Carrier route record
WNDCA→MCI
Southwest Airlines · Washington to Kansas City
- Flights
- 999
- Period
- July 2025 to June 2026
- Share of route
- 52%
- Carriers
- 5
Historical statistics for July 2025 to June 2026, not live status. For today’s flights, check with Southwest Airlines.
Southwest on DCA to MCI sits in the middle of the pack with a C. About seven flights in ten arrive on time by the DOT's definition, 5 points worse than the national rate of 77.6%. The late ones land about an hour behind schedule. That rests on 999 flights, with a median arrival 2 minutes early.
The national on-time rate over the same period is 77.6%, so Southwest on DCA to MCI runs 5 points behind the country as a whole. Across a thousand flights that is about 49 extra late arrivals.
Key figures
On time
72.7%
Arrivals under 15 minutes late, of 979 completed flights
Avg delay
65 min
Across delayed arrivals only, not all flights
Cancelled
1.80%
National rate is 1.81%
Whole route
71.7%
Every carrier on DCA to MCI, 1,927 flights
These figures cover 999 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 DCA to MCI
Southwest flew 999 of the 1,927 flights on DCA to MCI, most of the route. Its 72.7% on time is about level with the route as a whole at 71.7%. Ranked by on-time rate it is number three of five carriers on the route, where the range runs from American at 84.0% to PSA at 68.2%. Three 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 |
|---|---|---|---|---|---|
| American Airlinesthin sample | 25 | 84.0% | 42 min | 0.00% | B+ |
| Republic Airwaysthin sample | 152 | 75.5% | 44 min | 0.66% | B+ |
| Southwest Airlines (this page) | 999 | 72.7% | 65 min | 1.80% | C |
| Envoy Airthin sample | 168 | 71.6% | 64 min | 3.57% | C− |
| PSA Airlines | 583 | 68.2% | 69 min | 6.17% | 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 43 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–8am332 flights92.0%
- 8am–11am1 flights—
- 11am–2pm238 flights80.0%
- 2pm–5pm193 flights52.1%
- 5pm–8pm146 flights58.3%
- 8pm–5am89 flights48.8%
Scale runs 40% to 95%. Rows with fewer than 30 flights show a dash.
The 8pm–5am window is where this operation falls apart: 48.8% on time, against 92.0% 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. The 5am–8am window is the busiest, with 332 flights scheduled in it.
Across the year
Southwest on DCA to MCI through the year
June is the worst month at 54.4% on time, 36 points below January, the best at 89.9%. 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. December was the busiest month here, with 89 flights.
Across the week, Tuesday is the strongest day at 79.6% on time and Saturday the weakest at 66.1%. 14 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 62% of the 17,000 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.
- 62%Late-arriving aircraft
- 26%Carrier
- 11%National Airspace System
- 1%Extreme weather
- 0%Security
62% 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 17,000 reported delay minutes here, that single category outweighs weather by 62 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 17,237 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 92.0% on time here.
Cancellations sit at 1.80% against a national 1.81%, which is ordinary. Diversions add another 0.20%.
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 949 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 runs 73.1% on time across 999 flights, within half a point of this direction. The two legs are scored separately because they usually differ; on this city pair they happen not to.
One caution: this is a thin sample. 999 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 DCA to MCI
Put together: treat all of this as provisional. 999 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 72.7% headline is the most reliable number on the page; the hour and month splits below it are built on a few dozen flights each. 979 completed flights over 12 months sit behind that.
Related
Where to go next
- DCA to MCI, every carrier
- Southwest on MCI to DCA, the return leg
- Republic Airways on DCA to MCI75.5%
- Envoy Air on DCA to MCI71.6%
- PSA Airlines on DCA to MCI68.2%
- Southwest Airlines network-wide record
- Ronald Reagan Washington National (DCA) delay statistics
- Kansas City International (MCI) delay statistics
- Why the first flight of the morning is statistically safest
- How often a connection fails at the major US hubs
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.