Carrier route record
WNBWI→MSP
Southwest Airlines · Baltimore to Minneapolis
- Flights
- 488
- Period
- July 2025 to June 2026
- Share of route
- 35%
- Carriers
- 2
Historical statistics for July 2025 to June 2026, not live status. For today’s flights, check with Southwest Airlines.
Southwest on BWI to MSP sits in the middle of the pack with a C. About seven flights in ten arrive on time by the DOT's definition, 6 points worse than the national rate of 77.6%. The late ones land about an hour behind schedule. That rests on 488 flights, with a median arrival 1 minute early.
The national on-time rate over the same period is 77.6%, so Southwest on BWI to MSP runs 6 points behind the country as a whole. Across a thousand flights that is about 61 extra late arrivals.
Key figures
On time
71.5%
Arrivals under 15 minutes late, of 480 completed flights
Avg delay
59 min
Across delayed arrivals only, not all flights
Cancelled
1.64%
National rate is 1.81%
Whole route
80.3%
Every carrier on BWI to MSP, 1,406 flights
These figures cover 488 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 BWI to MSP
Southwest flew 488 of the 1,406 flights on BWI to MSP, about 35% of it. Its 71.5% on time is 9 points worse than the route as a whole, which runs 80.3%. Ranked by on-time rate it is last of two carriers on the route, where the range runs from Delta at 85.0% to Southwest at 71.5%.
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 |
|---|---|---|---|---|---|
| Delta Air Lines | 918 | 85.0% | 92 min | 1.31% | A |
| Southwest Airlines (this page) | 488 | 71.5% | 59 min | 1.64% | C |
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–8am—
- 8am–11am108 flights83.3%
- 11am–2pm50 flights75.5%
- 2pm–5pm88 flights75.9%
- 5pm–8pm123 flights81.0%
- 8pm–5am119 flights45.2%
Scale runs 35% to 90%. Rows with fewer than 30 flights show a dash.
The 8pm–5am window is where this operation falls apart: 45.2% on time, against 83.3% 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 5pm–8pm window is the busiest, with 123 flights scheduled in it.
Across the year
Southwest on BWI to MSP through the year
June is the worst month at 49.1% on time, 38 points below November, the best at 87.5%. 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. July was the busiest month here, with 58 flights.
Across the week, Friday is the strongest day at 79.7% on time and Sunday the weakest at 56.5%. 23 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 8,097 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.
- 61%Late-arriving aircraft
- 29%Carrier
- 6%National Airspace System
- 3%Extreme weather
- 1%Security
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 8,097 reported delay minutes here, that single category outweighs weather by 18 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 8,097 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 83.3% on time here.
Cancellations sit at 1.64% against a national 1.81%, which is ordinary. Diversions add another 0.00%.
Connections and stage length
What a delay here costs
7.7% 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.
The 936 miles between these two airports put this in the middle of the US network, around two and a half to three hours of block time. That is enough cruise to absorb a ten-minute late pushback and not enough to absorb thirty. It is also long enough that the aircraft usually flies three or four legs a day rather than six, which slows how fast delay compounds.
The return leg is a different operation and performs like one: it runs 79.7% on time across 488 flights, 8 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 8 points of difference.
One caution: this is a thin sample. 488 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 BWI to MSP
Put together: treat all of this as provisional. 488 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 71.5% headline is the most reliable number on the page; the hour and month splits below it are built on a few dozen flights each. 480 completed flights over 12 months sit behind that.
Related
Where to go next
- BWI to MSP, every carrier
- Southwest on MSP to BWI, the return leg
- Delta Air Lines on BWI to MSP85.0%
- Southwest Airlines network-wide record
- Baltimore/Washington International Thurgood Marshall (BWI) delay statistics
- Minneapolis-St Paul International (MSP) 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.