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DelayAtlas

Route reliability record

MDWFLL

Chicago to Fort Lauderdale

Flights
1,127
Period
July 2025 to June 2026
Distance
1,167 mi
Carriers
1
CGRADE

This route sits in the middle of the pack with a C. Close to three flights in four arrive on time by the DOT's definition, 4 points worse than the national rate of 77.6%. The late ones land about an hour behind schedule. That rests on 1,127 MDW to FLL flights, with a median arrival 1 minute early.

Best time to fly MDW to FLL: a 5am–8am departure, ideally on a Wednesday. Flights in that window arrived on time 91.4% of the time and Wednesday flights 81.4%, against 74.0% for the route overall.

The US average over the same twelve months is 77.6%, so there is little to separate this route from the country as a whole. The variation that matters here is internal: which carrier, and what time of day.

Key figures

On time

74.0%

Arrivals under 15 minutes late, of 1,108 completed flights

Avg delay

57 min

Across delayed arrivals only, not all flights

Cancelled

1.51%

National rate is 1.81%

Best carrier

Southwest

74.0% on time across 1,127 flights

These figures cover 1,127 flights between July 2025 and June 2026. On-time means an arrival less than 15 minutes after the scheduled gate time, the same threshold the Department of Transportation uses in its own reports. Cancelled and diverted flights are excluded from the on-time rate and counted separately, which is why the cancellation column matters on its own.

Carrier by carrier

Which airline is most reliable on MDW to FLL

Only one carrier clears this site's 365-flight floor here, so there is no comparison to draw. The table below is the full picture.

On-time performance by carrier on MDW to FLL
AirlineFlightsOn timeAvg delayCancelledGrade
Southwest Airlines1,12774.0%57 min1.51%C

Best ways to make this trip

The most reliable ways to fly Chicago to Fort Lauderdale

Every airline on this route and on the routes between nearby airports, ranked by how often a scheduled flight actually operated and arrived on time. 4 of the top 5 use a different airport at one end.

Most reliable ways to fly from MDW to FLL
OptionAirlineSuccessOn timeCancelledBest departureMost punctual flight
1. ORDFLLChicago to Fort LauderdaleUnited Airlines77.9%78.5%0.81%5am–8am, TueUA 1421 07:00
2. ORDMIAChicago to MiamiAmerican Airlines74.1%75.6%1.92%5am–8am, TueAA 2984 05:00
3. ORDMIAChicago to MiamiUnited Airlines73.3%73.7%0.58%5am–8am, Tue
4. ORDPBIChicago to West Palm BeachUnited Airlines73.2%73.5%0.40%5am–8am, Tue
5. MDWFLLChicago to Fort LauderdaleSouthwest Airlines72.9%74.0%1.51%5am–8am, Wed

Success is the share of scheduled flights that operated and arrived less than 15 minutes late, so a cancelled flight counts against it. “(route)” means the best time comes from every carrier on the route rather than this airline alone.

Plan this trip by month, day and time

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 31 points, against half a point between the best and worst carrier. Each bar is the on-time rate for flights scheduled inside that window.

  • 5am–8am187 flights91.4%
  • 8am–11am218 flights80.3%
  • 11am–2pm179 flights75.0%
  • 2pm–5pm182 flights60.9%
  • 5pm–8pm327 flights66.7%
  • 8pm–5am34 flights72.7%

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

Book the early departure. Flights leaving between 5am–8am arrive on time 91.4% of the time, against 60.9% for the afternoon window. That is 31 points of difference for no extra money, and it comes from the same aircraft having had no earlier flight to fall behind on. The 5pm–8pm window is the busiest, with 327 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.

On-time rate by calendar month76J83F62M87A80M61J69J74A77S71O83N66D
Darker means more delays. Figures are on-time percentages.April best, June worst

June is the worst month at 60.7% on time, 26 points below April, the best at 86.5%. 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. March was the busiest month here, with 109 flights.

Across the week, Wednesday is the strongest day at 81.4% on time and Thursday the weakest at 68.7%. 13 points is a smaller lever than departure hour, but it is free.

On-time rate by day of the week71.2Mon74.8Tue81.4Wed68.7Thu71.9Fri78.5Sat71.4Sun
Monday: 71.2 percent on time. Tuesday: 74.8 percent on time. Wednesday: 81.4 percent on time. Thursday: 68.7 percent on time. Friday: 71.9 percent on time. Saturday: 78.5 percent on time. Sunday: 71.4 percent on time

Delay causes

Why this route gets delayed

One category carries most of the weight here. Late-arriving aircraft accounts for 45% of the 16,000 delay minutes carriers reported, and the remaining four split what is left. The split is by minutes rather than by flights, so a few very long delays count for as much as many short ones.

  • Late-arriving aircraft
    45%
  • Carrier
    32%
  • National Airspace System
    20%
  • Security
    2%
  • Extreme weather
    2%

45% 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 16,000 reported delay minutes here, that single category outweighs weather by 25 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 16,369 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 91.4% on time here.

Cancellations sit at 1.51% against a national 1.81%, which is ordinary. Diversions add another 0.18%.

Connections and stage length

What a delay here actually costs

7.5% of arrivals land an hour or more late, close to the national 8.1%. That is the figure that decides a connection, and it says a 60 to 75 minute layover is reasonable here while anything under 45 minutes is a bet. Most delays on this route last about an hour, which a normal layover absorbs.

The 1,167 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 70.9% on time across 1,128 flights, 3 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 3 points of difference.

The sample behind these figures is 1,127 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.

Work out the risk of missing a connection in FLL after this flight

What to do with this

Booking this route

Put together: the calendar is the biggest lever here, not the carrier or the hour. April runs 86.5% on time and June 60.7%, a swing of 26 points. If the dates move at all, move them out of June before you think about anything else. 1,108 completed flights over 12 months sit behind that.

Common questions

MDW to FLL questions

How often is MDW to FLL delayed?

About one flight in four arrives at least 15 minutes late, which is the Department of Transportation's definition of a delayed arrival. That works out to 26.0% of the 1,127 flights in this analysis, against 22.4% nationally. Delayed flights are late by about an hour on average.

How reliable is MDW to FLL compared with the rest of the country?

74.0% of flights arrive on time here against a national 77.6%, a difference of 4 points against it. That is worth a C on this site's grading scale.

What time of day has the fewest delays on MDW to FLL?

The 5am–8am departure window is the strongest at 91.4% on time. The 2pm–5pm window is the weakest at 60.9%, 31 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 MDW to FLL?

June is the weakest month at 60.7% on time, compared with 86.5% in April. 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.

Related

Where to go next

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

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Source: US DOT Bureau of Transportation Statistics, on-time performance data, July 2025 to June 2026. Last updated 15 September 2026; recomputed monthly. How this data is collected.