Carrier route record
NKORD→MIA
Spirit Airlines · Chicago to Miami
- Flights
- 348
- Period
- July 2025 to June 2026
- Share of route
- 8%
- Carriers
- 4
Historical statistics for July 2025 to June 2026, not live status. For today’s flights, check with Spirit Airlines.
Spirit on ORD to MIA draws a D−. Roughly 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 348 flights. The strongest carrier on the route with a full sample, American Airlines, flew 3,015 at 75.6% on time.
The national on-time rate over the same period is 77.6%, so Spirit on ORD to MIA runs 16 points behind the country as a whole. Across a thousand flights that is about 163 extra late arrivals.
Key figures
On time
61.3%
Arrivals under 15 minutes late, of 326 completed flights
Avg delay
70 min
Across delayed arrivals only, not all flights
Cancelled
6.32%
National rate is 1.81%
Whole route
74.0%
Every carrier on ORD to MIA, 4,450 flights
These figures cover 348 flights between July 2025 and June 2026. Beyond the headline rate, 14.4% 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 ORD to MIA
Spirit flew 348 of the 4,450 flights on ORD to MIA, about 8% of it. Its 61.3% on time is 13 points worse than the route as a whole, which runs 74.0%. Ranked by on-time rate it is last of four carriers on the route, where the range runs from American at 75.6% to Spirit at 61.3%. One of those carriers flew fewer than 365 flights here, so treat their positions as rough.
The two carriers here are closely matched: 2 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 |
|---|---|---|---|---|---|
| American Airlines | 3,015 | 75.6% | 72 min | 1.92% | B |
| United Airlines | 1,041 | 73.7% | 61 min | 0.58% | C+ |
| Frontier Airlinesthin sample | 46 | 64.4% | 120 min | 2.17% | D |
| Spirit Airlines (this page)thin sample | 348 | 61.3% | 70 min | 6.32% | D− |
No carrier stands out. American tops the table at 75.6%, 2 points clear of the bottom, which is inside the range this kind of sample moves year to year.
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 34 points, against 2 points between the best and worst carrier. Each bar is the on-time rate for flights scheduled inside that window.
- 5am–8am3 flights—
- 8am–11am168 flights74.4%
- 11am–2pm66 flights56.9%
- 2pm–5pm—
- 5pm–8pm111 flights40.4%
- 8pm–5am—
Scale runs 30% to 80%. Rows with fewer than 30 flights show a dash.
The 5pm–8pm window is where this operation falls apart: 40.4% on time, against 74.4% 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 8am–11am window is the busiest, with 168 flights scheduled in it.
Across the year
Spirit on ORD to MIA through the year
- Jul–Sep 202591 flights83.3%
- Oct–Dec 202573 flights72.1%
- Jan–Mar 2026145 flights43.8%
- Apr–Jun 202639 flights50.0%
Scale runs 35% to 90%. 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 61.3% on time across 348 flights.
Spirit on ORD to MIA did not run the same all year. Its best quarter was Jul–Sep 2025 at 83.3% on time and its weakest Jan–Mar 2026 at 43.8%, a swing of 40 points on roughly 87 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 67.3% on time and Sunday the weakest at 52.1%. 15 points is a smaller lever than departure hour, but it is free.
Delay causes
Why Spirit runs late on this route
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 8,780 reported delay minutes.
- 42%National Airspace System
- 33%Carrier
- 21%Late-arriving aircraft
- 4%Extreme weather
- 0%Security
42% 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 3,677 minutes out of 8,780, against a national NAS share of 21%. The split is drawn from 8,780 reported delay minutes.
Cancellations run at 6.32%, against 1.81% nationally. That is about one flight in fifteen 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. 14.4% 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 1,197 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 63.2% on time across 346 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. 348 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 ORD to MIA
Put together: the delay figures matter less here than the 6.32% 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. 326 completed flights over 12 months sit behind that.
Related
Where to go next
- ORD to MIA, every carrier
- Spirit on MIA to ORD, the return leg
- American Airlines on ORD to MIA75.6%
- United Airlines on ORD to MIA73.7%
- Spirit Airlines network-wide record
- Chicago O'Hare International (ORD) delay statistics
- Miami International (MIA) delay statistics
- The US routes with the most cancellations
- What a cancellation rate actually tells you (and what it hides)
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.