Airport month record

MSYSEP

Louis Armstrong New Orleans International in September 2025

Departures: 3,619
Month: September 2025
National, same month: 83.4%
Carriers: 11

Historical statistics for September 2025, not live status or a forecast for this year’s September. For today’s conditions at MSY, see live FAA status.

MSY in September earns an A+. More than four flights in five arrive inside the 15-minute window the DOT uses to define an on-time arrival, which puts it 3 points better than the national rate of 83.4%. When something does go wrong the average delay runs a little over an hour. That rests on 3,619 flights, of which United Airlines flew 529 at 91.1% on time.

United Airlines is the most reliable of the five carriers covered here at 91.1% on time across 529 flights.

On time

85.9%

Arrivals under 15 minutes late, of 3,597 completed departures

Avg delay

70 min

Across delayed arrivals only, not all flights

Cancelled

0.36%

Nationally in September: 0.51%

Whole year

78.5%

MSY across all twelve months

These figures cover 3,619 departures from Louis Armstrong New Orleans International in September 2025. On time means an arrival less than 15 minutes after the scheduled gate time, the DOT's threshold, and the national comparison uses every US departure in the same month rather than the whole year.

Against the year

September next to MSY's other months

Against MSY's own year, September ran 7 points better than the twelve-month rate of 78.5%, which makes it the best of the twelve months in the data. Cancellations were unusually low for MSY in September, at 0.36% against 1.47% across the year. Either side of it, August ran 80.2% on time and October 78.9%, so a trip moved by a few weeks would have landed in a worse stretch.

MSY month by month
Month	Flights	On time	Avg delay	Cancelled	Grade
July 2025	4,039	71.9%	82 min	1.81%	C
August 2025	3,739	80.2%	80 min	1.10%	B
September 2025 (this page)	3,619	85.9%	70 min	0.36%	A+
October 2025	4,699	78.9%	56 min	0.53%	B+
November 2025	4,314	81.1%	80 min	1.27%	B
December 2025	4,152	78.0%	74 min	1.28%	B
January 2026	3,901	84.9%	72 min	4.13%	B−
February 2026	4,111	82.8%	68 min	1.82%	B
March 2026	4,485	75.3%	75 min	2.79%	B
April 2026	4,428	80.1%	63 min	0.65%	B+
May 2026	4,194	73.5%	69 min	0.83%	C+
June 2026	3,709	70.0%	78 min	1.11%	C

Departure window

The best time of day to leave MSY in September

Departure time matters more here than the choice of carrier. The gap between the best and worst window is 15 points, against 11 points between the best and worst carrier. Each bar is the on-time rate for flights scheduled inside that window.

5am–8am758 flights93.2%
8am–11am669 flights92.8%
11am–2pm566 flights86.8%
2pm–5pm724 flights80.8%
5pm–8pm703 flights77.9%
8pm–5am199 flights78.6%

Scale runs 70% to 100%. Rows with fewer than 30 flights show a dash.

Book the early departure. Flights leaving between 5am–8am arrive on time 93.2% of the time, against 77.9% for the evening window. That is 15 points of difference for no extra money, and it comes from the same aircraft having had no earlier flight to fall behind on. The 5am–8am window is the busiest, with 758 flights scheduled in it.

Across the week, Tuesday is the strongest day at 90.5% on time and Sunday the weakest at 81.0%. 10 points is a smaller lever than departure hour, but it is free.

Carrier by carrier

Which airlines ran best at MSY in September

The choice of carrier is not cosmetic here. United Airlines arrives on time 91.1% of the time; American Airlines manages 80.6%. Sample sizes sit next to every figure, because a two-point gap across 407 flights means less than a ten-point one.

