Carrier route record

NKSJU→ORD

Spirit Airlines · San Juan to Chicago

Flights: 294
Period: July 2025 to June 2026
Share of route: 21%
Carriers: 4

Historical statistics for July 2025 to June 2026, not live status. For today’s flights, check with Spirit Airlines.

Spirit on SJU to ORD lands a B−, 3 points better than the national rate of 77.6%. About one flight in five arrives 15 minutes late or worse, and those flights are late by a little over an hour on average. That is a workable record, not a spotless one. That rests on 294 flights. The strongest carrier on the route with a full sample, United Airlines, flew 665 at 82.1% on time.

The US average over the same twelve months is 77.6%, so there is little to separate Spirit on SJU to ORD from the country as a whole. The variation that matters here is internal: which carrier, and what time of day.

On time

80.3%

Arrivals under 15 minutes late, of 274 completed flights

Avg delay

80 min

Across delayed arrivals only, not all flights

Cancelled

6.12%

National rate is 1.81%

Whole route

79.5%

Every carrier on SJU to ORD, 1,397 flights

These figures cover 294 flights between July 2025 and June 2026. Beyond the headline rate, 8.0% 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 SJU to ORD

Spirit flew 294 of the 1,397 flights on SJU to ORD, about 21% of it. Its 80.3% on time is about level with the route as a whole at 79.5%. Ranked by on-time rate it is number three of four carriers on the route, where the range runs from Frontier at 90.9% to American at 74.5%. One 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 82.1% of the time; American Airlines manages 74.5%. Sample sizes sit next to every figure, because a two-point gap across 426 flights means less than a ten-point one.

On-time performance by carrier on SJU to ORD
Airline	Flights	On time	Avg delay	Cancelled	Grade
Frontier Airlinesthin sample	12	90.9%	16 min	0.00%	A+
United Airlines	665	82.1%	39 min	0.60%	B+
Spirit Airlines (this page)thin sample	294	80.3%	80 min	6.12%	B−
American Airlines	426	74.5%	99 min	1.88%	C

United leads American by 8 points. Real, but small enough that a better departure time on the weaker carrier can outweigh 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 32 points, against 8 points between the best and worst carrier. Each bar is the on-time rate for flights scheduled inside that window.

5am–8am34 flights100.0%
8am–11am13 flights—
11am–2pm108 flights75.7%
2pm–5pm35 flights67.6%
5pm–8pm44 flights90.9%
8pm–5am60 flights69.6%

Scale runs 60% to 100%. Rows with fewer than 30 flights show a dash.

Book the early departure. Flights leaving between 5am–8am arrive on time 100.0% of the time, against 67.6% for the afternoon window. That is 32 points of difference for no extra money, and it comes from the same aircraft having had no earlier flight to fall behind on. The 11am–2pm window is the busiest, with 108 flights scheduled in it.

Across the year

Spirit on SJU to ORD through the year

Jul–Sep 202586 flights90.6%
Oct–Dec 202557 flights72.7%
Jan–Mar 2026107 flights74.2%
Apr–Jun 202644 flights82.9%

Scale runs 65% 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 80.3% on time across 294 flights.

Spirit on SJU to ORD did not run the same all year. Its best quarter was Jul–Sep 2025 at 90.6% on time and its weakest Oct–Dec 2025 at 72.7%, a swing of 18 points on roughly 74 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, Sunday is the strongest day at 88.6% on time and Tuesday the weakest at 70.6%. 18 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 4,309 reported delay minutes.

National Airspace System
34%
Late-arriving aircraft
33%
Carrier
30%
Extreme weather
3%

34% 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 1,475 minutes out of 4,309, against a national NAS share of 21%. The split is drawn from 4,309 reported delay minutes.

The practical consequence: the 5am–8am departure is the one that starts clean. Its aircraft has no earlier leg to be late from, which is exactly why that window shows 100.0% on time here.

Cancellations run at 6.12%, against 1.81% nationally. That is roughly 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

8.0% of arrivals land an hour or more late, close to the national 8.1%. That is the figure that decides a connection, and it says a 60 to 75 minute layover is reasonable here while anything under 45 minutes is a bet. Most delays on this route last a little over an hour, which a normal layover absorbs.

At 2,072 miles this is transcontinental flying, and long routes get a quiet structural advantage. Scheduled block time on a flight this length carries more padding in absolute minutes, so a twenty-minute late departure often still becomes an on-time arrival. Read the on-time rate here as slightly flattering next to a short-haul route with the same operational quality.

The return leg is a different operation and performs like one: it runs 62.7% on time across 297 flights, 18 points below 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 18 points of difference.

One caution: this is a thin sample. 294 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 SJU to ORD

Put together: the delay figures matter less here than the 6.12% cancellation rate. A late arrival costs you a little over an hour; a cancelled flight costs you the day. Book the 5am–8am departure so there is still a schedule behind you if it goes wrong, and treat a same-day connection as optimistic. 274 completed flights over 12 months sit behind that.

Where to go next

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.

Key figures