Route reliability record
FLL→STL
Fort Lauderdale to St. Louis
- Flights
- 843
- Period
- July 2025 to June 2026
- Distance
- 1,057 mi
- Carriers
- 3
This route lands a B+, level with the national rate of 77.6%. Roughly one flight in four arrives 15 minutes late or worse, and those flights are late by about an hour on average. That is a workable record, not a spotless one. That rests on 843 FLL to STL flights, with a median arrival 6 minutes early.
Best time to fly FLL to STL: a 5am–8am departure, ideally on a Tuesday. Flights in that window arrived on time 96.1% of the time and Tuesday flights 92.4%, against 77.7% 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
77.7%
Arrivals under 15 minutes late, of 839 completed flights
Avg delay
55 min
Across delayed arrivals only, not all flights
Cancelled
0.47%
National rate is 1.81%
Best carrier
Southwest
78.2% on time across 766 flights
These figures cover 843 flights between July 2025 and June 2026. The median arrival is 6 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 FLL to STL
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 |
|---|---|---|---|---|---|
| Southwest Airlines | 766 | 78.2% | 55 min | 0.39% | B+ |
| Spirit Airlinesthin sample | 73 | 73.6% | 55 min | 1.37% | C |
| Frontier Airlinesthin sample | 4 | 50.0% | 84 min | 0.00% | F+ |
Best ways to make this trip
The most reliable ways to fly Fort Lauderdale to St. Louis
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. FLL → STLFort Lauderdale to St. Louis | Southwest Airlines | 77.9% | 78.2% | 0.39% | 5am–8am, Tue (route) | — |
| 2. MIA → STLMiami to St. Louis | American Airlines | 73.1% | 73.8% | 1.00% | 8am–11am, Wed | — |
| 3. MIA → STLMiami to St. Louis | Southwest Airlines | 66.6% | 66.9% | 0.45% | 5am–8am, Sat | — |
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 40 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–8am336 flights96.1%
- 8am–11am91 flights83.5%
- 11am–2pm91 flights78.0%
- 2pm–5pm84 flights55.6%
- 5pm–8pm187 flights56.7%
- 8pm–5am54 flights59.3%
Scale runs 45% to 100%. Rows with fewer than 30 flights show a dash.
Book the early departure. Flights leaving between 5am–8am arrive on time 96.1% of the time, against 55.6% for the afternoon window. That is 40 points of difference for no extra money, and it comes from the same aircraft having had no earlier flight to fall behind on. The 5am–8am window is the busiest, with 336 flights scheduled in it.
Across the year
When delays peak on this route
This route's year swings by 29 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.
February is the weak month at 68.8% on time, against 97.8% in September. Winter delays cluster: a single storm system can account for most of a month's shortfall, so an average December hides both very good weeks and genuinely unflyable days. March was the busiest month here, with 84 flights.
Across the week, Tuesday is the strongest day at 92.4% on time and Friday the weakest at 68.7%. 24 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 10,000 reported delay minutes.
- 41%Late-arriving aircraft
- 40%Carrier
- 16%National Airspace System
- 3%Extreme weather
- 0%Security
41% 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 10,000 reported delay minutes here, that single category outweighs weather by 16 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 10,319 reported delay minutes.
The largest share of delay minutes, 40%, 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 4,093 of the 10,000 delay minutes reported here.
Cancellations are rare at 0.47%, 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
6.2% 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 73.9% on time across 841 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.
One caution: this is a thin sample. 843 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 STL after this flight
What to do with this
Booking this route
Put together: treat all of this as provisional. 843 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 77.7% headline is the most reliable number on the page; the hour and month splits below it are built on a few dozen flights each. 839 completed flights over 12 months sit behind that.
Common questions
FLL to STL questions
How often is FLL to STL delayed?
Roughly 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 22.3% of the 843 flights in this analysis, against 22.4% nationally. Delayed flights are late by about an hour on average.
How reliable is FLL to STL compared with the rest of the country?
77.7% of flights arrive on time here against a national 77.6%, a difference of half a point in its favour. That is worth a B+ on this site's grading scale.
What time of day has the fewest delays on FLL to STL?
The 5am–8am departure window is the strongest at 96.1% on time. The 2pm–5pm window is the weakest at 55.6%, 40 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 February delays on FLL to STL?
February is the weakest month at 68.8% on time, compared with 97.8% in September. Across the year that is 29 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
- STL to FLL — the return legseparate record
- Fort Lauderdale-Hollywood International (FLL) delay statistics
- St. Louis Lambert International (STL) delay statistics
- FLL to ATL, a related route71.8%
- ATL to STL, a related route82.4%
- FLL to EWR, a related route70.4%
- Southwest Airlines on-time record78.2%
- Spirit Airlines on-time record73.6%
- Frontier Airlines on-time record50.0%
- 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. FLL to STL and STL to FLL are scored separately because they are separate operations, with different departure banks and different aircraft. Compare the return leg.
Embed FLL to STL’s on-time badge on your site
Paste this into a web page. The badge shows the current on-time rate, cancellation rate and grade, and updates every month. Preview it, or build a badge for another route or airport.
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.