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DelayAtlas

Route reliability record

ATLFLL

Atlanta to Fort Lauderdale

Flights
7,174
Period
June 2025 to May 2026
Distance
581 mi
Carriers
5
CGRADE

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 77.4%. The late ones land about an hour behind schedule. That rests on 7,174 flights, of which Delta Air Lines flew 4,256 at 71.3% on time.

Delta Air Lines is the most reliable of the four carriers covered here at 71.3% on time across 4,256 flights.

Key figures

On time

68.9%

Arrivals under 15 minutes late, of 7,005 completed flights

Avg delay

65 min

Across delayed arrivals only, not all flights

Cancelled

2.16%

National rate is 1.80%

Best carrier

Delta

71.3% on time across 4,256 flights

These figures cover 7,174 flights between June 2025 and May 2026. Beyond the headline rate, 11.8% 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 71.3% of the time; Frontier Airlines manages 61.6%. Sample sizes sit next to every figure, because a two-point gap across 891 flights means less than a ten-point one.

On-time performance by carrier on ATL to FLL
AirlineFlightsOn timeAvg delayCancelledGrade
Southwest Airlinesthin sample1100.0%0.00%A+
Delta Air Lines4,25671.3%57 min1.55%C
JetBlue Airways55770.4%81 min2.87%C
Spirit Airlines1,46965.4%69 min3.47%C−
Frontier Airlines89161.6%81 min2.47%D

Spirit Airlines cancels 3.5% 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 24 points, against 10 points between the best and worst carrier. Each bar is the on-time rate for flights scheduled inside that window.

  • 5am–8am888 flights83.7%
  • 8am–11am1,554 flights77.4%
  • 11am–2pm982 flights68.6%
  • 2pm–5pm1,398 flights63.2%
  • 5pm–8pm958 flights59.3%
  • 8pm–5am1,394 flights62.7%

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

The 5pm–8pm window is where this operation falls apart: 59.3% on time, against 83.7% 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.

Across the year

When delays peak on this route

This route's year swings by 31 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.

On-time rate by calendar month67J69F57M74A74M54J61J72A85S79O76N65D
Darker means more delays. Figures are on-time percentages.September best, June worst

June is the worst month at 54.4% on time, 31 points below September, the best at 84.9%. Summer afternoon convection and peak-season schedules land on the same weeks every year, so this is a pattern you can book around rather than a run of bad luck.

Across the week, Wednesday is the strongest day at 76.7% on time and Sunday the weakest at 57.8%. 19 points is a smaller lever than departure hour, but it is free.

On-time rate by day of the week66.9Mon76.5Tue76.7Wed70.0Thu68.8Fri66.3Sat57.8Sun
Monday: 66.9 percent on time. Tuesday: 76.5 percent on time. Wednesday: 76.7 percent on time. Thursday: 70.0 percent on time. Friday: 68.8 percent on time. Saturday: 66.3 percent on time. Sunday: 57.8 percent on time

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 142,000 reported delay minutes.

  • Carrier
    36%
  • Late-arriving aircraft
    34%
  • National Airspace System
    25%
  • Extreme weather
    5%
  • Security
    0%

The largest share of delay minutes, 36%, 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 51,000 of the 142,000 delay minutes reported here.

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 83.7% on time here.

Cancellations sit at 2.16% against a national 1.80%, which is ordinary. Diversions add another 0.20%.

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. 11.8% of arrivals land a full hour or more behind schedule, against 8.2% 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 70.9% on time across 7,168 flights, within 2 points 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 7,174 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 June 54.4%, a swing of 31 points. If the dates move at all, move them out of June before you think about anything else.

Common questions

ATL to FLL questions

How often is ATL to FLL 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 31.1% of the 7,174 flights in this analysis, against 22.6% 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 71.3% on time across 4,256 flights. Frontier Airlines is at the other end on 61.6%, a gap of 10 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 83.7% on time. The 5pm–8pm window is the weakest at 59.3%, 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 June delays on ATL to FLL?

June is the weakest month at 54.4% on time, compared with 84.9% in September. Across the year that is 31 points between the best and worst months. Moving flexible dates out of that month is one of the few things that reliably helps.

Related

Where to go next

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