Route reliability record

ATL→FLL

Atlanta to Fort Lauderdale

Flights: 7,189
Period: July 2025 to June 2026
Distance: 581 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, 7 points worse than the national rate of 77.6%. The late ones land about an hour behind schedule. That rests on 7,189 flights, of which Delta Air Lines flew 4,272 at 73.5% on time.

Delta Air Lines is the most reliable of the four carriers covered here at 73.5% on time across 4,272 flights.

On time

70.7%

Arrivals under 15 minutes late, of 7,021 completed flights

Avg delay

64 min

Across delayed arrivals only, not all flights

Cancelled

2.14%

National rate is 1.81%

Best carrier

Delta

73.5% on time across 4,272 flights

These figures cover 7,189 flights between July 2025 and June 2026. Beyond the headline rate, 10.8% 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 ATL to FLL

The choice of carrier is not cosmetic here. Delta Air Lines arrives on time 73.5% of the time; Frontier Airlines manages 64.2%. Sample sizes sit next to every figure, because a two-point gap across 928 flights means less than a ten-point one.

On-time performance by carrier on ATL to FLL
Airline	Flights	On time	Avg delay	Cancelled	Grade
Southwest Airlinesthin sample	1	100.0%	—	0.00%	A+
Delta Air Lines	4,272	73.5%	55 min	1.57%	C
JetBlue Airways	647	70.2%	80 min	2.47%	C
Spirit Airlines	1,341	66.0%	69 min	3.65%	C−
Frontier Airlines	928	64.2%	80 min	2.37%	D

Spirit Airlines cancels 3.6% 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 24 points, against 9 points between the best and worst carrier. Each bar is the on-time rate for flights scheduled inside that window.

5am–8am906 flights84.6%
8am–11am1,528 flights78.5%
11am–2pm1,055 flights70.5%
2pm–5pm1,367 flights65.7%
5pm–8pm940 flights60.7%
8pm–5am1,393 flights64.8%

Scale runs 50% to 90%. Rows with fewer than 30 flights show a dash.

The 5pm–8pm window is where this operation falls apart: 60.7% on time, against 84.6% 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 1,528 flights scheduled in it.

Across the year

When delays peak on this route

This route's year swings by 28 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 781 flights.

Across the week, Wednesday is the strongest day at 79.4% on time and Sunday the weakest at 60.5%. 19 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 132,000 reported delay minutes.

Carrier
37%
Late-arriving aircraft
34%
National Airspace System
25%
Extreme weather
4%
Security
0%

34% 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 132,000 reported delay minutes here, that single category outweighs weather by 8 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 132,404 reported delay minutes.

The largest share of delay minutes, 37%, falls under carrier control: crew scheduling, maintenance, fuelling, baggage. Unlike weather, that is a management outcome, and it is the category where the gap between two carriers on the same schedule is genuinely earned. It accounts for 49,000 of the 132,000 delay minutes reported here.

Cancellations sit at 2.14% against a national 1.81%, which is ordinary. Diversions add another 0.19%.

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. 10.8% 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 581 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 71.8% on time across 7,185 flights, within about 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 7,189 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 56.6%, a swing of 28 points. If the dates move at all, move them out of March before you think about anything else. 7,021 completed flights over 12 months sit behind that.

Common questions

ATL to FLL questions

How often is ATL to FLL delayed?

Roughly 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 29.3% of the 7,189 flights in this analysis, against 22.4% nationally. Delayed flights are late by about an hour on average.

Which airline is most reliable on ATL to FLL?

Delta Air Lines leads at 73.5% on time across 4,272 flights. Frontier Airlines is at the other end on 64.2%, a gap of 9 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 ATL to FLL?

The 5am–8am departure window is the strongest at 84.6% on time. The 5pm–8pm window is the weakest at 60.7%, 24 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 ATL to FLL?

March is the weakest month at 56.6% on time, compared with 84.9% in September. Across the year that is 28 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. ATL to FLL and FLL to ATL 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