Carrier route record
WNSTL→MSP
Southwest Airlines · St. Louis to Minneapolis
- Flights
- 657
- Period
- September 2025 to August 2026
- Share of route
- 33%
- Carriers
- 3
Historical statistics for September 2025 to August 2026, not live status. For today’s flights, check with Southwest Airlines.
Southwest on STL to MSP 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 roughly 55 minutes behind schedule. That rests on 657 flights. The strongest carrier on the route with a full sample, Delta Air Lines, flew 906 at 85.0% on time.
The US average over the same twelve months is 77.3%, so there is little to separate Southwest on STL to MSP from the country as a whole. The variation that matters here is internal: which carrier, and what time of day.
Key figures
On time
74.5%
Arrivals under 15 minutes late, of 655 completed flights
Avg delay
53 min
Across delayed arrivals only, not all flights
Cancelled
0.30%
National rate is 1.89%
Whole route
79.4%
Every carrier on STL to MSP, 1,962 flights
These figures cover 657 flights between September 2025 and August 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.
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Carrier by carrier
Southwest against every carrier on STL to MSP
Southwest flew 657 of the 1,962 flights on STL to MSP, about 33% of it. Its 74.5% on time is 5 points worse than the route as a whole, which runs 79.4%. Ranked by on-time rate it is last of three carriers on the route, where the range runs from Delta at 85.0% to Southwest at 74.5%.
The choice of carrier is not cosmetic here. Delta Air Lines arrives on time 85.0% of the time; SkyWest Airlines manages 74.6%. Sample sizes sit next to every figure, because a two-point gap across 399 flights means less than a ten-point one.
| Airline | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| Delta Air Lines | 906 | 85.0% | 86 min | 1.10% | A |
| SkyWest Airlines | 399 | 74.6% | 98 min | 1.50% | C |
| Southwest Airlines (this page) | 657 | 74.5% | 53 min | 0.30% | C+ |
Delta leads SkyWest by 10 points. Real, but small enough that a better departure time on the weaker carrier can outweigh it.
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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 28 points, against 10 points between the best and worst carrier.
- 5am–8am1 flights—
- 8am–11am291 flights89.7%
- 11am–2pm9 flights—
- 2pm–5pm19 flights—
- 5pm–8pm13 flights—
- 8pm–5am324 flights61.5%
Scale runs 55% to 95%. Rows with fewer than 30 flights show a dash.
The 8pm–5am window is where this operation falls apart: 61.5% on time, against 89.7% 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 8pm–5am window is the busiest, with 324 flights scheduled in it.
Across the year
Southwest on STL to MSP through the year
December is the weak month at 62.1% on time, against 87.5% in January. Winter delays cluster: a single storm system can account for most of a month's shortfall, so an average December hides both very good weeks and genuinely unflyable days. July was the busiest month here, with 62 flights.
Across the week, Tuesday is the strongest day at 84.2% on time and Sunday the weakest at 59.6%, a spread of 25 points.
Arrival by arrival
How late Southwest on STL to MSP runs when it is late
The 167 late arrivals split 69 under half an hour, 55 between 30 and 60 minutes, and 43 an hour or more.
- 15+ min early75 flights11.5%
- Within 15 min413 flights63.1%
- 15–29 min late69 flights10.5%
- 30–59 min late55 flights8.4%
- 1–2 hours late28 flights4.3%
- 2+ hours late15 flights2.3%
Scale runs 0% to 100%.
Share of 655 completed flights by arrival against schedule.
33 of 177 late departures made up the time and arrived on time, 19% of them. 23 flights left on time and still arrived late.
The worst days
Worst days for Southwest on STL to MSP
The latest arrival of the period was on 27 July 2026, 4 hours 53 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 |
|---|---|---|
| 27 July 2026 | 4 hours 53 minutes | Late-arriving aircraft |
| 27 June 2026 | 4 hours 20 minutes | Late-arriving aircraft |
| 16 March 2026 | 3 hours 41 minutes | Late-arriving aircraft |
| 18 July 2026 | 3 hours 23 minutes | Late-arriving aircraft |
| 1 June 2026 | 3 hours 18 minutes | Late-arriving aircraft |
Delay causes
Why Southwest runs late on this route
Late-arriving aircraft accounts for 65% of the 8,866 delay minutes carriers reported here, and the remaining four split what is left.
- 65%Late-arriving aircraft
- 22%Carrier
- 11%National Airspace System
- 2%Extreme weather
- 0%Security
65% of delay minutes trace back to a late-arriving aircraft, meaning the plane was already behind before it got here. Across 8,866 reported delay minutes here, that single category outweighs weather by 30 to one. The split is drawn from 8,866 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 89.7% on time here.
Cancellations are rare at 0.30%, below the national 1.89% and low enough to earn the plus on the grade. Roughly one flight in 100 is called off; the risk here is arriving late, not not arriving.
Connections and stage length
What a delay here costs
6.6% 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 roughly 55 minutes, which a normal layover absorbs.
At 448 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 is a different operation and performs like one: it runs 81.2% on time across 653 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.
One caution: this is a thin sample. 657 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 STL to MSP
Put together: treat all of this as provisional. 657 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 74.5% headline is the most reliable number on the page; the hour and month splits below it are built on a few dozen flights each. 655 completed flights over 12 months sit behind that.
Related
Where to go next
- STL to MSP, every carrier
- Southwest on MSP to STL, the return leg
- Delta Air Lines on STL to MSP85.0%
- SkyWest Airlines on STL to MSP74.6%
- Southwest Airlines network-wide record
- St. Louis Lambert International (STL) delay statistics
- Minneapolis-St Paul International (MSP) delay statistics
- Same route, different airline: where the carrier you pick matters most
- Why the first flight of the morning is statistically safest
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.