Carrier route record
WNMCI→LAX
Southwest Airlines · Kansas City to Los Angeles
- Flights
- 499
- Period
- July 2025 to June 2026
- Share of route
- 39%
- Carriers
- 4
Historical statistics for July 2025 to June 2026, not live status. For today’s flights, check with Southwest Airlines.
Southwest on MCI to LAX draws a C+. About one flight in three arrives at least 15 minutes late, and the typical late arrival is roughly 50 minutes behind schedule. Build slack into anything you connect to. That rests on 499 flights, with a median arrival 3 minutes late.
The national on-time rate over the same period is 77.6%, so Southwest on MCI to LAX runs 11 points behind the country as a whole. Across a thousand flights that is about 110 extra late arrivals.
Key figures
On time
66.6%
Arrivals under 15 minutes late, of 497 completed flights
Avg delay
51 min
Across delayed arrivals only, not all flights
Cancelled
0.40%
National rate is 1.81%
Whole route
82.0%
Every carrier on MCI to LAX, 1,290 flights
These figures cover 499 flights between July 2025 and June 2026. Beyond the headline rate, 9.5% 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
Southwest against every carrier on MCI to LAX
Southwest flew 499 of the 1,290 flights on MCI to LAX, about 39% of it. Its 66.6% on time is 15 points worse than the route as a whole, which runs 82.0%. Ranked by on-time rate it is last of four carriers on the route, where the range runs from SkyWest at 92.9% to Southwest at 66.6%. Two of those carriers flew fewer than 365 flights here, so treat their positions as rough.
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 |
|---|---|---|---|---|---|
| SkyWest Airlinesthin sample | 85 | 92.9% | 66 min | 0.00% | A+ |
| Delta Air Lines | 619 | 92.2% | 77 min | 0.97% | A+ |
| Spirit Airlinesthin sample | 87 | 88.4% | 90 min | 1.15% | A |
| Southwest Airlines (this page) | 499 | 66.6% | 51 min | 0.40% | C+ |
Departure window
When Southwest runs best on this route
Departure time matters more here than the choice of carrier. The gap between the best and worst window is 38 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–8am63 flights88.7%
- 8am–11am49 flights83.3%
- 11am–2pm30 flights70.0%
- 2pm–5pm103 flights69.9%
- 5pm–8pm126 flights61.9%
- 8pm–5am128 flights50.8%
Scale runs 40% to 95%. Rows with fewer than 30 flights show a dash.
The 8pm–5am window is where this operation falls apart: 50.8% on time, against 88.7% 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 8pm–5am window is the busiest, with 128 flights scheduled in it.
Across the year
Southwest on MCI to LAX through the year
Delays peak in October, when the on-time rate falls to 56.4%. January is the strongest month at 85.7%. Moving a flexible trip across that boundary buys 29 points. June was the busiest month here, with 66 flights.
Across the week, Tuesday is the strongest day at 75.0% on time and Sunday the weakest at 55.6%. 19 points is a smaller lever than departure hour, but it is free.
Delay causes
Why Southwest runs late on this route
One category carries most of the weight here. Late-arriving aircraft accounts for 56% of the 8,487 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.
- 56%Late-arriving aircraft
- 31%Carrier
- 10%National Airspace System
- 3%Extreme weather
- 0%Security
56% 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 8,487 reported delay minutes here, that single category outweighs weather by 18 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 8,487 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 88.7% on time here.
Cancellations are rare at 0.40%, 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 costs
For anyone connecting, the number to weigh is not the on-time rate but the tail behind it. 9.5% 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 1,363 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 75.3% on time across 498 flights, 9 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 9 points of difference.
One caution: this is a thin sample. 499 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.
What to do with this
Booking Southwest on MCI to LAX
Put together: treat all of this as provisional. 499 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 66.6% headline is the most reliable number on the page; the hour and month splits below it are built on a few dozen flights each. 497 completed flights over 12 months sit behind that.
Related
Where to go next
- MCI to LAX, every carrier
- Southwest on LAX to MCI, the return leg
- Delta Air Lines on MCI to LAX92.2%
- Southwest Airlines network-wide record
- Kansas City International (MCI) delay statistics
- Los Angeles International (LAX) delay statistics
- Why the first flight of the morning is statistically safest
- The best time of day to fly, according to 7.04 million flight records
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.