Carrier route record
UAPHL→ORD
United Airlines · Philadelphia to Chicago
- Flights
- 1,773
- Period
- July 2025 to June 2026
- Share of route
- 36%
- Carriers
- 4
Historical statistics for July 2025 to June 2026, not live status. For today’s flights, check with United Airlines.
United on PHL to ORD sits in the middle of the pack with a C. Close to three flights in four arrive on time by the DOT's definition, 4 points worse than the national rate of 77.6%. The late ones land an hour and a half behind schedule. That rests on 1,773 flights, with a median arrival 3 minutes early.
The US average over the same twelve months is 77.6%, so there is little to separate United on PHL to ORD from the country as a whole. The variation that matters here is internal: which carrier, and what time of day.
Key figures
On time
74.0%
Arrivals under 15 minutes late, of 1,734 completed flights
Avg delay
94 min
Across delayed arrivals only, not all flights
Cancelled
1.75%
National rate is 1.81%
Whole route
73.0%
Every carrier on PHL to ORD, 4,911 flights
These figures cover 1,773 flights between July 2025 and June 2026. Beyond the headline rate, 9.7% 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
United against every carrier on PHL to ORD
United flew 1,773 of the 4,911 flights on PHL to ORD, about 36% of it. Its 74.0% on time is about level with the route as a whole at 73.0%. Ranked by on-time rate it is number two of four carriers on the route, where the range runs from Republic at 92.3% to Frontier at 58.6%. Two of those carriers flew fewer than 365 flights here, so treat their positions as rough.
Only one carrier clears this site's 365-flight floor here, so there is no comparison to draw. The table below is the full picture.
| Airline | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| Republic Airwaysthin sample | 26 | 92.3% | 44 min | 0.00% | A+ |
| United Airlines (this page) | 1,773 | 74.0% | 94 min | 1.75% | C |
| American Airlines | 2,923 | 73.2% | 98 min | 3.90% | C− |
| Frontier Airlinesthin sample | 189 | 58.6% | 137 min | 4.23% | D− |
Flight by flight
United flight numbers on PHL to ORD
Departure window
When United runs best on this route
Departure time matters more here than the choice of carrier. The gap between the best and worst window is 32 points, against half a point between the best and worst carrier. Each bar is the on-time rate for flights scheduled inside that window.
- 5am–8am342 flights87.2%
- 8am–11am402 flights84.5%
- 11am–2pm407 flights81.3%
- 2pm–5pm3 flights—
- 5pm–8pm589 flights54.8%
- 8pm–5am30 flights—
Scale runs 45% to 95%. Rows with fewer than 30 flights show a dash.
The 5pm–8pm window is where this operation falls apart: 54.8% on time, against 87.2% 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 589 flights scheduled in it.
Across the year
United on PHL to ORD through the year
December is the weak month at 60.0% on time, against 83.0% 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. June was the busiest month here, with 197 flights.
Across the week, Tuesday is the strongest day at 80.9% on time and Sunday the weakest at 69.1%. 12 points is a smaller lever than departure hour, but it is free.
Delay causes
Why United runs late on this route
One category carries most of the weight here. National Airspace System accounts for 58% of the 42,000 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.
- 58%National Airspace System
- 21%Late-arriving aircraft
- 19%Carrier
- 2%Extreme weather
58% 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 25,000 minutes out of 42,000, against a national NAS share of 21%. The split is drawn from 42,485 reported delay minutes.
Cancellations sit at 1.75% against a national 1.81%, which is ordinary. Diversions add another 0.45%.
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. 9.7% 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.
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. 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 runs 72.2% on time across 1,776 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 1,773 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 United on PHL to ORD
Put together: the calendar is the biggest lever here, not the carrier or the hour. February runs 83.0% on time and December 60.0%, a swing of 23 points. If the dates move at all, move them out of December before you think about anything else. 1,734 completed flights over 12 months sit behind that.
Related
Where to go next
- PHL to ORD, every carrier
- United on ORD to PHL, the return leg
- American Airlines on PHL to ORD73.2%
- Frontier Airlines on PHL to ORD58.6%
- United Airlines network-wide record
- Philadelphia International (PHL) delay statistics
- Chicago O'Hare International (ORD) delay statistics
- The best time of day to fly, according to 7.04 million flight records
- How often a connection fails at the major US hubs
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.