Carrier route record
F9PHL→ORD
Frontier Airlines · Philadelphia to Chicago
- Flights
- 189
- Period
- July 2025 to June 2026
- Share of route
- 4%
- Carriers
- 4
Historical statistics for July 2025 to June 2026, not live status. For today’s flights, check with Frontier Airlines.
Frontier on PHL to ORD draws a D−. Roughly one flight in two arrives at least 15 minutes late, and the typical late arrival is about 2.3 hours behind schedule. Build slack into anything you connect to. That rests on 189 flights. The strongest carrier on the route with a full sample, United Airlines, flew 1,773 at 74.0% on time.
The national on-time rate over the same period is 77.6%, so Frontier on PHL to ORD runs 19 points behind the country as a whole. Across a thousand flights that is about 190 extra late arrivals.
Key figures
On time
58.6%
Arrivals under 15 minutes late, of 181 completed flights
Avg delay
137 min
Across delayed arrivals only, not all flights
Cancelled
4.23%
National rate is 1.81%
Whole route
73.0%
Every carrier on PHL to ORD, 4,911 flights
These figures cover 189 flights between July 2025 and June 2026. Beyond the headline rate, 24.3% 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
Frontier against every carrier on PHL to ORD
Frontier flew 189 of the 4,911 flights on PHL to ORD, about 4% of it. Its 58.6% on time is 14 points worse than the route as a whole, which runs 73.0%. Ranked by on-time rate it is last of four carriers on the route, where the range runs from Republic at 92.3% to Frontier at 58.6%. One of those carriers flew fewer than 365 flights here, so treat their positions as rough.
The two carriers here are closely matched: about 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 |
|---|---|---|---|---|---|
| Republic Airwaysthin sample | 26 | 92.3% | 44 min | 0.00% | A+ |
| United Airlines | 1,773 | 74.0% | 94 min | 1.75% | C |
| American Airlines | 2,923 | 73.2% | 98 min | 3.90% | C− |
| Frontier Airlines (this page)thin sample | 189 | 58.6% | 137 min | 4.23% | D− |
American Airlines cancels 3.9% 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.
Departure window
When Frontier runs best on this route
Departure time matters more here than the choice of carrier. The gap between the best and worst window is 24 points, against about a point between the best and worst carrier. Each bar is the on-time rate for flights scheduled inside that window.
- 5am–8am16 flights—
- 8am–11am45 flights75.0%
- 11am–2pm13 flights—
- 2pm–5pm22 flights—
- 5pm–8pm76 flights51.4%
- 8pm–5am17 flights—
Scale runs 45% to 80%. Rows with fewer than 30 flights show a dash.
The 5pm–8pm window is where this operation falls apart: 51.4% on time, against 75.0% for the 8am–11am 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 76 flights scheduled in it.
Across the year
Frontier on PHL to ORD through the year
- Jul–Sep 202551 flights51.0%
- Oct–Dec 202551 flights63.3%
- Jan–Mar 202630 flights—
- Apr–Jun 202657 flights61.8%
Scale runs 45% to 70%. Rows with fewer than 30 flights show a dash.
Monthly volumes are too low here to break the year into twelve reliable readings. What the twelve-month total says is 58.6% on time across 189 flights.
Frontier on PHL to ORD did not run the same all year. Its best quarter was Oct–Dec 2025 at 63.3% on time and its weakest Jul–Sep 2025 at 51.0%, a swing of 12 points on roughly 63 flights a quarter. The twelve-month rate averages over that, so if you are flying in a weak quarter the quarter's own figure is the better guide.
Across the week, Thursday is the strongest day at 64.7% on time and Monday the weakest at 54.5%. 10 points is a smaller lever than departure hour, but it is free.
Delay causes
Why Frontier runs late on this route
One category carries most of the weight here. Late-arriving aircraft accounts for 46% of the 10,000 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.
- 46%Late-arriving aircraft
- 45%National Airspace System
- 10%Carrier
46% 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 10,000 reported delay minutes here, that single category outweighs weather by 46 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 10,237 reported delay minutes.
45% 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 4,556 minutes out of 10,000, against a national NAS share of 21%.
Cancellations run at 4.23%, against 1.81% nationally. That is about one flight in 25 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 costs
For anyone connecting, the number to weigh is not the on-time rate but the tail behind it. 24.3% 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 60.4% on time across 189 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.
One caution: this is a thin sample. 189 flights over twelve months is enough to clear this site's floor but not enough to pin the rate down tightly, and a single bad week moves it by more than a point. Treat the grade as a rough reading.
What to do with this
Booking Frontier on PHL to ORD
Put together: the delay figures matter less here than the 4.23% cancellation rate. A late arrival costs you about 2.3 hours; a cancelled flight costs you the day. Book the 8am–11am departure so there is still a schedule behind you if it goes wrong, and treat a same-day connection as optimistic. 181 completed flights over 12 months sit behind that.
Related
Where to go next
- PHL to ORD, every carrier
- Frontier on ORD to PHL, the return leg
- United Airlines on PHL to ORD74.0%
- American Airlines on PHL to ORD73.2%
- Frontier Airlines network-wide record
- Philadelphia International (PHL) delay statistics
- Chicago O'Hare International (ORD) delay statistics
- The US routes with the most cancellations
- Why the first flight of the morning is statistically safest
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.