Carrier route record
WNMSP→STL
Southwest Airlines · Minneapolis to St. Louis
- Flights
- 651
- Period
- July 2025 to June 2026
- Share of route
- 34%
- Carriers
- 3
Historical statistics for July 2025 to June 2026, not live status. For today’s flights, check with Southwest Airlines.
Southwest on MSP to STL lands a B+, 3 points better than the national rate of 77.6%. About one flight in five arrives 15 minutes late or worse, and those flights are late by roughly 55 minutes on average. That is a workable record, not a spotless one. That rests on 651 flights, with a median arrival 7 minutes early.
The US average over the same twelve months is 77.6%, so there is little to separate Southwest on MSP to STL from the country as a whole. The variation that matters here is internal: which carrier, and what time of day.
Key figures
On time
80.2%
Arrivals under 15 minutes late, of 646 completed flights
Avg delay
53 min
Across delayed arrivals only, not all flights
Cancelled
0.31%
National rate is 1.81%
Whole route
79.5%
Every carrier on MSP to STL, 1,896 flights
These figures cover 651 flights between July 2025 and June 2026. The median arrival is 7 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
Southwest against every carrier on MSP to STL
Southwest flew 651 of the 1,896 flights on MSP to STL, about 34% of it. Its 80.2% on time is about level with the route as a whole at 79.5%. Ranked by on-time rate it is first of three carriers on the route, where the range runs from Southwest at 80.2% to SkyWest at 78.2%. 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 |
|---|---|---|---|---|---|
| Southwest Airlines (this page) | 651 | 80.2% | 53 min | 0.31% | B+ |
| Delta Air Lines | 886 | 79.5% | 68 min | 1.24% | B |
| SkyWest Airlinesthin sample | 359 | 78.2% | 93 min | 1.39% | 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 38 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–8am255 flights96.1%
- 8am–11am89 flights96.6%
- 11am–2pm21 flights—
- 2pm–5pm127 flights63.5%
- 5pm–8pm137 flights58.1%
- 8pm–5am22 flights—
Scale runs 50% to 100%. Rows with fewer than 30 flights show a dash.
The 5pm–8pm window is where this operation falls apart: 58.1% on time, against 96.6% 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 5am–8am window is the busiest, with 255 flights scheduled in it.
Across the year
Southwest on MSP to STL through the year
Delays peak in September, when the on-time rate falls to 69.6%. January is the strongest month at 92.1%. Moving a flexible trip across that boundary buys 23 points. July was the busiest month here, with 61 flights.
Across the week, Saturday is the strongest day at 89.7% on time and Tuesday the weakest at 75.5%. 14 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 60% of the 6,819 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.
- 60%Late-arriving aircraft
- 31%Carrier
- 8%National Airspace System
- 1%Extreme weather
60% 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 6,819 reported delay minutes here, that single category outweighs weather by 60 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 6,819 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 96.6% on time here.
Cancellations are rare at 0.31%, below the national 1.81% 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
5.6% 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 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 76.0% on time across 651 flights, 4 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 4 points of difference.
One caution: this is a thin sample. 651 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 MSP to STL
Put together: treat all of this as provisional. 651 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 80.2% headline is the most reliable number on the page; the hour and month splits below it are built on a few dozen flights each. 646 completed flights over 12 months sit behind that.
Related
Where to go next
- MSP to STL, every carrier
- Southwest on STL to MSP, the return leg
- Delta Air Lines on MSP to STL79.5%
- SkyWest Airlines on MSP to STL78.2%
- Southwest Airlines network-wide record
- Minneapolis-St Paul International (MSP) delay statistics
- St. Louis Lambert International (STL) 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.