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DelayAtlas

Route reliability record

MDWDAL

Chicago to Dallas

Flights
2,153
Period
July 2025 to June 2026
Distance
793 mi
Carriers
1
BGRADE

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 2,153 flights, with a median arrival 5 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

77.5%

Arrivals under 15 minutes late, of 2,098 completed flights

Avg delay

58 min

Across delayed arrivals only, not all flights

Cancelled

2.04%

National rate is 1.81%

Best carrier

Southwest

77.5% on time across 2,153 flights

These figures cover 2,153 flights between July 2025 and June 2026. The median arrival is 5 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 MDW to DAL

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.

On-time performance by carrier on MDW to DAL
AirlineFlightsOn timeAvg delayCancelledGrade
Southwest Airlines2,15377.5%58 min2.04%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–8am462 flights92.5%
  • 8am–11am415 flights84.4%
  • 11am–2pm338 flights77.9%
  • 2pm–5pm286 flights72.9%
  • 5pm–8pm386 flights65.3%
  • 8pm–5am266 flights62.5%

Scale runs 55% to 100%. Rows with fewer than 30 flights show a dash.

The 8pm–5am window is where this operation falls apart: 62.5% 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 5am–8am 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 21 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.

On-time rate by calendar month85J85F81M80A74M64J69J80A80S81O81N74D
Darker means more delays. Figures are on-time percentages.February best, June worst

June is the worst month at 64.4% on time, 21 points below February, the best at 85.1%. 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 82.7% on time and Sunday the weakest at 70.0%. 13 points is a smaller lever than departure hour, but it is free.

On-time rate by day of the week79.7Mon82.7Tue81.1Wed77.5Thu76.3Fri74.1Sat70.0Sun
Monday: 79.7 percent on time. Tuesday: 82.7 percent on time. Wednesday: 81.1 percent on time. Thursday: 77.5 percent on time. Friday: 76.3 percent on time. Saturday: 74.1 percent on time. Sunday: 70.0 percent on time

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 27,000 reported delay minutes.

  • Late-arriving aircraft
    41%
  • Carrier
    34%
  • National Airspace System
    21%
  • Extreme weather
    4%
  • Security
    0%

41% 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 27,000 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 27,454 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 sit at 2.04% against a national 1.81%, which is ordinary. Diversions add another 0.51%.

Connections and stage length

What a delay here actually costs

6.4% 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 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 70.7% on time across 2,154 flights, 7 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 7 points of difference.

The sample behind these figures is 2,153 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 85.1% on time and June 64.4%, a swing of 21 points. If the dates move at all, move them out of June before you think about anything else. 2,098 completed flights over 12 months sit behind that.

Common questions

MDW to DAL questions

How often is MDW to DAL 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 22.5% of the 2,153 flights in this analysis, against 22.4% nationally. Delayed flights are late by about an hour on average.

How reliable is MDW to DAL compared with the rest of the country?

77.5% 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 MDW to DAL?

The 5am–8am departure window is the strongest at 92.5% on time. The 8pm–5am window is the weakest at 62.5%, 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 June delays on MDW to DAL?

June is the weakest month at 64.4% on time, compared with 85.1% in February. Across the year that is 21 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

Source: US DOT Bureau of Transportation Statistics, on-time performance data, July 2025 to June 2026. Updated monthly. How this data is collected.