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DelayAtlas

Route reliability record

IAHMEM

Houston to Memphis

Flights
1,084
Period
July 2025 to June 2026
Distance
468 mi
Carriers
2
BGRADE

This route lands a B, 2 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 about an hour on average. That is a workable record, not a spotless one. That rests on 1,084 IAH to MEM flights, with a median arrival 4 minutes early.

Best time to fly IAH to MEM: a 5am–8am departure, ideally on a Wednesday. Flights in that window arrived on time 85.3% of the time and Wednesday flights 88.4%, against 79.5% 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

79.5%

Arrivals under 15 minutes late, of 1,072 completed flights

Avg delay

63 min

Across delayed arrivals only, not all flights

Cancelled

1.01%

National rate is 1.81%

Best carrier

SkyWest

83.4% on time across 725 flights

These figures cover 1,084 flights between July 2025 and June 2026. The median arrival is 4 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 IAH to MEM

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 IAH to MEM
AirlineFlightsOn timeAvg delayCancelledGrade
SkyWest Airlines72583.4%67 min0.83%B+
United Airlinesthin sample35971.5%57 min1.39%C

Flight by flight

Flights on IAH to MEM

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 Houston to Memphis

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.

Most reliable ways to fly from IAH to MEM
OptionAirlineSuccessOn timeCancelledBest departureMost punctual flight
1. IAHMEMHouston to MemphisSkyWest Airlines82.7%83.4%0.83%5am–8am, WedOO 5758 12:15
2. HOUMEMHouston to MemphisSouthwest Airlines72.7%73.6%1.22%11am–2pm, Tue

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.

Plan this trip by month, day and time

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 14 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–8am342 flights85.3%
  • 8am–11am1 flights
  • 11am–2pm310 flights83.7%
  • 2pm–5pm63 flights72.6%
  • 5pm–8pm14 flights
  • 8pm–5am354 flights71.6%

Scale runs 65% to 90%. Rows with fewer than 30 flights show a dash.

Book the early departure. Flights leaving between 5am–8am arrive on time 85.3% of the time, against 71.6% for the overnight window. That is 14 points of difference for no extra money, and it comes from the same aircraft having had no earlier flight to fall behind on. The 8pm–5am window is the busiest, with 354 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.

On-time rate by calendar month82J83F74M73A76M80J78J78A92S83O79N79D
Darker means more delays. Figures are on-time percentages.September best, April worst

September is the best month on the calendar at 92.1% on time. Shoulder season thins the schedule and takes the summer weather with it, and the operation gets its margin back. April was the busiest month here, with 118 flights.

Across the week, Wednesday is the strongest day at 88.4% on time and Friday the weakest at 67.3%. 21 points is a smaller lever than departure hour, but it is free.

On-time rate by day of the week76.1Mon80.0Tue88.4Wed87.8Thu67.3Fri77.8Sat78.4Sun
Monday: 76.1 percent on time. Tuesday: 80.0 percent on time. Wednesday: 88.4 percent on time. Thursday: 87.8 percent on time. Friday: 67.3 percent on time. Saturday: 77.8 percent on time. Sunday: 78.4 percent on time

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 14,000 reported delay minutes.

  • Carrier
    42%
  • