Route reliability record

ORD→RSW

Chicago to Fort Myers

Flights: 3,239
Period: July 2025 to June 2026
Distance: 1,120 mi
Carriers: 5

This route lands a B, 2 points worse than the national rate of 77.6%. About one flight in four arrive 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 3,239 flights, of which United Airlines flew 1,612 at 81.8% on time.

United Airlines is the most reliable of the three carriers covered here at 81.8% on time across 1,612 flights.

On time

76.1%

Arrivals under 15 minutes late, of 3,176 completed flights

Avg delay

70 min

Across delayed arrivals only, not all flights

Cancelled

1.64%

National rate is 1.81%

Best carrier

United

81.8% on time across 1,612 flights

These figures cover 3,239 flights between July 2025 and June 2026. Beyond the headline rate, 9.7% 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

Which airline is most reliable on ORD to RSW

The choice of carrier is not cosmetic here. United Airlines arrives on time 81.8% of the time; Spirit Airlines manages 60.8%. Sample sizes sit next to every figure, because a two-point gap across 372 flights means less than a ten-point one.

On-time performance by carrier on ORD to RSW
Airline	Flights	On time	Avg delay	Cancelled	Grade
United Airlines	1,612	81.8%	67 min	0.50%	B+
Southwest Airlinesthin sample	103	78.0%	50 min	2.91%	B
Frontier Airlinesthin sample	36	77.1%	75 min	2.78%	B
American Airlines	1,116	72.4%	70 min	1.88%	C
Spirit Airlines	372	60.8%	79 min	5.38%	D−

Spirit Airlines cancels 5.4% 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

The best time of day to leave

Departure time matters more here than the choice of carrier. The gap between the best and worst window is 30 points, against 21 points between the best and worst carrier. Each bar is the on-time rate for flights scheduled inside that window.

5am–8am830 flights87.9%
8am–11am845 flights80.7%
11am–2pm555 flights72.4%
2pm–5pm452 flights71.8%
5pm–8pm478 flights57.9%
8pm–5am79 flights60.8%

Scale runs 50% to 95%. Rows with fewer than 30 flights show a dash.

The 5pm–8pm window is where this operation falls apart: 57.9% on time, against 87.9% for the 5am–8am 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 845 flights scheduled in it.

Across the year

When delays peak on this route

This route's year swings by 24 points from best month to worst, which is wide. An annual average tells you very little about the week you are actually flying, so read the strip rather than the headline if your dates are fixed.

Darker means more delays. Figures are on-time percentages.September best, March worst

September is the best month on the calendar at 91.7% on time. Shoulder season thins the schedule and takes the summer weather with it, and the operation gets its margin back. March was the busiest month here, with 469 flights.

Across the week, Tuesday is the strongest day at 82.4% on time and Sunday the weakest at 71.3%. 11 points is a smaller lever than departure hour, but it is free.

Delay causes

Why this route gets delayed

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 53,000 reported delay minutes.

Late-arriving aircraft
41%
National Airspace System
29%
Carrier
24%
Extreme weather
6%
Security
0%

41% 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 53,000 reported delay minutes here, that single category outweighs weather by 7 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 53,171 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 87.9% on time here.

Cancellations sit at 1.64% against a national 1.81%, which is ordinary. Diversions add another 0.31%.

Connections and stage length

What a delay here actually costs

For anyone connecting, the number to weigh is not the on-time rate but the tail behind it. 9.7% 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 1,120 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 76.5% on time across 3,232 flights, within half a point of this direction. The two legs are scored separately because they usually differ; on this city pair they happen not to.

The sample behind these figures is 3,239 flights, enough that the headline rate is stable to within roughly a point. The hour-block and month splits divide that further, so read the thinner bars with more caution than the headline.

What to do with this

Booking this route

Put together: the calendar is the biggest lever here, not the carrier or the hour. September runs 91.7% on time and March 67.4%, a swing of 24 points. If the dates move at all, move them out of March before you think about anything else. 3,176 completed flights over 12 months sit behind that.

Common questions

ORD to RSW questions

How often is ORD to RSW delayed?

About one flight in four arrive at least 15 minutes late, which is the Department of Transportation's definition of a delayed arrival. That works out to 23.9% of the 3,239 flights in this analysis, against 22.4% nationally. Delayed flights are late by a little over an hour on average.

Which airline is most reliable on ORD to RSW?

United Airlines leads at 81.8% on time across 1,612 flights. Spirit Airlines is at the other end on 60.8%, a gap of 21 points. Sample size matters as much as the percentage: a rate built from a few hundred flights moves around far more than one built from ten thousand.

What time of day has the fewest delays on ORD to RSW?

The 5am–8am departure window is the strongest at 87.9% on time. The 5pm–8pm window is the weakest at 57.9%, 30 points behind. Later departures inherit delays from earlier flights the same aircraft has already flown, which is why the curve slopes the way it does.

How bad are March delays on ORD to RSW?

March is the weakest month at 67.4% on time, compared with 91.7% in September. Across the year that is 24 points between the best and worst months. Moving flexible dates out of that month is one of the few things that reliably helps.

Where to go next

Direction matters. ORD to RSW and RSW to ORD are scored separately because they are separate operations, with different departure banks and different aircraft. Compare the return leg.

Source: US DOT Bureau of Transportation Statistics, on-time performance data, July 2025 to June 2026. Updated monthly. How this data is collected.

Key figures