Carrier route record
NKIAH→ORD
Spirit Airlines · Houston to Chicago
- Flights
- 305
- Period
- July 2025 to June 2026
- Share of route
- 5%
- Carriers
- 8
Historical statistics for July 2025 to June 2026, not live status. For today’s flights, check with Spirit Airlines.
Spirit on IAH to ORD draws a C−. About one flight in three arrives at least 15 minutes late, and the typical late arrival is a little over an hour behind schedule. Build slack into anything you connect to. That rests on 305 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 Spirit on IAH to ORD runs 12 points behind the country as a whole. Across a thousand flights that is about 116 extra late arrivals.
Key figures
On time
66.0%
Arrivals under 15 minutes late, of 291 completed flights
Avg delay
70 min
Across delayed arrivals only, not all flights
Cancelled
4.59%
National rate is 1.81%
Whole route
74.8%
Every carrier on IAH to ORD, 6,080 flights
These figures cover 305 flights between July 2025 and June 2026. Beyond the headline rate, 14.1% 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
Spirit against every carrier on IAH to ORD
Spirit flew 305 of the 6,080 flights on IAH to ORD, about 5% of it. Its 66.0% on time is 9 points worse than the route as a whole, which runs 74.8%. Ranked by on-time rate it is number five 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 Airlines (this page)thin sample | 305 | 66.0% | 70 min | 4.59% | C− |
| Frontier Airlinesthin 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 Spirit runs best on this route
Departure time matters more here than the choice of carrier. The gap between the best and worst window is 27 points, against 11 points between the best and worst carrier. Each bar is the on-time rate for flights scheduled inside that window.
- 5am–8am59 flights74.5%
- 8am–11am31 flights83.9%
- 11am–2pm91 flights57.0%
- 2pm–5pm16 flights—
- 5pm–8pm102 flights68.0%
- 8pm–5am6 flights—
Scale runs 50% to 90%. Rows with fewer than 30 flights show a dash.
The weak window here is the middle of the day, not the evening: 11am–2pm runs 57.0% on time against 83.9% for 8am–11am. That shape usually means a departure bank rather than an accumulating delay, so the recovery later in the afternoon is real rather than noise. The 5pm–8pm window is the busiest, with 102 flights scheduled in it.
Across the year
Spirit on IAH to ORD through the year
- Jul–Sep 2025108 flights87.6%
- Oct–Dec 202586 flights56.8%
- Jan–Mar 202687 flights57.8%
- Apr–Jun 202624 flights—
Scale runs 50% to 95%. 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 66.0% on time across 305 flights.
Spirit on IAH to ORD did not run the same all year. Its best quarter was Jul–Sep 2025 at 87.6% on time and its weakest Oct–Dec 2025 at 56.8%, a swing of 31 points on roughly 102 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, Wednesday is the strongest day at 80.0% on time and Thursday the weakest at 57.8%. 22 points is a smaller lever than departure hour, but it is free.
Delay causes
Why Spirit runs late on this route
One category carries most of the weight here. National Airspace System accounts for 46% of the 6,955 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%National Airspace System
- 27%Late-arriving aircraft
- 26%Carrier
- 1%Security
46% 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 3,195 minutes out of 6,955, against a national NAS share of 21%. The split is drawn from 6,955 reported delay minutes.
Cancellations run at 4.59%, against 1.81% nationally. That is roughly one flight in twenty 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. 14.1% 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 runs 63.1% on time across 307 flights, within 3 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. 305 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 Spirit on IAH to ORD
Put together: the delay figures matter less here than the 4.59% cancellation rate. A late arrival costs you a little over an hour; 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. 291 completed flights over 12 months sit behind that.
Related
Where to go next
- IAH to ORD, every carrier
- Spirit 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%
- Frontier Airlines on IAH to ORD61.8%
- Spirit Airlines network-wide record
- George Bush Intercontinental (IAH) delay statistics
- Chicago O'Hare International (ORD) delay statistics
- The US routes with the most cancellations
- Same route, different airline: where the carrier you pick matters most
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.