Route reliability record
DCA→MDW
Washington to Chicago
- Flights
- 2,104
- Period
- July 2025 to June 2026
- Distance
- 601 mi
- Carriers
- 1
This route lands a B, level with the national rate of 77.6%. Roughly one flight in four arrive 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 2,104 flights, with a median arrival 3 minutes early.
The US average over the same twelve months is 77.6%, so there is little to separate this route from the country as a whole. The variation that matters here is internal: which carrier, and what time of day.
Key figures
On time
77.2%
Arrivals under 15 minutes late, of 2,032 completed flights
Avg delay
62 min
Across delayed arrivals only, not all flights
Cancelled
2.76%
National rate is 1.81%
Best carrier
Southwest
77.2% on time across 2,104 flights
These figures cover 2,104 flights between July 2025 and June 2026. The median arrival is 3 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
Which airline is most reliable on DCA to MDW
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 | 77.2% | 62 min | 2.76% | B |
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 30 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–8am319 flights92.5%
- 8am–11am411 flights88.3%
- 11am–2pm365 flights79.9%
- 2pm–5pm373 flights70.5%
- 5pm–8pm334 flights62.7%
- 8pm–5am302 flights66.3%
Scale runs 55% to 100%. Rows with fewer than 30 flights show a dash.
The 5pm–8pm window is where this operation falls apart: 62.7% on time, against 92.5% 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 8am–11am window is the busiest, with 411 flights scheduled in it.
Across the year
When delays peak on this route
This route's year swings by 25 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 88.1% 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, Saturday is the strongest day at 84.9% on time and Friday the weakest at 71.2%. 14 points is a smaller lever than departure hour, but it is free.
Delay causes
Why this route gets delayed
One category carries most of the weight here. Late-arriving aircraft accounts for 58% of the 29,000 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.
- 58%Late-arriving aircraft
- 24%Carrier
- 13%National Airspace System
- 5%Extreme weather
58% 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 29,000 reported delay minutes here, that single category outweighs weather by 11 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 28,802 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 92.5% on time here.
Cancellations run at 2.76%, against 1.81% nationally. That is roughly one flight in 40 cancelled outright. A cancelled flight is invisible in every on-time figure on this page, so the punctuality numbers above describe only the flights that actually operated.
Connections and stage length
What a delay here actually costs
7.9% 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 are the about an hour kind, which a normal layover absorbs.
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 69.4% on time across 2,104 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.
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 88.1% on time and March 63.5%, a swing of 25 points. If the dates move at all, move them out of March before you think about anything else. 2,032 completed flights over 12 months sit behind that.
Common questions
DCA to MDW questions
How often is DCA to MDW delayed?
Roughly one flight in four arrive at least 15 minutes late, which is the Department of Transportation's definition of a delayed arrival. That works out to 22.8% 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 DCA to MDW compared with the rest of the country?
77.2% of flights arrive on time here against a national 77.6%, a difference of half a point against it. That is worth a B on this site's grading scale.
What time of day has the fewest delays on DCA to MDW?
The 5am–8am departure window is the strongest at 92.5% on time. The 5pm–8pm window is the weakest at 62.7%, 30 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 DCA to MDW?
March is the weakest month at 63.5% on time, compared with 88.1% in September. Across the year that is 25 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
- MDW to DCA — the return legseparate record
- Ronald Reagan Washington National (DCA) delay statistics
- Chicago Midway International (MDW) delay statistics
- Southwest Airlines on-time record77.2%
- Why the first flight of the morning is statistically safest
- What a cancellation rate actually tells you (and what it hides)
Direction matters. DCA to MDW and MDW to DCA 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.