Skip to content
DelayAtlas

Carrier route record

WNMSYATL

Southwest Airlines · New Orleans to Atlanta

Flights
361
Period
July 2025 to June 2026
Share of route
9%
Carriers
5
C+GRADE

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

Southwest on MSY to ATL sits in the middle of the pack with a C+. About seven flights in ten arrive on time by the DOT's definition, 7 points worse than the national rate of 77.6%. The late ones land roughly 45 minutes behind schedule. That rests on 361 flights, with a median arrival 2 minutes late.

The national on-time rate over the same period is 77.6%, so Southwest on MSY to ATL runs 7 points behind the country as a whole. Across a thousand flights that is about 68 extra late arrivals.

Key figures

On time

70.8%

Arrivals under 15 minutes late, of 359 completed flights

Avg delay

46 min

Across delayed arrivals only, not all flights

Cancelled

0.28%

National rate is 1.81%

Whole route

83.3%

Every carrier on MSY to ATL, 4,056 flights

These figures cover 361 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 MSY to ATL

Southwest flew 361 of the 4,056 flights on MSY to ATL, about 9% of it. Its 70.8% on time is 13 points worse than the route as a whole, which runs 83.3%. Ranked by on-time rate it is number four of five carriers on the route, where the range runs from American at 100.0% to Frontier at 56.8%. 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 MSY to ATL
AirlineFlightsOn timeAvg delayCancelledGrade
American Airlinesthin sample2100.0%0.00%A+
Delta Air Lines3,27887.3%65 min1.59%A
Spirit Airlinesthin sample18370.8%86 min2.73%C
Southwest Airlines (this page)thin sample36170.8%46 min0.28%C+
Frontier Airlinesthin sample23256.8%74 min1.29%D

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 30 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–11am58 flights93.1%
  • 11am–2pm65 flights81.2%
  • 2pm–5pm234 flights63.5%
  • 5pm–8pm4 flights
  • 8pm–5am

Scale runs 55% to 100%. Rows with fewer than 30 flights show a dash.

Book the morning departure. Flights leaving between 8am–11am arrive on time 93.1% of the time, against 63.5% for the afternoon window. That is 30 points of difference for no extra money, and it comes from the same aircraft having had no earlier flight to fall behind on. The 2pm–5pm window is the busiest, with 234 flights scheduled in it.

Across the year

Southwest on MSY to ATL through the year

On-time rate by calendar month94JF65M83A55MJ61J70A87S74ON63D
Darker means more delays. Figures are on-time percentages.January best, May worst

Delays peak in May, when the on-time rate falls to 54.8%. January is the strongest month at 93.9%. Moving a flexible trip across that boundary buys 39 points. January was the busiest month here, with 33 flights.

Across the week, Wednesday is the strongest day at 90.0% on time and Sunday the weakest at 53.8%. 36 points is a smaller lever than departure hour, but it is free.

On-time rate by day of the week55.8Mon89.6Tue90.0Wed65.4Thu57.4Fri86.3Sat53.8Sun
Monday: 55.8 percent on time. Tuesday: 89.6 percent on time. Wednesday: 90.0 percent on time. Thursday: 65.4 percent on time. Friday: 57.4 percent on time. Saturday: 86.3 percent on time. Sunday: 53.8 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 44% of the 4,845 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
    44%
  • Carrier
    33%
  • National Airspace System
    21%
  • Extreme weather
    1%
  • Security
    0%

44% 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 4,845 reported delay minutes here, that single category outweighs weather by 44 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 4,845 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 93.1% on time here.

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

6.1% 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 45 minutes, which a normal layover absorbs.

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 8am–11am window matters as much as it does.

The return leg is a different operation and performs like one: it runs 78.1% on time across 363 flights, 7 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 7 points of difference.

One caution: this is a thin sample. 361 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 MSY to ATL

Put together: treat all of this as provisional. 361 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 70.8% headline is the most reliable number on the page; the hour and month splits below it are built on a few dozen flights each. 359 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.