Carrier route record

WNSTL→MSP

Southwest Airlines · St. Louis to Minneapolis

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 STL to MSP lands a B+, 2 points worse than the national rate of 77.6%. About one flight in four 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 1 minute early.

The US average over the same twelve months is 77.6%, 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.

On time

76.0%

Arrivals under 15 minutes late, of 649 completed flights

Avg delay

53 min

Across delayed arrivals only, not all flights

Cancelled

0.31%

National rate is 1.81%

Whole route

79.8%

Every carrier on STL to MSP, 1,896 flights

These figures cover 651 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 STL to MSP

Southwest flew 651 of the 1,896 flights on STL to MSP, about 34% of it. Its 76.0% on time is 4 points worse than the route as a whole, which runs 79.8%. Ranked by on-time rate it is number two of three carriers on the route, where the range runs from Delta at 84.1% to SkyWest at 75.9%. 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.

On-time performance by carrier on STL to MSP
Airline	Flights	On time	Avg delay	Cancelled	Grade
Delta Air Lines	886	84.1%	90 min	1.13%	B
Southwest Airlines (this page)	651	76.0%	53 min	0.31%	B+
SkyWest Airlinesthin sample	359	75.9%	106 min	1.67%	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 27 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–8am1 flights—
8am–11am271 flights90.4%
11am–2pm25 flights—
2pm–5pm23 flights—
5pm–8pm13 flights—
8pm–5am318 flights63.0%

Scale runs 55% to 95%. Rows with fewer than 30 flights show a dash.

The 8pm–5am window is where this operation falls apart: 63.0% on time, against 90.4% 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 318 flights scheduled in it.

Across the year

Southwest on STL to MSP through the year

Darker means more delays. Figures are on-time percentages.August best, December worst

December is the weak month at 62.1% on time, against 89.3% in August. 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 61 flights.

Across the week, Wednesday is the strongest day at 86.3% on time and Sunday the weakest at 56.3%. 30 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 61% of the 8,286 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.

Late-arriving aircraft
61%
Carrier
22%
National Airspace System
14%
Extreme weather
2%
Security
0%

61% 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 8,286 reported delay minutes here, that single category outweighs weather by 31 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 8,286 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 90.4% 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

6.0% 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 80.2% on time across 651 flights, 4 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 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 STL to MSP

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 76.0% headline is the most reliable number on the page; the hour and month splits below it are built on a few dozen flights each. 649 completed flights over 12 months sit behind that.

Where to go next

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.

Key figures