Carrier route record
WNMDW→DTW
Southwest Airlines · Chicago to Detroit
- Flights
- 1,046
- Period
- September 2025 to August 2026
- Share of route
- 88%
- Carriers
- 2
Historical statistics for September 2025 to August 2026, not live status. For today’s flights, check with Southwest Airlines.
Southwest on MDW to DTW sits in the middle of the pack with a C. Close to three flights in four arrive on time by the DOT's definition, 3 points worse than the national rate of 77.3%. The late ones land about 55 minutes behind schedule. That rests on 1,046 flights, with a median arrival 2 minutes early.
The US average over the same twelve months is 77.3%, so there is little to separate Southwest on MDW to DTW from the country as a whole. The variation that matters here is internal: which carrier, and what time of day.
Key figures
On time
73.9%
Arrivals under 15 minutes late, of 1,026 completed flights
Avg delay
55 min
Across delayed arrivals only, not all flights
Cancelled
1.82%
National rate is 1.89%
Whole route
75.9%
Every carrier on MDW to DTW, 1,183 flights
These figures cover 1,046 flights between September 2025 and August 2026. The median arrival is 2 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.
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Carrier by carrier
Southwest against every carrier on MDW to DTW
Southwest flew 1,046 of the 1,183 flights on MDW to DTW, most of the route. Its 73.9% on time is 2 points worse than the route as a whole, which runs 75.9%. Ranked by on-time rate it is last of two carriers on the route, where the range runs from SkyWest at 91.2% to Southwest at 73.9%. 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 | 137 | 91.2% | 64 min | 0.00% | A+ |
| Southwest Airlines (this page) | 1,046 | 73.9% | 55 min | 1.82% | C |
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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.
- 5am–8am62 flights87.1%
- 8am–11am290 flights88.5%
- 11am–2pm198 flights72.5%
- 2pm–5pm117 flights72.6%
- 5pm–8pm256 flights58.0%
- 8pm–5am123 flights68.0%
Scale runs 50% to 95%.
The 5pm–8pm window is where this operation falls apart: 58.0% on time, against 88.5% for the 8am–11am 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 290 flights scheduled in it.
Across the year
Southwest on MDW to DTW through the year
June is the worst month at 57.6% on time, 31 points below November, the best at 88.5%. 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. October was the busiest month here, with 93 flights.
Across the week, Wednesday is the strongest day at 78.1% on time and Sunday the weakest at 70.1%, a spread of 8 points.
Arrival by arrival
How late Southwest on MDW to DTW runs when it is late
The 268 late arrivals split 106 under half an hour, 81 between 30 and 60 minutes, and 81 an hour or more.
- 15+ min early153 flights14.9%
- Within 15 min605 flights59.0%
- 15–29 min late106 flights10.3%
- 30–59 min late81 flights7.9%
- 1–2 hours late54 flights5.3%
- 2+ hours late27 flights2.6%
Scale runs 0% to 100%.
Share of 1,026 completed flights by arrival against schedule.
74 of 306 late departures made up the time and arrived on time, 24% of them. 36 flights left on time and still arrived late.
The worst days
Worst days for Southwest on MDW to DTW
The latest arrival of the period was on 10 March 2026, 7 hours 50 minutes behind schedule; most of its delay minutes were filed as a late-arriving aircraft. The same cause led on five of the five worst days.
| Date | Arrived late by | Largest filed cause |
|---|---|---|
| 10 March 2026 | 7 hours 50 minutes | Late-arriving aircraft |
| 12 August 2026 | 4 hours 54 minutes | Late-arriving aircraft |
| 18 May 2026 | 4 hours 41 minutes | Late-arriving aircraft |
| 9 August 2026 | 4 hours 37 minutes | Late-arriving aircraft |
| 14 April 2026 | 3 hours 55 minutes | Late-arriving aircraft |
Delay causes
Why Southwest runs late on this route
Late-arriving aircraft accounts for 58% of the 15,000 delay minutes carriers reported here, and the remaining four split what is left.
- 58%Late-arriving aircraft
- 26%Carrier
- 13%National Airspace System
- 2%Extreme weather
- 1%Security
58% of delay minutes trace back to a late-arriving aircraft, meaning the plane was already behind before it got here. Across 15,000 reported delay minutes here, that single category outweighs weather by 26 to one. The split is drawn from 14,652 reported delay minutes.
The practical consequence: the 8am–11am departure is the one that starts clean. Its aircraft has no earlier leg to be late from, which is exactly why that window shows 88.5% on time here.
Cancellations sit at 1.82% against a national 1.89%, which is ordinary. Diversions add another 0.10%.
Connections and stage length
What a delay here costs
7.9% of arrivals land an hour or more late, close to the national 8.3%, so a 60 to 75 minute layover is reasonable here while anything under 45 minutes is a bet. Most delays on this route last about 55 minutes, 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 8am–11am window matters as much as it does.
The return leg runs 72.4% on time across 1,047 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. 1,046 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 MDW to DTW
Put together: treat all of this as provisional. 1,046 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 73.9% headline is the most reliable number on the page; the hour and month splits below it are built on a few dozen flights each. 1,026 completed flights over 12 months sit behind that.
Related
Where to go next
- MDW to DTW, every carrier
- Southwest on DTW to MDW, the return leg
- SkyWest Airlines on MDW to DTW91.2%
- Southwest Airlines network-wide record
- Chicago Midway International (MDW) delay statistics
- Detroit Metropolitan Wayne County (DTW) delay statistics
- Why the first flight of the morning is statistically safest
- The best time of day to fly, according to 7.05 million flight records
Source: US DOT Bureau of Transportation Statistics, on-time performance data, September 2025 to August 2026. Last updated ; recomputed monthly. How this data is collected.