Carrier route record
F9IAH→ORD
Frontier Airlines · Houston to Chicago
- Flights
- 248
- Period
- July 2025 to June 2026
- Share of route
- 4%
- Carriers
- 8
Historical statistics for July 2025 to June 2026, not live status. For today’s flights, check with Frontier Airlines.
Frontier on IAH to ORD draws a D. Roughly one flight in three arrives at least 15 minutes late, and the typical late arrival is about 2.2 hours behind schedule. Build slack into anything you connect to. That rests on 248 flights. The strongest carrier on the route with a full sample, United Airlines, flew 4,007 at 78.2% on time.
The national on-time rate over the same period is 77.6%, so Frontier on IAH to ORD runs 16 points behind the country as a whole. Across a thousand flights that is about 158 extra late arrivals.
Key figures
On time
61.8%
Arrivals under 15 minutes late, of 241 completed flights
Avg delay
130 min
Across delayed arrivals only, not all flights
Cancelled
2.82%
National rate is 1.81%
Whole route
74.8%
Every carrier on IAH to ORD, 6,080 flights
These figures cover 248 flights between July 2025 and June 2026. Beyond the headline rate, 20.7% 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
Frontier against every carrier on IAH to ORD
Frontier flew 248 of the 6,080 flights on IAH to ORD, about 4% of it. Its 61.8% on time is 13 points worse than the route as a whole, which runs 74.8%. Ranked by on-time rate it is number six of eight carriers on the route, where the range runs from United at 78.2% to PSA at 50.0%. Five of those carriers flew fewer than 365 flights here, so treat their positions as rough.
The choice of carrier is not cosmetic here. United Airlines arrives on time 78.2% of the time; American Airlines manages 67.1%. Sample sizes sit next to every figure, because a two-point gap across 798 flights means less than a ten-point one.
| Airline | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| United Airlines | 4,007 | 78.2% | 70 min | 0.60% | B+ |
| Envoy Airthin sample | 359 | 72.8% | 62 min | 1.11% | C |
| Republic Airwaysthin sample | 357 | 71.7% | 80 min | 3.64% | C− |
| American Airlines | 798 | 67.1% | 122 min | 3.51% | C− |
| Spirit Airlinesthin sample | 305 | 66.0% | 70 min | 4.59% | C− |
| Frontier Airlines (this page)thin sample | 248 | 61.8% | 130 min | 2.82% | D |
| SkyWest Airlinesthin sample | 2 | 50.0% | 38 min | 0.00% | F+ |
| PSA Airlinesthin sample | 4 | 50.0% | 156 min | 0.00% | F+ |
American Airlines cancels 3.5% 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.
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 28 points, against 11 points between the best and worst carrier. Each bar is the on-time rate for flights scheduled inside that window.
- 5am–8am3 flights—
- 8am–11am56 flights54.5%
- 11am–2pm32 flights75.0%
- 2pm–5pm6 flights—
- 5pm–8pm33 flights46.9%
- 8pm–5am118 flights65.5%
Scale runs 40% to 80%. Rows with fewer than 30 flights show a dash.
The 5pm–8pm window is where this operation falls apart: 46.9% on time, against 75.0% for the 11am–2pm 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 8pm–5am window is the busiest, with 118 flights scheduled in it.
Across the year
Frontier on IAH to ORD through the year
- Jul–Sep 202551 flights56.0%
- Oct–Dec 202560 flights61.4%
- Jan–Mar 202649 flights62.5%
- Apr–Jun 202688 flights65.1%
Scale runs 50% 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 61.8% on time across 248 flights.
Quarter by quarter Frontier on IAH to ORD held fairly steady: 56.0% in Jul–Sep 2025, 61.4% in Oct–Dec 2025, 62.5% in Jan–Mar 2026 and 65.1% in Apr–Jun 2026. A spread of 9 points is about what a sample of this size moves on its own, so the annual figure is a fair summary.
Across the week, Thursday is the strongest day at 68.9% on time and Sunday the weakest at 54.0%. 15 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 66% of the 12,000 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.
- 66%Late-arriving aircraft
- 18%National Airspace System
- 14%Carrier
- 1%Extreme weather
66% 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 12,000 reported delay minutes here, that single category outweighs weather by 45 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 11,952 reported delay minutes.
Cancellations run at 2.82%, against 1.81% nationally. That is roughly one flight in 40 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. 20.7% 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 925 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 76.0% on time across 249 flights, 14 points above 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 14 points of difference.
One caution: this is a thin sample. 248 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 IAH to ORD
Put together: the delay figures matter less here than the 2.82% cancellation rate. A late arrival costs you about 2.2 hours; a cancelled flight costs you the day. Book the 11am–2pm departure so there is still a schedule behind you if it goes wrong, and treat a same-day connection as optimistic. 241 completed flights over 12 months sit behind that.
Related
Where to go next
- IAH to ORD, every carrier
- Frontier on ORD to IAH, the return leg
- United Airlines on IAH to ORD78.2%
- Envoy Air on IAH to ORD72.8%
- Republic Airways on IAH to ORD71.7%
- American Airlines on IAH to ORD67.1%
- Spirit Airlines on IAH to ORD66.0%
- Frontier Airlines network-wide record
- George Bush Intercontinental (IAH) 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.