Route reliability record
MDW→DCA
Chicago to Washington
- Flights
- 2,104
- Period
- July 2025 to June 2026
- Distance
- 601 mi
- Carriers
- 1
This route sits in the middle of the pack with a C. About seven flights in ten arrive on time by the DOT's definition, 8 points worse than the national rate of 77.6%. The late ones land about an hour behind schedule. That rests on 2,104 flights, with a median arrival 1 minutes early.
The national on-time rate over the same period is 77.6%, so this route runs 8 points behind the country as a whole. Across a thousand flights that is about 82 extra late arrivals.
Key figures
On time
69.4%
Arrivals under 15 minutes late, of 2,048 completed flights
Avg delay
59 min
Across delayed arrivals only, not all flights
Cancelled
2.14%
National rate is 1.81%
Best carrier
Southwest
69.4% on time across 2,104 flights
These figures cover 2,104 flights between July 2025 and June 2026. Beyond the headline rate, 9.7% 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
Which airline is most reliable on MDW to DCA
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 |
|---|---|---|---|---|---|
| Southwest Airlines | 2,104 | 69.4% | 59 min | 2.14% | C |
Departure window
The best time of day to leave
Departure time matters more here than the choice of carrier. The gap between the best and worst window is 36 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–8am349 flights90.4%
- 8am–11am368 flights86.5%
- 11am–2pm447 flights66.2%
- 2pm–5pm314 flights56.8%
- 5pm–8pm348 flights54.2%
- 8pm–5am278 flights57.7%
Scale runs 45% to 95%. Rows with fewer than 30 flights show a dash.
The 5pm–8pm window is where this operation falls apart: 54.2% on time, against 90.4% 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 11am–2pm window is the busiest, with 447 flights scheduled in it.
Across the year
When delays peak on this route
This route's year swings by 17 points from best month to worst, which is wide. An annual average tells you very little about the week you are actually flying, so read the strip rather than the headline if your dates are fixed.
September is the best month on the calendar at 78.4% on time. Shoulder season thins the schedule and takes the summer weather with it, and the operation gets its margin back. March was the busiest month here, with 181 flights.
Across the week, Tuesday is the strongest day at 76.1% on time and Sunday the weakest at 62.4%. 14 points is a smaller lever than departure hour, but it is free.
Delay causes
Why this route gets delayed
Carriers report a reason for every delay minute they cause, in five DOT categories. The split below is by minutes, not by number of flights, so a handful of very long weather delays weighs as much as many short ones. It covers 37,000 reported delay minutes.
- 39%National Airspace System
- 35%Late-arriving aircraft
- 23%Carrier
- 2%Extreme weather
- 0%Security
35% 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 37,000 reported delay minutes here, that single category outweighs weather by 16 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 36,623 reported delay minutes.
39% of delay minutes are charged to the National Airspace System: air traffic volume, runway configuration, ground stops. No carrier can price its way out of that, which is why airport choice moves the number here more than carrier choice does. That is 14,000 minutes out of 37,000, against a national NAS share of 21%.
Cancellations sit at 2.14% against a national 1.81%, which is ordinary. Diversions add another 0.52%.
Connections and stage length
What a delay here actually costs
For anyone connecting, the number to weigh is not the on-time rate but the tail behind it. 9.7% 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 601 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 77.2% on time across 2,104 flights, 8 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 8 points of difference.
The sample behind these figures is 2,104 flights, enough that the headline rate is stable to within roughly a point. The hour-block and month splits divide that further, so read the thinner bars with more caution than the headline.
What to do with this
Booking this route
Put together: the calendar is the biggest lever here, not the carrier or the hour. September runs 78.4% on time and March 61.5%, a swing of 17 points. If the dates move at all, move them out of March before you think about anything else. 2,048 completed flights over 12 months sit behind that.
Common questions
MDW to DCA questions
How often is MDW to DCA delayed?
Roughly one flight in three arrive at least 15 minutes late, which is the Department of Transportation's definition of a delayed arrival. That works out to 30.6% of the 2,104 flights in this analysis, against 22.4% nationally. Delayed flights are late by about an hour on average.
How reliable is MDW to DCA compared with the rest of the country?
69.4% of flights arrive on time here against a national 77.6%, a difference of 8 points against it. That is worth a C on this site's grading scale.
What time of day has the fewest delays on MDW to DCA?
The 5am–8am departure window is the strongest at 90.4% on time. The 5pm–8pm window is the weakest at 54.2%, 36 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 March delays on MDW to DCA?
March is the weakest month at 61.5% on time, compared with 78.4% in September. Across the year that is 17 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
- DCA to MDW — the return legseparate record
- Chicago Midway International (MDW) delay statistics
- Ronald Reagan Washington National (DCA) delay statistics
- Southwest Airlines on-time record69.4%
- Why the first flight of the morning is statistically safest
- The best time of day to fly, according to 7.04 million flight records
Direction matters. MDW to DCA and DCA to MDW are scored separately because they are separate operations, with different departure banks and different aircraft. Compare the return leg.
Source: US DOT Bureau of Transportation Statistics, on-time performance data, July 2025 to June 2026. Updated monthly. How this data is collected.