Route reliability record

FLL→ORD

Fort Lauderdale to Chicago

Flights: 3,422
Period: July 2025 to June 2026
Distance: 1,182 mi
Carriers: 5

This route sits in the middle of the pack with a C. About seven flights in ten arrive on time by the DOT's definition, 9 points worse than the national rate of 77.6%. The late ones land an hour and a half behind schedule. That rests on 3,422 flights, of which United Airlines flew 1,479 at 74.7% on time.

United Airlines is the most reliable of the three carriers covered here at 74.7% on time across 1,479 flights.

On time

69.1%

Arrivals under 15 minutes late, of 3,339 completed flights

Avg delay

88 min

Across delayed arrivals only, not all flights

Cancelled

1.75%

National rate is 1.81%

Best carrier

United

74.7% on time across 1,479 flights

These figures cover 3,422 flights between July 2025 and June 2026. Beyond the headline rate, 12.8% 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 FLL to ORD

The choice of carrier is not cosmetic here. United Airlines arrives on time 74.7% of the time; Spirit Airlines manages 61.3%. Sample sizes sit next to every figure, because a two-point gap across 913 flights means less than a ten-point one.

On-time performance by carrier on FLL to ORD
Airline	Flights	On time	Avg delay	Cancelled	Grade
United Airlines	1,479	74.7%	81 min	0.74%	C+
American Airlines	846	70.0%	103 min	1.54%	C
Spirit Airlines	913	61.3%	73 min	3.29%	D−
Frontier Airlinesthin sample	151	61.1%	148 min	3.31%	D−
Southwest Airlinesthin sample	33	38.7%	98 min	3.03%	F−

Spirit Airlines cancels 3.3% 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 33 points, against 13 points between the best and worst carrier. Each bar is the on-time rate for flights scheduled inside that window.

5am–8am527 flights85.9%
8am–11am466 flights81.2%
11am–2pm843 flights78.8%
2pm–5pm693 flights54.7%
5pm–8pm550 flights53.2%
8pm–5am343 flights56.4%

Scale runs 45% to 90%. Rows with fewer than 30 flights show a dash.

The 5pm–8pm window is where this operation falls apart: 53.2% on time, against 85.9% 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 11am–2pm window is the busiest, with 843 flights scheduled in it.

Across the year

When delays peak on this route

This route's year swings by 33 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 84.9% 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 440 flights.

Across the week, Tuesday is the strongest day at 73.9% on time and Sunday the weakest at 61.5%. 12 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 90,000 reported delay minutes.

Late-arriving aircraft
35%
National Airspace System
35%
Carrier
25%
Extreme weather
6%
Security
0%

35% 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 90,000 reported delay minutes here, that single category outweighs weather by 6 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 90,338 reported delay minutes.

35% 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 31,000 minutes out of 90,000, against a national NAS share of 21%.

Cancellations sit at 1.75% against a national 1.81%, which is ordinary. Diversions add another 0.67%.

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. 12.8% 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 1,182 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 72.8% on time across 3,424 flights, 4 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 4 points of difference.

The sample behind these figures is 3,422 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 84.9% on time and March 51.8%, a swing of 33 points. If the dates move at all, move them out of March before you think about anything else. 3,339 completed flights over 12 months sit behind that.

Common questions

FLL to ORD questions

How often is FLL to ORD delayed?

About one flight in three arrive at least 15 minutes late, which is the Department of Transportation's definition of a delayed arrival. That works out to 30.9% of the 3,422 flights in this analysis, against 22.4% nationally. Delayed flights are late by an hour and a half on average.

Which airline is most reliable on FLL to ORD?

United Airlines leads at 74.7% on time across 1,479 flights. Spirit Airlines is at the other end on 61.3%, a gap of 13 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 FLL to ORD?

The 5am–8am departure window is the strongest at 85.9% on time. The 5pm–8pm window is the weakest at 53.2%, 33 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 FLL to ORD?

March is the weakest month at 51.8% on time, compared with 84.9% in September. Across the year that is 33 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. FLL to ORD and ORD to FLL 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