Route reliability record
CLT→STL
Charlotte to St. Louis
- Flights
- 1,826
- Period
- July 2025 to June 2026
- Distance
- 575 mi
- Carriers
- 3
This route lands a B, about a point better than the national rate of 77.6%. About one flight in five arrives 15 minutes late or worse, and those flights are late by a little over an hour on average. That is a workable record, not a spotless one. That rests on 1,826 CLT to STL flights, with a median arrival 6 minutes early.
Best time to fly CLT to STL: a 5am–8am departure, ideally on a Wednesday. Flights in that window arrived on time 89.4% of the time and Wednesday flights 84.5%, against 78.7% 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
78.7%
Arrivals under 15 minutes late, of 1,793 completed flights
Avg delay
70 min
Across delayed arrivals only, not all flights
Cancelled
1.48%
National rate is 1.81%
Best carrier
American
77.6% on time across 1,487 flights
These figures cover 1,826 flights between July 2025 and June 2026. Beyond the headline rate, 8.3% 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 CLT 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 |
|---|---|---|---|---|---|
| PSA Airlinesthin sample | 75 | 88.4% | 71 min | 6.67% | A− |
| Southwest Airlinesthin sample | 264 | 82.4% | 68 min | 1.14% | B |
| American Airlines | 1,487 | 77.6% | 70 min | 1.28% | B |
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 16 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–8am226 flights89.4%
- 8am–11am178 flights84.8%
- 11am–2pm375 flights81.2%
- 2pm–5pm269 flights73.8%
- 5pm–8pm503 flights74.2%
- 8pm–5am275 flights75.3%
Scale runs 65% to 95%. Rows with fewer than 30 flights show a dash.
Book the early departure. Flights leaving between 5am–8am arrive on time 89.4% of the time, against 73.8% for the afternoon window. That is 16 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 503 flights scheduled in it.
Across the year
When delays peak on this route
This route's year swings by 23 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.
July is the worst month at 63.7% on time, 23 points below September, the best at 86.3%. 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. July was the busiest month here, with 171 flights.
Across the week, Wednesday is the strongest day at 84.5% on time and Monday the weakest at 69.8%. 15 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 52% of the 27,000 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.
- 52%Late-arriving aircraft
- 34%Carrier
- 7%National Airspace System
- 6%Extreme weather
52% 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 27,000 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 26,702 reported delay minutes.
The largest share of delay minutes, 34%, 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 9,177 of the 27,000 delay minutes reported here.
Cancellations sit at 1.48% against a national 1.81%, which is ordinary. Diversions add another 0.33%.
Connections and stage length
What a delay here actually costs
8.3% 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 a little over an hour, which a normal layover absorbs.
The 575 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 83.5% on time across 1,827 flights, 5 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 5 points of difference.
The sample behind these figures is 1,826 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 STL 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. September runs 86.3% on time and July 63.7%, a swing of 23 points. If the dates move at all, move them out of July before you think about anything else. 1,793 completed flights over 12 months sit behind that.
Common questions
CLT to STL questions
How often is CLT to STL delayed?
About one flight in five arrives at least 15 minutes late, which is the Department of Transportation's definition of a delayed arrival. That works out to 21.3% of the 1,826 flights in this analysis, against 22.4% nationally. Delayed flights are late by a little over an hour on average.
How reliable is CLT to STL compared with the rest of the country?
78.7% of flights arrive on time here against a national 77.6%, a difference of about 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 CLT to STL?
The 5am–8am departure window is the strongest at 89.4% on time. The 2pm–5pm window is the weakest at 73.8%, 16 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 July delays on CLT to STL?
July is the weakest month at 63.7% on time, compared with 86.3% in September. Across the year that is 23 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 CLT — the return legseparate record
- Charlotte Douglas International (CLT) delay statistics
- St. Louis Lambert International (STL) delay statistics
- Southwest Airlines on CLT to STL82.4%
- American Airlines on CLT to STL77.6%
- CLT to MCO, a related route70.6%
- ATL to STL, a related route82.4%
- CLT to ATL, a related route83.3%
- PSA Airlines on-time record88.4%
- Southwest Airlines on-time record82.4%
- American Airlines on-time record77.6%
- 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. CLT to STL and STL to CLT 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.