Carrier route record
WNDCA→MKE
Southwest Airlines · Washington to Milwaukee
- Flights
- 683
- Period
- July 2025 to June 2026
- Share of route
- 51%
- Carriers
- 3
Historical statistics for July 2025 to June 2026, not live status. For today’s flights, check with Southwest Airlines.
Southwest on DCA to MKE lands a B, 5 points better than the national rate of 77.6%. About one flight in six arrives 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 683 flights, with a median arrival 7 minutes early.
Set against the rest of the country, Southwest's DCA to MKE 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 673 completed flights
Avg delay
64 min
Across delayed arrivals only, not all flights
Cancelled
1.46%
National rate is 1.81%
Whole route
77.3%
Every carrier on DCA to MKE, 1,349 flights
These figures cover 683 flights between July 2025 and June 2026. The median arrival is 7 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
Southwest against every carrier on DCA to MKE
Southwest flew 683 of the 1,349 flights on DCA to MKE, most of the route. Its 82.8% on time is 6 points better than the route as a whole, which runs 77.3%. Ranked by on-time rate it is number two of three carriers on the route, where the range runs from Republic at 83.3% to PSA at 71.3%. One 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 |
|---|---|---|---|---|---|
| Republic Airwaysthin sample | 7 | 83.3% | 81 min | 14.29% | B− |
| Southwest Airlines (this page) | 683 | 82.8% | 64 min | 1.46% | B |
| PSA Airlines | 659 | 71.3% | 77 min | 7.13% | 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 25 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–8am178 flights95.4%
- 8am–11am139 flights94.2%
- 11am–2pm26 flights—
- 2pm–5pm339 flights70.7%
- 5pm–8pm1 flights—
- 8pm–5am—
Scale runs 60% to 100%. Rows with fewer than 30 flights show a dash.
Book the early departure. Flights leaving between 5am–8am arrive on time 95.4% of the time, against 70.7% for the afternoon window. That is 25 points of difference for no extra money, and it comes from the same aircraft having had no earlier flight to fall behind on. The 2pm–5pm window is the busiest, with 339 flights scheduled in it.
Across the year
Southwest on DCA to MKE through the year
July is the worst month at 68.9% on time, 26 points below January, the best at 94.4%. 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. July was the busiest month here, with 62 flights.
Across the week, Tuesday is the strongest day at 90.5% on time and Thursday the weakest at 75.0%. 16 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 43% of the 7,381 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.
- 43%Late-arriving aircraft
- 29%Carrier
- 18%National Airspace System
- 10%Extreme weather
43% 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 7,381 reported delay minutes here, that single category outweighs weather by 4 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 7,381 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 95.4% on time here.
Cancellations sit at 1.46% against a national 1.81%, which is ordinary. Diversions add another 0.00%.
Connections and stage length
What a delay here costs
6.2% 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 last about an hour, which a normal layover absorbs.
The 634 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 75.1% on time across 683 flights, 8 points below 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 8 points of difference.
One caution: this is a thin sample. 683 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 MKE
Put together: treat all of this as provisional. 683 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 82.8% headline is the most reliable number on the page; the hour and month splits below it are built on a few dozen flights each. 673 completed flights over 12 months sit behind that.
Related
Where to go next
- DCA to MKE, every carrier
- Southwest on MKE to DCA, the return leg
- PSA Airlines on DCA to MKE71.3%
- Southwest Airlines network-wide record
- Ronald Reagan Washington National (DCA) 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.