivals only, not all flights
Cancelled
3.59%
National rate is 1.89%
Best carrier
American
74.8% on time across 3,007 flights
These figures cover 5,075 flights between September 2025 and August 2026. Beyond the headline rate, 11.9% 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 ORD
The two carriers here are closely matched: 3 points 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 |
|---|---|---|---|---|---|
| Republic Airwaysthin sample | 26 | 92.3% | 44 min | 0.00% | A+ |
| American Airlines | 3,007 | 74.8% | 99 min | 4.49% | C− |
| United Airlines | 1,846 | 71.9% | 105 min | 2.00% | C |
| Frontier Airlinesthin sample | 196 | 56.2% | 118 min | 5.10% | D− |
American Airlines cancels 4.5% 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 ORD
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 Chicago
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 3 use a different airport at one end.
| Option | Airline | Success | On time | Cancelled | Best departure | Most punctual flight |
|---|---|---|---|---|---|---|
| 1. PHL → ORDPhiladelphia to Chicago | American Airlines | 71.4% | 74.8% | 4.49% | 5am–8am, Tue | — |
| 2. PHL → MDWPhiladelphia to Chicago | Southwest Airlines | 71.3% | 72.6% | 1.85% | 5am–8am, Wed (route) | — |
| 3. PHL → ORDPhiladelphia to Chicago | United Airlines | 70.5% | 71.9% | 2.00% | 5am–8am, Tue | UA 308 17:00 |
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 3 points between the best and worst carrier.
- 5am–8am921 flights86.2%
- 8am–11am1,087 flights80.1%
- 11am–2pm948 flights76.1%
- 2pm–5pm584 flights70.3%
- 5pm–8pm1,203 flights56.3%
- 8pm–5am332 flights70.6%
Scale runs 50% to 90%.
The 5pm–8pm window is where this operation falls apart: 56.3% on time, against 86.2% 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 5pm–8pm window is the busiest, with 1,203 flights scheduled in it.
Explore
Filter PHL to ORD 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 ORD, the best departure window is 5am–8am at 86.2% on time and the worst is 5pm–8pm at 56.3%, a wide gap of 29.9 points. All US flights leaving 5am–8am ran 89.3%.
- 5–8am86.2%
- 8–11am80.1%
- 11am–2pm76.1%
- 2–5pm70.3%
- 5–8pm56.3%
- 8pm–5am70.6%
best all US flightsScale 50% to 95%.
Across the year
When delays peak on this route
This route's year swings by 17 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.
December is the weak month at 65.0% on time, against 82.3% in February. Winter delays cluster: a single storm system can account for most of a month's shortfall, so an average December hides both very good weeks and genuinely unflyable days. August was the busiest month here, with 512 flights.
Across the week, Tuesday is the strongest day at 79.2% on time and Sunday the weakest at 67.7%, a spread of 12 points.
Delay causes
Why this route gets delayed
Carriers report a reason for every delay minute they cause, in five DOT categories. The split below is by minutes, not by number of flights, so a handful of very long weather delays weighs as much as many short ones. It covers 134,000 reported delay minutes.
- 38%National Airspace System
- 36%Late-arriving aircraft
- 22%Carrier
- 5%Extreme weather
- 0%Security
36% of delay minutes trace back to a late-arriving aircraft, meaning the plane was already behind before it got here. Across 134,000 reported delay minutes here, that single category outweighs weather by 8 to one. The split is drawn from 133,871 reported delay minutes.
38% of delay minutes are charged to the National Airspace System: air traffic volume, runway configuration, ground stops. No carrier can price its way out of that, which is why airport choice moves the number here more than carrier choice does. That is 51,000 minutes out of 134,000, against a national NAS share of 21%.
Cancellations run at 3.59%, 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
11.9% 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.
The 678 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.
The return leg runs 70.8% on time across 5,082 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 5,075 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 ORD after this flight
What to do with this
Booking this route
Put together: the delay figures matter less here than the 3.59% 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. 4,867 completed flights over 12 months sit behind that.
Common questions
PHL to ORD questions
How often is PHL to ORD 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 26.9% of the 5,075 flights in this analysis, against 22.7% nationally. Delayed flights are late by close to two hours on average.
Which airline is most reliable on PHL to ORD?
American Airlines leads at 74.8% on time across 3,007 flights. United Airlines is at the other end on 71.9%, a gap of 3 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 ORD?
The 5am–8am departure window is the strongest at 86.2% on time. The 5pm–8pm window is the weakest at 56.3%, 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 December delays on PHL to ORD?
December is the weakest month at 65.0% on time, compared with 82.3% in February. Across the year that is 17 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
- ORD to PHL — the return legseparate record
- Philadelphia International (PHL) delay statistics
- Chicago O'Hare International (ORD) delay statistics
- American Airlines on PHL to ORD74.8%
- United Airlines on PHL to ORD71.9%
- Frontier Airlines on PHL to ORD56.2%
- PHL to ATL, a related route78.0%
- LGA to ORD, a related route66.7%
- PHL to MCO, a related route72.4%
- Republic Airways on-time record92.3%
- American Airlines on-time record74.8%
- United Airlines on-time record71.9%
- The US routes with the most cancellations
- Why the first flight of the morning is statistically safest
Direction matters. PHL to ORD and ORD 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.