Route reliability record
DAL→MDW
Dallas to Chicago
- Flights
- 2,154
- Period
- July 2025 to June 2026
- Distance
- 793 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, 7 points worse than the national rate of 77.6%. The late ones land about an hour behind schedule. That rests on 2,154 flights, with a median arrival 1 minutes late.
The national on-time rate over the same period is 77.6%, so this route runs 7 points behind the country as a whole. Across a thousand flights that is about 69 extra late arrivals.
Key figures
On time
70.7%
Arrivals under 15 minutes late, of 2,101 completed flights
Avg delay
56 min
Across delayed arrivals only, not all flights
Cancelled
1.90%
National rate is 1.81%
Best carrier
Southwest
70.7% on time across 2,154 flights
These figures cover 2,154 flights between July 2025 and June 2026. Beyond the headline rate, 9.0% 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 DAL 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 | 2,154 | 70.7% | 56 min | 1.90% | 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 38 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–8am440 flights92.1%
- 8am–11am362 flights77.7%
- 11am–2pm213 flights74.1%
- 2pm–5pm462 flights65.3%
- 5pm–8pm377 flights56.4%
- 8pm–5am300 flights54.2%
Scale runs 45% to 100%. Rows with fewer than 30 flights show a dash.
The 8pm–5am window is where this operation falls apart: 54.2% on time, against 92.1% 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 2pm–5pm window is the busiest, with 462 flights scheduled in it.
Across the year
When delays peak on this route
This route's year swings by 26 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.
June is the worst month at 56.4% on time, 26 points below February, the best at 82.1%. 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 202 flights.
Across the week, Tuesday is the strongest day at 78.1% on time and Thursday the weakest at 65.9%. 12 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 50% of the 35,000 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.
- 50%Late-arriving aircraft
- 30%Carrier
- 16%National Airspace System
- 4%Extreme weather
- 0%Security
50% 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 35,000 reported delay minutes here, that single category outweighs weather by 12 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 34,563 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 92.1% on time here.
Cancellations sit at 1.90% against a national 1.81%, which is ordinary. Diversions add another 0.56%.
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. 9.0% 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 793 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 77.5% on time across 2,153 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.
The sample behind these figures is 2,154 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. February runs 82.1% on time and June 56.4%, a swing of 26 points. If the dates move at all, move them out of June before you think about anything else. 2,101 completed flights over 12 months sit behind that.
Common questions
DAL to MDW questions
How often is DAL to MDW 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 29.3% of the 2,154 flights in this analysis, against 22.4% nationally. Delayed flights are late by about an hour on average.
How reliable is DAL to MDW compared with the rest of the country?
70.7% of flights arrive on time here against a national 77.6%, a difference of 7 points against it. That is worth a C on this site's grading scale.
What time of day has the fewest delays on DAL to MDW?
The 5am–8am departure window is the strongest at 92.1% on time. The 8pm–5am window is the weakest at 54.2%, 38 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 June delays on DAL to MDW?
June is the weakest month at 56.4% on time, compared with 82.1% in February. Across the year that is 26 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 DAL — the return legseparate record
- Dallas Love Field (DAL) delay statistics
- Chicago Midway International (MDW) delay statistics
- Southwest Airlines on-time record70.7%
- 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. DAL to MDW and MDW to DAL 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.