Carrier route record

WNMIA→MCI

Southwest Airlines · Miami to Kansas City

Flights: 182
Period: July 2025 to June 2026
Share of route: 23%
Carriers: 4

Historical statistics for July 2025 to June 2026, not live status. For today’s flights, check with Southwest Airlines.

Southwest on MIA to MCI draws a D+. Roughly one flight in three arrives at least 15 minutes late, and the typical late arrival is a little over an hour behind schedule. Build slack into anything you connect to. That rests on 182 flights, with a median arrival 4 minutes late.

The national on-time rate over the same period is 77.6%, so Southwest on MIA to MCI runs 14 points behind the country as a whole. Across a thousand flights that is about 144 extra late arrivals.

On time

63.2%

Arrivals under 15 minutes late, of 182 completed flights

Avg delay

72 min

Across delayed arrivals only, not all flights

Cancelled

0.00%

National rate is 1.81%

Whole route

72.8%

Every carrier on MIA to MCI, 801 flights

These figures cover 182 flights between July 2025 and June 2026. Beyond the headline rate, 12.1% 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 MIA to MCI

Southwest flew 182 of the 801 flights on MIA to MCI, about 23% of it. Its 63.2% on time is 10 points worse than the route as a whole, which runs 72.8%. Ranked by on-time rate it is last of four carriers on the route, where the range runs from Republic at 100.0% to Southwest at 63.2%. 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.

On-time performance by carrier on MIA to MCI
Airline	Flights	On time	Avg delay	Cancelled	Grade
Republic Airwaysthin sample	5	100.0%	—	0.00%	A+
Envoy Airthin sample	154	88.8%	42 min	1.30%	A
American Airlines	460	71.0%	73 min	1.52%	C
Southwest Airlines (this page)thin sample	182	63.2%	72 min	0.00%	D+

Departure window

When Southwest runs best on this route

Departure time is the single lever a traveller controls, and it moves the odds more than most people expect. Each bar below is the on-time rate for flights scheduled to leave inside that window, across 182 flights.

5am–8am—
8am–11am—
11am–2pm69 flights68.1%
2pm–5pm106 flights61.3%
5pm–8pm1 flights—
8pm–5am6 flights—

Scale runs 55% to 75%. Rows with fewer than 30 flights show a dash.

The best window here is not the first bank but the 11am–2pm slot at 68.1% on time, ahead of 2pm–5pm at 61.3%. 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 106 flights scheduled in it.

Across the year

Southwest on MIA to MCI through the year

Jul–Sep 202525 flights—
Oct–Dec 202517 flights—
Jan–Mar 202664 flights67.2%
Apr–Jun 202676 flights59.2%

Scale runs 50% to 75%. Rows with fewer than 30 flights show a dash.

Monthly volumes are too low here to break the year into twelve reliable readings. What the twelve-month total says is 63.2% on time across 182 flights.

Split by quarter, Southwest on MIA to MCI logged 25 flights in Jul–Sep 2025, 17 flights in Oct–Dec 2025, 64 flights in Jan–Mar 2026 and 76 flights in Apr–Jun 2026. Fewer than three of those quarters carried the 30 completed flights this site needs before printing a rate, so the 63.2% annual figure is the one to use.

Across the week, Friday is the strongest day at 70.0% on time and Monday the weakest at 48.4%. 22 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 45% of the 4,789 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.

Late-arriving aircraft
45%
Carrier
36%
National Airspace System
16%
Extreme weather
3%

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 4,789 reported delay minutes here, that single category outweighs weather by 17 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 4,789 reported delay minutes.

The largest share of delay minutes, 36%, 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 1,706 of the 4,789 delay minutes reported here.

Cancellations are rare at 0.00%, below the national 1.81% and low enough to earn the plus on the grade. Almost no flights are 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. 12.1% 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 1,251 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 70.0% on time across 181 flights, 7 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 7 points of difference.

One caution: this is a thin sample. 182 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 MIA to MCI

Put together: treat all of this as provisional. 182 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 63.2% headline is the most reliable number on the page; the hour and month splits below it are built on a few dozen flights each. 182 completed flights over 12 months sit behind that.

Where to go next

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.

Key figures