Route reliability record
STL→FLL
St. Louis to Fort Lauderdale
- Flights
- 841
- Period
- July 2025 to June 2026
- Distance
- 1,057 mi
- Carriers
- 3
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 841 STL to FLL flights, with a median arrival 2 minutes early.
Best time to fly STL to FLL: a 5am–8am departure, ideally on a Wednesday. Flights in that window arrived on time 90.3% of the time and Wednesday flights 90.2%, against 73.9% 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
73.9%
Arrivals under 15 minutes late, of 835 completed flights
Avg delay
57 min
Across delayed arrivals only, not all flights
Cancelled
0.48%
National rate is 1.81%
Best carrier
Southwest
74.1% on time across 764 flights
These figures cover 841 flights between July 2025 and June 2026. The median arrival is 2 minutes early, which is the part an average hides: most flights here are fine, and the on-time rate is decided by a tail of badly late ones. On-time means under 15 minutes late, the DOT's own threshold.
Carrier by carrier
Which airline is most reliable on STL 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.
| Airline | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| Frontier Airlinesthin sample | 4 | 75.0% | 341 min | 0.00% | B+ |
| Southwest Airlines | 764 | 74.1% | 54 min | 0.39% | C+ |
| Spirit Airlinesthin sample | 73 | 71.8% | 75 min | 1.37% | C |
Best ways to make this trip
The most reliable ways to fly St. Louis 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. 2 of the top 3 use a different airport at one end.
| Option | Airline | Success | On time | Cancelled | Best departure | Most punctual flight |
|---|---|---|---|---|---|---|
| 1. STL → MIASt. Louis to Miami | American Airlines | 87.7% | 88.6% | 0.99% | 5am–8am, Wed | — |
| 2. STL → MIASt. Louis to Miami | Southwest Airlines | 75.3% | 75.6% | 0.45% | 8am–11am, Wed | — |
| 3. STL → FLLSt. Louis to Fort Lauderdale | Southwest Airlines | 73.8% | 74.1% | 0.39% | 5am–8am, Wed (route) | — |
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.
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 half a point between the best and worst carrier. Each bar is the on-time rate for flights scheduled inside that window.
- 5am–8am72 flights90.3%
- 8am–11am267 flights83.8%
- 11am–2pm71 flights64.3%
- 2pm–5pm100 flights57.6%
- 5pm–8pm222 flights74.0%
- 8pm–5am109 flights59.6%
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 90.3% of the time, against 57.6% for the afternoon window. That is 33 points of difference for no extra money, and it comes from the same aircraft having had no earlier flight to fall behind on. The 8am–11am window is the busiest, with 267 flights scheduled in it.
Across the year
When delays peak on this route
This route's year swings by 22 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.
June is the worst month at 65.2% on time, 22 points below September, the best at 86.7%. 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 85 flights.
Across the week, Wednesday is the strongest day at 90.2% on time and Sunday the weakest at 68.9%. 21 points is a smaller lever than departure hour, but it is free.
Delay causes
Why this route gets delayed
One category carries most of the weight here. Late-arriving aircraft accounts for 54% of the 12,000 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.
- 54%Late-arriving aircraft
- 20%National Airspace System
- 20%Carrier
- 5%Extreme weather
- 1%Security
54% 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 12,000 reported delay minutes here, that single category outweighs weather by 10 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 12,485 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 90.3% on time here.
Cancellations are rare at 0.48%, below the national 1.81% and low enough to earn the plus on the grade. Roughly one flight in 100 is called off; the risk here is arriving late, not not arriving.
Connections and stage length
What a delay here actually costs
7.4% 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 1,057 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 77.7% on time across 843 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.
One caution: this is a thin sample. 841 flights over twelve months is enough to clear this site's floor but not enough to pin the rate down tightly, and a single bad week moves it by more than a point. Treat the grade as a rough reading.
Work out the risk of missing a connection in FLL after this flight
What to do with this
Booking this route
Put together: treat all of this as provisional. 841 flights over twelve months is enough to clear this site's floor and not enough to be confident to better than a couple of points. The 73.9% headline is the most reliable number on the page; the hour and month splits below it are built on a few dozen flights each. 835 completed flights over 12 months sit behind that.
Common questions
STL to FLL questions
How often is STL 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 26.1% of the 841 flights in this analysis, against 22.4% nationally. Delayed flights are late by about an hour on average.
How reliable is STL to FLL compared with the rest of the country?
73.9% 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 STL to FLL?
The 5am–8am departure window is the strongest at 90.3% on time. The 2pm–5pm window is the weakest at 57.6%, 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 June delays on STL to FLL?
June is the weakest month at 65.2% on time, compared with 86.7% in September. Across the year that is 22 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
- FLL to STL — the return legseparate record
- St. Louis Lambert International (STL) delay statistics
- Fort Lauderdale-Hollywood International (FLL) delay statistics
- STL to ATL, a related route85.3%
- ATL to FLL, a related route70.7%
- STL to DEN, a related route74.9%
- Frontier Airlines on-time record75.0%
- Southwest Airlines on-time record74.1%
- Spirit Airlines on-time record71.8%
- Why the first flight of the morning is statistically safest
- The best time of day to fly, according to 7.04 million flight records
Direction matters. STL to FLL and FLL to STL 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.