Route reliability record
ATL→MCI
Atlanta to Kansas City
- Flights
- 3,281
- Period
- July 2025 to June 2026
- Distance
- 692 mi
- Carriers
- 4
This route lands a B, 5 points better than the national rate of 77.6%. About one flight in six arrive 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 3,281 flights, of which Delta Air Lines flew 2,758 at 84.6% on time.
Set against the rest of the country, this route's record is 5 points better than the US average of 77.6%. That gap is worth roughly 52 fewer late arrivals for every thousand flights.
Key figures
On time
82.8%
Arrivals under 15 minutes late, of 3,236 completed flights
Avg delay
58 min
Across delayed arrivals only, not all flights
Cancelled
1.19%
National rate is 1.81%
Best carrier
Delta
84.6% on time across 2,758 flights
These figures cover 3,281 flights between July 2025 and June 2026. The median arrival is 4 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 ATL to MCI
The choice of carrier is not cosmetic here. Delta Air Lines arrives on time 84.6% of the time; Southwest Airlines manages 75.9%. Sample sizes sit next to every figure, because a two-point gap across 365 flights means less than a ten-point one.
| Airline | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| SkyWest Airlinesthin sample | 1 | 100.0% | — | 0.00% | A+ |
| Delta Air Lines | 2,758 | 84.6% | 57 min | 1.38% | B |
| Southwest Airlines | 365 | 75.9% | 50 min | 0.00% | B+ |
| Frontier Airlinesthin sample | 157 | 68.6% | 77 min | 0.64% | C+ |
Delta leads Southwest by 9 points. Real, but small enough that a better departure time on the weaker carrier can outweigh it.
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 11 points, against 9 points between the best and worst carrier. Each bar is the on-time rate for flights scheduled inside that window.
- 5am–8am1 flights—
- 8am–11am707 flights86.9%
- 11am–2pm593 flights87.1%
- 2pm–5pm933 flights80.1%
- 5pm–8pm324 flights76.2%
- 8pm–5am723 flights81.7%
Scale runs 70% to 95%. Rows with fewer than 30 flights show a dash.
The best window here is not the first bank but the 11am–2pm slot at 87.1% on time, ahead of 5pm–8pm at 76.2%. Where the curve peaks mid-day rather than at dawn, the constraint is usually congestion at one end rather than the aircraft's own rotation. The 2pm–5pm window is the busiest, with 933 flights scheduled in it.
Across the year
When delays peak on this route
This route's year swings by 15 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.
September is the best month on the calendar at 90.3% on time. Shoulder season thins the schedule and takes the summer weather with it, and the operation gets its margin back. October was the busiest month here, with 307 flights.
Across the week, Wednesday is the strongest day at 85.7% on time and Sunday the weakest at 79.8%. 6 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. Carrier accounts for 47% of the 32,000 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.
- 47%Carrier
- 29%Late-arriving aircraft
- 19%National Airspace System
- 4%Extreme weather
- 1%Security
The largest share of delay minutes, 47%, 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 15,000 of the 32,000 delay minutes reported here. The split is drawn from 32,104 reported delay minutes.
Cancellations sit at 1.19% against a national 1.81%, which is ordinary. Diversions add another 0.18%.
Connections and stage length
What a delay here actually costs
5.1% 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 are the about an hour kind, which a normal layover absorbs.
The 692 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 87.4% on time across 3,281 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 3,281 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 calendar is the biggest lever here, not the carrier or the hour. September runs 90.3% on time and March 75.0%, a swing of 15 points. If the dates move at all, move them out of March before you think about anything else. 3,236 completed flights over 12 months sit behind that.
Common questions
ATL to MCI questions
How often is ATL to MCI delayed?
About one flight in six arrive at least 15 minutes late, which is the Department of Transportation's definition of a delayed arrival. That works out to 17.2% of the 3,281 flights in this analysis, against 22.4% nationally. Delayed flights are late by about an hour on average.
Which airline is most reliable on ATL to MCI?
Delta Air Lines leads at 84.6% on time across 2,758 flights. Southwest Airlines is at the other end on 75.9%, a gap of 9 points. Sample size matters as much as the percentage: a rate built from a few hundred flights moves around far more than one built from ten thousand.
What time of day has the fewest delays on ATL to MCI?
The 11am–2pm departure window is the strongest at 87.1% on time. The 5pm–8pm window is the weakest at 76.2%, 11 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 March delays on ATL to MCI?
March is the weakest month at 75.0% on time, compared with 90.3% in September. Across the year that is 15 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
- MCI to ATL — the return legseparate record
- Hartsfield-Jackson Atlanta International (ATL) delay statistics
- Kansas City International (MCI) delay statistics
- SkyWest Airlines on-time record100.0%
- Delta Air Lines on-time record84.6%
- Southwest Airlines on-time record75.9%
- The best time of day to fly, according to 7.04 million flight records
- Worst months to fly in the US, ranked by the data
Direction matters. ATL to MCI and MCI to ATL 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.