Route reliability record
STL→DFW
St. Louis to Dallas-Fort Worth
- Flights
- 2,380
- Period
- July 2025 to June 2026
- Distance
- 550 mi
- Carriers
- 5
This route carries a cancellation problem, not just a delay problem: 3.4% of scheduled flights never operate, against 1.8% nationally. Of the ones that do fly, close to three flights in four arrive on time, worth a C− overall. The punctuality figure counts only flights that actually departed, so it flatters an operation that cancels this often. That rests on 2,380 flights, with a median arrival 6 minutes early.
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
74.5%
Arrivals under 15 minutes late, of 2,291 completed flights
Avg delay
111 min
Across delayed arrivals only, not all flights
Cancelled
3.40%
National rate is 1.81%
Best carrier
American
74.8% on time across 1,852 flights
These figures cover 2,380 flights between July 2025 and June 2026. Beyond the headline rate, 12.2% 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 STL to DFW
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 |
|---|---|---|---|---|---|
| Envoy Airthin sample | 299 | 82.8% | 72 min | 3.01% | B− |
| American Airlines | 1,852 | 74.8% | 114 min | 3.46% | C− |
| Frontier Airlinesthin sample | 80 | 70.1% | 80 min | 2.50% | C |
| PSA Airlinesthin sample | 51 | 58.3% | 150 min | 5.88% | D− |
| SkyWest Airlinesthin sample | 98 | 54.7% | 127 min | 3.06% | F− |
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–8am699 flights85.5%
- 8am–11am553 flights79.2%
- 11am–2pm406 flights73.3%
- 2pm–5pm267 flights73.3%
- 5pm–8pm448 flights53.0%
- 8pm–5am7 flights—
Scale runs 45% to 90%. Rows with fewer than 30 flights show a dash.
The 5pm–8pm window is where this operation falls apart: 53.0% on time, against 85.5% 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 5am–8am window is the busiest, with 699 flights scheduled in it.
Across the year
When delays peak on this route
This route's year swings by 20 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 65.3% on time, 20 points below February, the best at 85.4%. 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. June was the busiest month here, with 240 flights.
Across the week, Tuesday is the strongest day at 81.4% on time and Monday the weakest at 65.8%. 16 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 45% of the 65,000 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.
- 45%Late-arriving aircraft
- 31%Carrier
- 18%National Airspace System
- 6%Extreme weather
- 0%Security
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 65,000 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 65,037 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 85.5% on time here.
Cancellations run at 3.40%, against 1.81% nationally. That is about one flight in 30 cancelled outright. A cancelled flight is invisible in every on-time figure on this page, so the punctuality numbers above describe only the flights that actually operated.
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. 12.2% 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 550 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 69.4% on time across 2,382 flights, 5 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 5 points of difference.
The sample behind these figures is 2,380 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 delay figures matter less here than the 3.40% cancellation rate. A late arrival costs you close to two hours; a cancelled flight costs you the day. Book the 5am–8am departure so there is still a schedule behind you if it goes wrong, and treat a same-day connection as optimistic. 2,291 completed flights over 12 months sit behind that.
Common questions
STL to DFW questions
How often is STL to DFW delayed?
About one flight in four arrive at least 15 minutes late, which is the Department of Transportation's definition of a delayed arrival. That works out to 25.5% of the 2,380 flights in this analysis, against 22.4% nationally. Delayed flights are late by close to two hours on average.
How reliable is STL to DFW compared with the rest of the country?
74.5% of flights arrive on time here against a national 77.6%, a difference of 3 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 DFW?
The 5am–8am departure window is the strongest at 85.5% on time. The 5pm–8pm window is the weakest at 53.0%, 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 DFW?
June is the weakest month at 65.3% on time, compared with 85.4% in February. Across the year that is 20 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
- DFW to STL — the return legseparate record
- St. Louis Lambert International (STL) delay statistics
- Dallas/Fort Worth International (DFW) delay statistics
- Envoy Air on-time record82.8%
- American Airlines on-time record74.8%
- Frontier Airlines on-time record70.1%
- Why the first flight of the morning is statistically safest
- What a cancellation rate actually tells you (and what it hides)
Direction matters. STL to DFW and DFW to STL 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.