Route reliability record
MEM→IAH
Memphis to Houston
- Flights
- 1,082
- Period
- July 2025 to June 2026
- Distance
- 468 mi
- Carriers
- 2
This route lands a B, 3 points better than the national rate of 77.6%. About one flight in five arrives 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 1,082 MEM to IAH flights, with a median arrival 7 minutes early.
Best time to fly MEM to IAH: a 8am–11am departure, ideally on a Tuesday. Flights in that window arrived on time 89.7% of the time and Tuesday flights 85.6%, against 80.1% for the route overall.
The US average over the same twelve months is 77.6%, so there is little to separate this route from the country as a whole. The variation that matters here is internal: which carrier, and what time of day.
Key figures
On time
80.1%
Arrivals under 15 minutes late, of 1,070 completed flights
Avg delay
71 min
Across delayed arrivals only, not all flights
Cancelled
1.02%
National rate is 1.81%
Best carrier
SkyWest
77.9% on time across 722 flights
These figures cover 1,082 flights between July 2025 and June 2026. The median arrival is 7 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 MEM 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 Airlinesthin sample | 360 | 84.5% | 48 min | 1.67% | B |
| SkyWest Airlines | 722 | 77.9% | 79 min | 0.69% | B+ |
Flight by flight
Flights on MEM to IAH
The flight numbers below flew this route at least 250 times in the period, busiest first. Each has its own record, with its schedule and delay causes.
Best ways to make this trip
The most reliable ways to fly Memphis to Houston
Every airline on this route and on the routes between nearby airports, ranked by how often a scheduled flight actually operated and arrived on time. 1 of the top 2 use a different airport at one end.
| Option | Airline | Success | On time | Cancelled | Best departure | Most punctual flight |
|---|---|---|---|---|---|---|
| 1. MEM → HOUMemphis to Houston | Southwest Airlines | 78.0% | 78.6% | 0.73% | 5am–8am, Tue | — |
| 2. MEM → IAHMemphis to Houston | SkyWest Airlines | 77.4% | 77.9% | 0.69% | 8am–11am, Tue | OO 5798 15:26 |
Success is the share of scheduled flights that operated and arrived less than 15 minutes late, so a cancelled flight counts against it. “(route)” means the best time comes from every carrier on the route rather than this airline alone.
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 18 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–8am356 flights84.3%
- 8am–11am68 flights89.7%
- 11am–2pm341 flights81.0%
- 2pm–5pm311 flights72.2%
- 5pm–8pm6 flights—
- 8pm–5am—
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 89.7% of the time, against 72.2% for the afternoon window. That is 18 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 356 flights scheduled in it.
Across the year
When delays peak on this route
This route's year swings by 25 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.
December is the weak month at 69.2% on time, against 94.0% in September. Winter delays cluster: a single storm system can account for most of a month's shortfall, so an average December hides both very good weeks and genuinely unflyable days. April was the busiest month here, with 119 flights.
Across the week, Tuesday is the strongest day at 85.6% on time and Friday the weakest at 76.2%. 9 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 15,000 reported delay minutes.
- 34%Late-arriving aircraft
- 30%National Airspace System
- 28%Carrier
- 8%Extreme weather
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 89.7% on time here. The split is drawn from 15,131 reported delay minutes.
No single cause dominates. late-arriving aircraft at 34%, national airspace system at 30% and carrier at 28% split the 15,000 reported delay minutes between them. An even spread like this usually means the operation is running close to its designed capacity with no one obvious weak point, and it is the hardest pattern for a traveller to route around.
Cancellations sit at 1.02% against a national 1.81%, which is ordinary. Diversions add another 0.09%.
Connections and stage length
What a delay here actually costs
6.4% 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 a little over an hour, which a normal layover absorbs.
At 468 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 79.5% on time across 1,084 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.
One caution: this is a thin sample. 1,082 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.
Work out the risk of missing a connection in IAH after this flight
What to do with this
Booking this route
Put together: treat all of this as provisional. 1,082 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 80.1% headline is the most reliable number on the page; the hour and month splits below it are built on a few dozen flights each. 1,070 completed flights over 12 months sit behind that.
Common questions
MEM to IAH questions
How often is MEM to IAH delayed?
About one flight in five arrives at least 15 minutes late, which is the Department of Transportation's definition of a delayed arrival. That works out to 19.9% of the 1,082 flights in this analysis, against 22.4% nationally. Delayed flights are late by a little over an hour on average.
How reliable is MEM to IAH compared with the rest of the country?
80.1% of flights arrive on time here against a national 77.6%, a difference of 3 points in its favour. That is worth a B on this site's grading scale.
What time of day has the fewest delays on MEM to IAH?
The 8am–11am departure window is the strongest at 89.7% on time. The 2pm–5pm window is the weakest at 72.2%, 18 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 December delays on MEM to IAH?
December is the weakest month at 69.2% on time, compared with 94.0% in September. Across the year that is 25 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 MEM — the return legseparate record
- George Bush Intercontinental (IAH) delay statistics
- United Airlines on MEM to IAH84.5%
- SkyWest Airlines on MEM to IAH77.9%
- MEM to ATL, a related route87.4%
- ORD to IAH, a related route75.0%
- MEM to ORD, a related route76.0%
- United Airlines on-time record84.5%
- SkyWest 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. MEM to IAH and IAH to MEM are scored separately because they are separate operations, with different departure banks and different aircraft. Compare the return leg.
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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.