Skip to content
DelayAtlas

Carrier route record

WNBWIMSY

Southwest Airlines · Baltimore to New Orleans

Flights
1,031
Period
July 2025 to June 2026
Share of route
87%
Carriers
3
BGRADE

Historical statistics for July 2025 to June 2026, not live status. For today’s flights, check with Southwest Airlines.

Southwest on BWI to MSY lands a B, about a point 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 about an hour on average. That is a workable record, not a spotless one. That rests on 1,031 flights, with a median arrival 4 minutes early.

The US average over the same twelve months is 77.6%, so there is little to separate Southwest on BWI to MSY from the country as a whole. The variation that matters here is internal: which carrier, and what time of day.

Key figures

On time

76.7%

Arrivals under 15 minutes late, of 1,018 completed flights

Avg delay

57 min

Across delayed arrivals only, not all flights

Cancelled

1.16%

National rate is 1.81%

Whole route

77.4%

Every carrier on BWI to MSY, 1,180 flights

These figures cover 1,031 flights between July 2025 and June 2026. The median arrival is 4 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 BWI to MSY

Southwest flew 1,031 of the 1,180 flights on BWI to MSY, most of the route. Its 76.7% on time is about level with the route as a whole at 77.4%. Ranked by on-time rate it is number two of three carriers on the route, where the range runs from Spirit at 84.5% to Frontier at 66.7%. Two 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 BWI to MSY
AirlineFlightsOn timeAvg delayCancelledGrade
Spirit Airlinesthin sample13184.5%95 min1.53%B
Southwest Airlines (this page)1,03176.7%57 min1.16%B
Frontier Airlinesthin sample1866.7%68 min0.00%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 25 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–8am15 flights
  • 8am–11am306 flights90.1%
  • 11am–2pm61 flights86.9%
  • 2pm–5pm279 flights71.1%
  • 5pm–8pm126 flights73.2%
  • 8pm–5am244 flights64.9%

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

The 8pm–5am window is where this operation falls apart: 64.9% on time, against 90.1% 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 306 flights scheduled in it.

Across the year

Southwest on BWI to MSY through the year

On-time rate by calendar month85J87F84M76A72M56J62J85A80S80O86N74D
Darker means more delays. Figures are on-time percentages.February best, June worst

June is the worst month at 55.8% on time, 31 points below February, the best at 86.7%. 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. March was the busiest month here, with 95 flights.

Across the week, Saturday is the strongest day at 86.7% on time and Friday the weakest at 66.7%. 20 points is a smaller lever than departure hour, but it is free.

On-time rate by day of the week80.0Mon81.7Tue79.6Wed70.7Thu66.7Fri86.7Sat74.6Sun
Monday: 80.0 percent on time. Tuesday: 81.7 percent on time. Wednesday: 79.6 percent on time. Thursday: 70.7 percent on time. Friday: 66.7 percent on time. Saturday: 86.7 percent on time. Sunday: 74.6 percent on time

Delay causes

Why Southwest runs late on this route

Carriers report a reason for every delay minute they cause, in five DOT categories. The split below is by minutes, not by number of flights, so a handful of very long weather delays weighs as much as many short ones. It covers 13,000 reported delay minutes.

  • Late-arriving aircraft
    41%
  • Carrier
    36%
  • National Airspace System
    15%
  • Extreme weather
    7%
  • Security
    1%

41% 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 13,000 reported delay minutes here, that single category outweighs weather by 6 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 13,475 reported delay minutes.

The largest share of delay minutes, 36%, falls under carrier control: crew scheduling, maintenance, fuelling, baggage. Unlike weather, that is a management outcome, and it is the category where the gap between two carriers on the same schedule is genuinely earned. It accounts for 4,804 of the 13,000 delay minutes reported here.

Cancellations sit at 1.16% against a national 1.81%, which is ordinary. Diversions add another 0.10%.

Connections and stage length

What a delay here costs

6.7% 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 998 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 81.1% on time across 1,030 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. 1,031 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 MSY

Put together: treat all of this as provisional. 1,031 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 76.7% headline is the most reliable number on the page; the hour and month splits below it are built on a few dozen flights each. 1,018 completed flights over 12 months sit behind that.

Related

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.