Route reliability record
MSY→IAH
New Orleans to Houston
- Flights
- 2,961
- Period
- July 2025 to June 2026
- Distance
- 305 mi
- Carriers
- 4
This route lands a B+, 5 points better than the national rate of 77.6%. About one flight in six arrive 15 minutes late or worse, and those flights are late by a little over an hour on average. That is a workable record, not a spotless one. That rests on 2,961 flights, with a median arrival 10 minutes early.
Set against the rest of the country, this route's record is 5 points better than the US average of 77.6%. That gap is worth roughly 46 fewer late arrivals for every thousand flights.
Key figures
On time
82.2%
Arrivals under 15 minutes late, of 2,943 completed flights
Avg delay
76 min
Across delayed arrivals only, not all flights
Cancelled
0.51%
National rate is 1.81%
Best carrier
United
82.4% on time across 2,784 flights
These figures cover 2,961 flights between July 2025 and June 2026. The median arrival is 10 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
Which airline is most reliable on MSY to IAH
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 |
|---|---|---|---|---|---|
| United Airlines | 2,784 | 82.4% | 74 min | 0.47% | B+ |
| Frontier Airlinesthin sample | 27 | 80.8% | 305 min | 3.70% | B− |
| Spirit Airlinesthin sample | 146 | 77.9% | 65 min | 0.68% | B+ |
| SkyWest Airlinesthin sample | 4 | 75.0% | 122 min | 0.00% | B+ |
Departure window
The best time of day to leave
Departure time matters more here than the choice of carrier. The gap between the best and worst window is 17 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–8am709 flights86.9%
- 8am–11am348 flights90.5%
- 11am–2pm346 flights83.1%
- 2pm–5pm749 flights80.7%
- 5pm–8pm678 flights73.8%
- 8pm–5am131 flights84.0%
Scale runs 65% to 95%. Rows with fewer than 30 flights show a dash.
Book the morning departure. Flights leaving between 8am–11am arrive on time 90.5% of the time, against 73.8% for the evening window. That is 17 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 749 flights scheduled in it.
Across the year
When delays peak on this route
This route's year swings by 20 points from best month to worst, which is wide. An annual average tells you very little about the week you are actually flying, so read the strip rather than the headline if your dates are fixed.
Delays peak in May, when the on-time rate falls to 71.8%. January is the strongest month at 91.9%. Moving a flexible trip across that boundary buys 20 points. October was the busiest month here, with 286 flights.
Across the week, Tuesday is the strongest day at 86.0% on time and Sunday the weakest at 77.7%. 8 points is a smaller lever than departure hour, but it is free.
Delay causes
Why this route gets delayed
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 40,000 reported delay minutes.
- 36%Late-arriving aircraft
- 35%National Airspace System
- 22%Carrier
- 7%Extreme weather
36% 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 40,000 reported delay minutes here, that single category outweighs weather by 5 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 39,731 reported delay minutes.
35% of delay minutes are charged to the National Airspace System: air traffic volume, runway configuration, ground stops. No carrier can price its way out of that, which is why airport choice moves the number here more than carrier choice does. That is 14,000 minutes out of 40,000, against a national NAS share of 21%.
Cancellations are rare at 0.51%, 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 actually costs
6.2% 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 are the a little over an hour kind, which a normal layover absorbs.
At 305 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 runs 82.9% on time across 2,962 flights, within half a point of this direction. The two legs are scored separately because they usually differ; on this city pair they happen not to.
The sample behind these figures is 2,961 flights, enough that the headline rate is stable to within roughly a point. The hour-block and month splits divide that further, so read the thinner bars with more caution than the headline.
What to do with this
Booking this route
Put together: the calendar is the biggest lever here, not the carrier or the hour. January runs 91.9% on time and May 71.8%, a swing of 20 points. If the dates move at all, move them out of May before you think about anything else. 2,943 completed flights over 12 months sit behind that.
Common questions
MSY to IAH questions
How often is MSY to IAH delayed?
About one flight in six arrive at least 15 minutes late, which is the Department of Transportation's definition of a delayed arrival. That works out to 17.8% of the 2,961 flights in this analysis, against 22.4% nationally. Delayed flights are late by a little over an hour on average.
How reliable is MSY to IAH compared with the rest of the country?
82.2% of flights arrive on time here against a national 77.6%, a difference of 5 points in its favour. That is worth a B+ on this site's grading scale.
What time of day has the fewest delays on MSY to IAH?
The 8am–11am departure window is the strongest at 90.5% on time. The 5pm–8pm window is the weakest at 73.8%, 17 points behind. Later departures inherit delays from earlier flights the same aircraft has already flown, which is why the curve slopes the way it does.
How bad are May delays on MSY to IAH?
May is the weakest month at 71.8% on time, compared with 91.9% in January. Across the year that is 20 points between the best and worst months. Moving flexible dates out of that month is one of the few things that reliably helps.
Related
Where to go next
- IAH to MSY — the return legseparate record
- Louis Armstrong New Orleans International (MSY) delay statistics
- George Bush Intercontinental (IAH) delay statistics
- United Airlines on-time record82.4%
- Frontier Airlines on-time record80.8%
- Spirit Airlines on-time record77.9%
- Why the first flight of the morning is statistically safest
- The best time of day to fly, according to 7.04 million flight records
Direction matters. MSY to IAH and IAH to MSY are scored separately because they are separate operations, with different departure banks and different aircraft. Compare the return leg.
Source: US DOT Bureau of Transportation Statistics, on-time performance data, July 2025 to June 2026. Updated monthly. How this data is collected.