Carrier route record
WNDTW→MDW
Southwest Airlines · Detroit to Chicago
- Flights
- 1,055
- Period
- July 2025 to June 2026
- Share of route
- 80%
- Carriers
- 2
Historical statistics for July 2025 to June 2026, not live status. For today’s flights, check with Southwest Airlines.
Southwest on DTW to MDW sits in the middle of the pack with a B. Close to three flights in four arrive on time by the DOT's definition, 2 points worse than the national rate of 77.6%. The late ones land about an hour behind schedule. That rests on 1,055 flights, with a median arrival 1 minute early.
The US average over the same twelve months is 77.6%, so there is little to separate Southwest on DTW to MDW from the country as a whole. The variation that matters here is internal: which carrier, and what time of day.
Key figures
On time
75.8%
Arrivals under 15 minutes late, of 1,033 completed flights
Avg delay
55 min
Across delayed arrivals only, not all flights
Cancelled
1.52%
National rate is 1.81%
Whole route
76.2%
Every carrier on DTW to MDW, 1,320 flights
These figures cover 1,055 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
Southwest against every carrier on DTW to MDW
Southwest flew 1,055 of the 1,320 flights on DTW to MDW, most of the route. Its 75.8% on time is about level with the route as a whole at 76.2%. Ranked by on-time rate it is last of two carriers on the route, where the range runs from SkyWest at 77.7% to Southwest at 75.8%. One of those carriers flew fewer than 365 flights here, so treat their positions as rough.
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 |
|---|---|---|---|---|---|
| SkyWest Airlinesthin sample | 265 | 77.7% | 64 min | 0.38% | B+ |
| Southwest Airlines (this page) | 1,055 | 75.8% | 55 min | 1.52% | B |
Departure window
When Southwest runs best on this route
Departure time matters more here than the choice of carrier. The gap between the best and worst window is 31 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–8am245 flights84.5%
- 8am–11am119 flights80.0%
- 11am–2pm269 flights79.1%
- 2pm–5pm74 flights88.9%
- 5pm–8pm199 flights66.7%
- 8pm–5am149 flights57.9%
Scale runs 50% to 95%. Rows with fewer than 30 flights show a dash.
The 8pm–5am window is where this operation falls apart: 57.9% on time, against 88.9% for the 2pm–5pm 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 269 flights scheduled in it.
Across the year
Southwest on DTW to MDW through the year
June is the worst month at 55.3% on time, 32 points below October, the best at 87.1%. 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. August was the busiest month here, with 93 flights.
Across the week, Friday is the strongest day at 79.6% on time and Thursday the weakest at 73.7%. 6 points is a smaller lever than departure hour, but it is free.
Delay causes
Why Southwest runs late on this route
One category carries most of the weight here. Late-arriving aircraft accounts for 44% of the 14,000 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.
- 44%Late-arriving aircraft
- 29%National Airspace System
- 25%Carrier
- 1%Extreme weather
- 0%Security
44% 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 14,000 reported delay minutes here, that single category outweighs weather by 30 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 13,514 reported delay minutes.
Cancellations sit at 1.52% against a national 1.81%, which is ordinary. Diversions add another 0.57%.
Connections and stage length
What a delay here costs
5.8% 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 an hour, which a normal layover absorbs.
At 228 miles this is a short hop, and stage length matters more than it looks. A flight this short spends under two hours in the air, which leaves almost nothing to claw back a late pushback with. Delay here is decided on the ground, in the turn, which is why the 2pm–5pm window matters as much as it does.
The return leg runs 73.6% on time across 1,053 flights, within 2 points of this direction. The two legs are scored separately because they usually differ; on this city pair they happen not to.
One caution: this is a thin sample. 1,055 flights over twelve months is enough to clear this site's floor but not enough to pin the rate down tightly, and a single bad week moves it by more than a point. Treat the grade as a rough reading.
What to do with this
Booking Southwest on DTW to MDW
Put together: treat all of this as provisional. 1,055 flights over twelve months is enough to clear this site's floor and not enough to be confident to better than a couple of points. The 75.8% headline is the most reliable number on the page; the hour and month splits below it are built on a few dozen flights each. 1,033 completed flights over 12 months sit behind that.
Related
Where to go next
- DTW to MDW, every carrier
- Southwest on MDW to DTW, the return leg
- SkyWest Airlines on DTW to MDW77.7%
- Southwest Airlines network-wide record
- Detroit Metropolitan Wayne County (DTW) delay statistics
- Chicago Midway International (MDW) delay statistics
- Why the first flight of the morning is statistically safest
- The best time of day to fly, according to 7.04 million flight records
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.