Carriers at MSY in September 2025
Airline	Flights	On time	Avg delay	Cancelled	Grade
Southwest Airlines	1,292	86.5%	47 min	0.08%	A+
Delta Air Lines	567	90.3%	97 min	0.18%	A+
United Airlines	529	91.1%	53 min	0.38%	A+
American Airlines	407	80.6%	108 min	0.98%	B+
Spirit Airlines	382	82.9%	66 min	0.52%	B+
Envoy Airthin sample	116	82.3%	46 min	1.72%	B
Republic Airwaysthin sample	71	87.1%	36 min	0.00%	A+
PSA Airlinesthin sample	67	80.6%	141 min	0.00%	B+
SkyWest Airlinesthin sample	60	91.5%	122 min	0.00%	A+
JetBlue Airwaysthin sample	52	57.7%	73 min	0.00%	D+
Alaska Airlinesthin sample	47	78.3%	45 min	2.13%	B

United leads American by 11 points. Real, but small enough that a better departure time on the weaker carrier can outweigh it.

Route by route

Busiest routes out of MSY in September

Routes from MSY in September 2025
Route	Flights	On time	Avg delay	Cancelled	Grade
MSY to ATL · Atlantathin sample	304	94.1%	66 min	0.00%	A+
MSY to IAH · Houstonthin sample	280	91.0%	29 min	0.71%	A+
MSY to DFW · Dallas-Fort Worththin sample	234	78.1%	114 min	2.14%	B
MSY to DAL · Dallasthin sample	179	88.8%	59 min	0.56%	A+
MSY to AUS · Austinthin sample	177	89.2%	58 min	0.00%	A+
MSY to HOU · Houstonthin sample	176	85.8%	49 min	0.00%	A+
MSY to DEN · Denverthin sample	155	81.9%	59 min	0.00%	B+
MSY to DCA · Washingtonthin sample	142	72.5%	80 min	0.00%	C+
MSY to ORD · Chicagothin sample	142	93.6%	100 min	0.70%	A+
MSY to MCO · Orlandothin sample	142	89.4%	74 min	0.00%	A+
MSY to LAX · Los Angelesthin sample	121	86.0%	86 min	0.00%	A+
MSY to BNA · Nashvillethin sample	120	95.0%	38 min	0.00%	A+
MSY to LGA · New Yorkthin sample	116	86.2%	60 min	0.00%	A+
MSY to MIA · Miamithin sample	110	78.0%	51 min	0.00%	B+
MSY to CLT · Charlottethin sample	107	89.7%	144 min	0.00%	A+
MSY to FLL · Fort Lauderdalethin sample	97	86.3%	34 min	1.03%	A
MSY to BWI · Baltimorethin sample	96	86.5%	44 min	0.00%	A+
MSY to PHL · Philadelphiathin sample	88	85.2%	58 min	0.00%	A+
MSY to JFK · New Yorkthin sample	82	90.2%	93 min	0.00%	A+
MSY to MDW · Chicagothin sample	81	86.2%	27 min	0.00%	A+
MSY to EWR · Newarkthin sample	74	86.3%	89 min	0.00%	A+
MSY to LAS · Las Vegasthin sample	73	79.5%	30 min	0.00%	B+
MSY to TPA · Tampathin sample	63	88.7%	31 min	1.59%	A
MSY to BOS · Bostonthin sample	60	30.5%	76 min	1.67%	F
MSY to DTW · Detroitthin sample	51	82.4%	138 min	0.00%	B+

Delay causes

What held MSY up in September

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 35,000 reported delay minutes.

Late-arriving aircraft
38%
Carrier
31%
National Airspace System
28%
Extreme weather
3%
Security
0%

38% 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 35,000 reported delay minutes here, that single category outweighs weather by 12 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 35,291 reported delay minutes.

Cancellations are rare at 0.36%, below the national 0.51% 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.

Badly late arrivals are rare here: only 4.8% land an hour or more behind schedule, against 5.4% 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.

What to do with this

Flying from MSY in September

For a September trip through MSY: this is one of the better months to be flying from here, 85.9% on time with 0.36% cancelled. That is a base rate for the month as a whole; a single storm can still spoil a particular day.

Louis Armstrong New Orleans International (MSY), the whole year
MSY in July71.9%
MSY in August80.2%
MSY in October78.9%
MSY in November81.1%
MSY in December78.0%
MSY in January84.9%
MSY in February82.8%
MSY in March75.3%
MSY in April80.1%
MSY in May73.5%
MSY in June70.0%

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