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DelayAtlas

Carrier route record

WNATLMSY

Southwest Airlines · Atlanta to New Orleans

Flights
363
Period
July 2025 to June 2026
Share of route
9%
Carriers
5
B+GRADE

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

Southwest on ATL to MSY lands a B+, level with the national rate of 77.6%. Roughly one flight in five arrives 15 minutes late or worse, and those flights are late by about 45 minutes on average. That is a workable record, not a spotless one. That rests on 363 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 ATL 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

78.1%

Arrivals under 15 minutes late, of 361 completed flights

Avg delay

46 min

Across delayed arrivals only, not all flights

Cancelled

0.28%

National rate is 1.81%

Whole route

81.4%

Every carrier on ATL to MSY, 4,052 flights

These figures cover 363 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 ATL to MSY

Southwest flew 363 of the 4,052 flights on ATL to MSY, about 9% of it. Its 78.1% on time is 3 points worse than the route as a whole, which runs 81.4%. Ranked by on-time rate it is number three of five carriers on the route, where the range runs from American at 100.0% to Frontier at 63.6%. Three 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 ATL to MSY
AirlineFlightsOn timeAvg delayCancelledGrade
American Airlinesthin sample3100.0%0.00%A+
Delta Air Lines3,27583.2%58 min1.53%B
Southwest Airlines (this page)thin sample36378.1%46 min0.28%B+
Spirit Airlinesthin sample18076.6%76 min2.78%B
Frontier Airlinesthin sample23163.6%74 min1.30%D

Departure window

When Southwest runs best on this route

Departure time is the single lever a traveller controls, and it moves the odds more than most people expect. Each bar below is the on-time rate for flights scheduled to leave inside that window, across 363 flights.

There are not enough flights in each departure window to split Southwest's ATL to MSY record by time of day without the percentages moving on noise. The headline rate of 78.1% is the reliable figure here.

Across the year

Southwest on ATL to MSY through the year

On-time rate by calendar month94JF81M80A55MJ58J87A97S81O83N67D
Darker means more delays. Figures are on-time percentages.September best, May worst

September is the best month on the calendar at 96.7% on time. Shoulder season thins the schedule and takes the summer weather with it, and the operation gets its margin back. December was the busiest month here, with 33 flights.

Across the week, Wednesday is the strongest day at 90.4% on time and Sunday the weakest at 61.5%. 29 points is a smaller lever than departure hour, but it is free.

On-time rate by day of the week76.9Mon77.6Tue90.4Wed82.7Thu75.5Fri82.4Sat61.5Sun
Monday: 76.9 percent on time. Tuesday: 77.6 percent on time. Wednesday: 90.4 percent on time. Thursday: 82.7 percent on time. Friday: 75.5 percent on time. Saturday: 82.4 percent on time. Sunday: 61.5 percent on time

Delay causes

Why Southwest runs late on this route

One category carries most of the weight here. Late-arriving aircraft accounts for 58% of the 3,605 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
    58%
  • Carrier
    20%
  • National Airspace System
    19%
  • Extreme weather
    3%
  • Security
    1%

58% 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 3,605 reported delay minutes here, that single category outweighs weather by 19 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 3,605 reported delay minutes.

Cancellations are rare at 0.28%, 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

Badly late arrivals are rare here: only 4.2% land an hour or more behind schedule, against 8.1% nationally. Connections built on this flight are about as safe as US domestic connections get, though a cancelled flight still ignores every layover you give it.

At 425 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 2pm–5pm window matters as much as it does.

The return leg is a different operation and performs like one: it runs 70.8% on time across 361 flights, 7 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 7 points of difference.

One caution: this is a thin sample. 363 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 ATL to MSY

Put together: treat all of this as provisional. 363 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 78.1% headline is the most reliable number on the page; the hour and month splits below it are built on a few dozen flights each. 361 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.