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DelayAtlas

Carrier performance at one airport

WNMCI

Southwest Airlines at Kansas City International

Departures
23,245
Period
June 2025 to May 2026
Routes
25
Rank here
#6 of 11
B+GRADE

Southwest Airlines at Kansas City lands a B+, about a point better than the national rate of 77.4%. Roughly one flight in five arrive 15 minutes late or worse, and those flights are late by about 55 minutes on average. That is a workable record, not a spotless one. That rests on 23,245 flights, of which Delta Air Lines flew 7,964 at 86.1% on time.

Measured against the airport rather than the country, Southwest Airlines runs about a point behind the 79.3% weighted average across all carriers at MCI. That is the comparison worth making: every operator here works the same runways, the same airspace and the same weather.

Key figures

On time

78.2%

22,986 completed departures

Avg delay

54 min

Across delayed flights only

Cancelled

0.82%

At MCI, this carrier only

Rank here

#6

Of 11 carriers clearing the floor at MCI

These figures cover 23,000 flights between June 2025 and May 2026. The median arrival is 3 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.

Against the competition

Every carrier at MCI, ranked

The choice of carrier is not cosmetic here. Delta Air Lines arrives on time 86.1% of the time; Frontier Airlines manages 70.0%. Sample sizes sit next to every figure, because a two-point gap across 477 flights means less than a ten-point one.

On-time performance of all carriers departing MCI
AirlineFlightsOn timeAvg delayCancelledGrade
Delta Air Lines7,96486.1%89 min1.93%A
Alaska Airlines99583.2%62 min0.80%B+
Spirit Airlines92181.2%72 min2.61%B
Republic Airways1,62680.9%90 min2.28%B
Envoy Air1,73778.5%71 min2.42%B
Southwest Airlines (this page)23,24578.2%54 min0.82%B+
SkyWest Airlines1,99577.7%99 min2.11%B
United Airlines3,30277.5%70 min0.97%B+
American Airlines5,19876.9%106 min2.37%B
PSA Airlines1,05070.1%111 min7.62%C−
Frontier Airlines47770.0%95 min0.84%C+

PSA Airlines cancels 7.6% of what it schedules here, the highest in the table. A cancelled flight never appears in an on-time rate, so read that column alongside the punctuality one rather than after it.

Route by route

Where Southwest Airlines flies from MCI

Southwest Airlines operates 25 routes out of MCI with enough volume to report. Route records inside one carrier at one airport still spread widely, because a short shuttle and a transcontinental have very different exposure to a late inbound.

Southwest Airlines routes from MCI
RouteFlightsOn timeAvg delayCancelledGrade
MCI to DEN · Denver2,33371.8%59 min0.73%C+
MCI to MDW · Chicago2,09779.9%54 min1.10%B
MCI to DAL · Dallas2,03381.4%59 min1.18%B
MCI to LAS · Las Vegas1,68680.6%49 min0.24%B+
MCI to PHX · Phoenix1,63176.9%55 min0.55%B+
MCI to BNA · Nashville1,37982.6%56 min0.65%B+
MCI to MCO · Orlando1,22978.4%51 min0.57%B+
MCI to STL · St. Louis1,02086.5%47 min0.49%A+
MCI to HOU · Houston1,00381.5%51 min0.70%B+
MCI to DCA · Washington99973.3%60 min1.30%C
MCI to BWI · Baltimore89181.6%51 min2.02%B
MCI to AUS · Austin85380.8%54 min0.35%B+
MCI to LGA · New York75276.7%60 min3.99%B−
MCI to TPA · Tampa64577.4%55 min0.31%B+
MCI to LAX · Los Angeles46767.1%48 min0.43%C+
MCI to FLL · Fort Lauderdale41973.8%52 min1.19%C
MCI to SAN · San Diego39579.2%44 min0.25%B+
MCI to MSY · New Orleans38176.0%57 min0.26%B+
MCI to ATL · Atlanta36577.4%62 min0.27%B+
MCI to IND · Indianapolisthin sample35075.4%42 min0.00%B+
MCI to MKE · Milwaukeethin sample35077.3%48 min0.57%B+
MCI to SAT · San Antoniothin sample27976.3%65 min0.36%B+
MCI to ABQ · Albuquerquethin sample26785.7%66 min0.75%A+
MCI to RSW · Fort Myersthin sample23679.3%56 min1.27%B
MCI to OAK · Oaklandthin sample22061.8%40 min0.45%D+

Departure window

Best time of day for this operation

Departure time matters more here than the choice of carrier. The gap between the best and worst window is 31 points, against 16 points between the best and worst carrier. Each bar is the on-time rate for flights scheduled inside that window.

  • 5am–8am4,904 flights93.0%
  • 8am–11am3,205 flights87.6%
  • 11am–2pm4,510 flights82.4%
  • 2pm–5pm5,121 flights71.3%
  • 5pm–8pm4,160 flights62.1%
  • 8pm–5am1,345 flights62.1%

Scale runs 55% to 100%. Rows with fewer than 30 flights show a dash.

The 8pm–5am window is where this operation falls apart: 62.1% on time, against 93.0% 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.

Across the year

Seasonal pattern

On-time rate by calendar month86J84F78M80A74M71J72J78A82S78O81N76D
Darker means more delays. Figures are on-time percentages.January best, June worst

June is the worst month at 71.0% on time, 15 points below January, 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.

Delay causes

What holds this operation up

  • Late-arriving aircraft
    52%
  • National Airspace System
    23%
  • Carrier
    22%
  • Extreme weather
    4%
  • Security
    0%

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 272,000 reported delay minutes here, that single category outweighs weather by 14 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.

Cancellations are rare at 0.82%, below the national 1.80% 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.

6.1% of arrivals land an hour or more late, close to the national 8.2%. 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 55 minutes kind, which a normal layover absorbs.

23,245 flights sit behind these numbers, which is a large enough sample that the headline rate is not moving on noise. Where a sub-group falls below 30 flights the site shows a dash instead of a percentage.

Put together: the calendar is the biggest lever here, not the carrier or the hour. January runs 86.3% on time and June 71.0%, a swing of 15 points. If the dates move at all, move them out of June before you think about anything else.

Common questions

Southwest Airlines at MCI

How often is Southwest Airlines at MCI delayed?

Roughly one flight in five arrive at least 15 minutes late, which is the Department of Transportation's definition of a delayed arrival. That works out to 21.8% of the 23,245 flights in this analysis, against 22.6% nationally. Delayed flights are late by about 55 minutes on average.

Which airline is most reliable on Southwest Airlines at MCI?

Delta Air Lines leads at 86.1% on time across 7,964 flights. Frontier Airlines is at the other end on 70.0%, a gap of 16 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 Southwest Airlines at MCI?

The 5am–8am departure window is the strongest at 93.0% on time. The 8pm–5am window is the weakest at 62.1%, 31 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 Southwest Airlines at MCI?

June is the weakest month at 71.0% on time, compared with 86.3% in January. 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

Source: US DOT Bureau of Transportation Statistics, on-time performance data, June 2025 to May 2026. Updated monthly. How this data is collected.