Route reliability record
HOU→MDW
Houston to Chicago
- Flights
- 1,834
- Period
- July 2025 to June 2026
- Distance
- 937 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, 5 points worse than the national rate of 77.6%. The late ones land about 50 minutes behind schedule. That rests on 1,834 HOU to MDW flights, with a median arrival 1 minute late.
Best time to fly HOU to MDW: a 5am–8am departure, ideally on a Tuesday. Flights in that window arrived on time 88.9% of the time and Tuesday flights 79.4%, against 72.7% for the route overall.
The national on-time rate over the same period is 77.6%, so this route runs 5 points behind the country as a whole. Across a thousand flights that is about 49 extra late arrivals.
Key figures
On time
72.7%
Arrivals under 15 minutes late, of 1,801 completed flights
Avg delay
50 min
Across delayed arrivals only, not all flights
Cancelled
1.09%
National rate is 1.81%
Best carrier
Southwest
72.7% on time across 1,834 flights
These figures cover 1,834 flights between July 2025 and June 2026. On-time means an arrival less than 15 minutes after the scheduled gate time, the same threshold the Department of Transportation uses in its own reports. Cancelled and diverted flights are excluded from the on-time rate and counted separately, which is why the cancellation column matters on its own.
Carrier by carrier
Which airline is most reliable on HOU 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 | 1,834 | 72.7% | 50 min | 1.09% | C |
Best ways to make this trip
The most reliable ways to fly Houston to Chicago
Every airline on this route and on the routes between nearby airports, ranked by how often a scheduled flight actually operated and arrived on time. 2 of the top 3 use a different airport at one end.
| Option | Airline | Success | On time | Cancelled | Best departure | Most punctual flight |
|---|---|---|---|---|---|---|
| 1. IAH → ORDHouston to Chicago | United Airlines | 77.7% | 78.2% | 0.60% | 5am–8am, Thu | UA 1617 08:23 |
| 2. HOU → MDWHouston to Chicago | Southwest Airlines | 71.9% | 72.7% | 1.09% | 5am–8am, Tue | — |
| 3. IAH → ORDHouston to Chicago | American Airlines | 64.7% | 67.1% | 3.51% | 5am–8am, Tue | — |
Success is the share of scheduled flights that operated and arrived less than 15 minutes late, so a cancelled flight counts against it. “(route)” means the best time comes from every carrier on the route rather than this airline alone.
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 28 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–8am408 flights88.9%
- 8am–11am202 flights83.2%
- 11am–2pm267 flights74.1%
- 2pm–5pm357 flights61.4%
- 5pm–8pm284 flights63.9%
- 8pm–5am316 flights64.4%
Scale runs 55% to 95%. Rows with fewer than 30 flights show a dash.
Book the early departure. Flights leaving between 5am–8am arrive on time 88.9% of the time, against 61.4% for the afternoon window. That is 28 points of difference for no extra money, and it comes from the same aircraft having had no earlier flight to fall behind on. The 5am–8am window is the busiest, with 408 flights scheduled in it.
Across the year
When delays peak on this route
This route's year swings by 38 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 50.6% on time, 38 points below September, the best at 88.9%. 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 187 flights.
Across the week, Tuesday is the strongest day at 79.4% on time and Sunday the weakest at 63.7%. 16 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 43% of the 25,000 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.
- 43%Late-arriving aircraft
- 35%Carrier
- 18%National Airspace System
- 4%Extreme weather
- 0%Security
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 25,000 reported delay minutes here, that single category outweighs weather by 10 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 24,756 reported delay minutes.
The largest share of delay minutes, 35%, falls under carrier control: crew scheduling, maintenance, fuelling, baggage. Unlike weather, that is a management outcome, and it is the category where the gap between two carriers on the same schedule is genuinely earned. It accounts for 8,600 of the 25,000 delay minutes reported here.
Cancellations sit at 1.09% against a national 1.81%, which is ordinary. Diversions add another 0.71%.
Connections and stage length
What a delay here actually costs
7.6% 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 50 minutes, which a normal layover absorbs.
The 937 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 runs 73.6% on time across 1,841 flights, within about a point of this direction. The two legs are scored separately because they usually differ; on this city pair they happen not to.
The sample behind these figures is 1,834 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.
Work out the risk of missing a connection in MDW after this flight
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 88.9% on time and June 50.6%, a swing of 38 points. If the dates move at all, move them out of June before you think about anything else. 1,801 completed flights over 12 months sit behind that.
Common questions
HOU to MDW questions
How often is HOU to MDW delayed?
Roughly one flight in four arrives at least 15 minutes late, which is the Department of Transportation's definition of a delayed arrival. That works out to 27.3% of the 1,834 flights in this analysis, against 22.4% nationally. Delayed flights are late by about 50 minutes on average.
How reliable is HOU to MDW compared with the rest of the country?
72.7% of flights arrive on time here against a national 77.6%, a difference of 5 points against it. That is worth a C on this site's grading scale.
What time of day has the fewest delays on HOU to MDW?
The 5am–8am departure window is the strongest at 88.9% on time. The 2pm–5pm window is the weakest at 61.4%, 28 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 HOU to MDW?
June is the weakest month at 50.6% on time, compared with 88.9% in September. Across the year that is 38 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 HOU — the return legseparate record
- William P. Hobby (HOU) delay statistics
- Chicago Midway International (MDW) delay statistics
- HOU to DAL, a related route80.9%
- ATL to MDW, a related route76.3%
- HOU to ATL, a related route79.8%
- Southwest Airlines on-time record72.7%
- 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. HOU to MDW and MDW to HOU are scored separately because they are separate operations, with different departure banks and different aircraft. Compare the return leg.
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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.