Route reliability record

ORD→FLL

Chicago to Fort Lauderdale

Flights: 3,424
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, 5 points worse than the national rate of 77.6%. The late ones land a little over an hour behind schedule. That rests on 3,424 flights, of which United Airlines flew 1,478 at 78.5% on time.

United Airlines is the most reliable of the three carriers covered here at 78.5% on time across 1,478 flights.

On time

72.8%

Arrivals under 15 minutes late, of 3,340 completed flights

Avg delay

78 min

Across delayed arrivals only, not all flights

Cancelled

2.10%

National rate is 1.81%

Best carrier

United

78.5% on time across 1,478 flights

These figures cover 3,424 flights between July 2025 and June 2026. Beyond the headline rate, 10.7% 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 FLL

The choice of carrier is not cosmetic here. United Airlines arrives on time 78.5% of the time; Spirit Airlines manages 65.3%. Sample sizes sit next to every figure, because a two-point gap across 916 flights means less than a ten-point one.

On-time performance by carrier on ORD to FLL
Airline	Flights	On time	Avg delay	Cancelled	Grade
United Airlines	1,478	78.5%	67 min	0.81%	B+
American Airlines	846	71.7%	82 min	1.54%	C
Frontier Airlinesthin sample	151	67.6%	86 min	3.31%	C−
Southwest Airlinesthin sample	33	65.6%	52 min	3.03%	C−
Spirit Airlines	916	65.3%	85 min	4.48%	C−

Spirit Airlines cancels 4.5% 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

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 29 points, against 13 points between the best and worst carrier. Each bar is the on-time rate for flights scheduled inside that window.

5am–8am1,045 flights82.0%
8am–11am762 flights74.2%
11am–2pm558 flights73.0%
2pm–5pm455 flights65.4%
5pm–8pm542 flights61.1%
8pm–5am62 flights53.4%

Scale runs 45% to 85%. Rows with fewer than 30 flights show a dash.

The 8pm–5am window is where this operation falls apart: 53.4% on time, against 82.0% 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 5am–8am window is the busiest, with 1,045 flights scheduled in it.

Across the year

When delays peak on this route

This route's year swings by 26 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.August best, March worst

Delays peak in March, when the on-time rate falls to 57.3%. August is the strongest month at 83.4%. Moving a flexible trip across that boundary buys 26 points. March was the busiest month here, with 440 flights.

Across the week, Tuesday is the strongest day at 79.3% on time and Sunday the weakest at 65.7%. 14 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 71,000 reported delay minutes.

Late-arriving aircraft
37%
National Airspace System
30%
Carrier
26%
Extreme weather
7%
Security
0%

37% 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 71,000 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 70,529 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 82.0% on time here.

Cancellations sit at 2.10% against a national 1.81%, which is ordinary. Diversions add another 0.35%.

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. 10.7% 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 1,182 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 69.1% on time across 3,422 flights, 4 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 4 points of difference.

The sample behind these figures is 3,424 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. August runs 83.4% on time and March 57.3%, a swing of 26 points. If the dates move at all, move them out of March before you think about anything else. 3,340 completed flights over 12 months sit behind that.

Common questions

ORD to FLL questions

How often is ORD to FLL delayed?

Roughly 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 27.2% of the 3,424 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 FLL?

United Airlines leads at 78.5% on time across 1,478 flights. Spirit Airlines is at the other end on 65.3%, 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 ORD to FLL?

The 5am–8am departure window is the strongest at 82.0% on time. The 8pm–5am window is the weakest at 53.4%, 29 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 FLL?

March is the weakest month at 57.3% on time, compared with 83.4% in August. Across the year that is 26 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 FLL and FLL 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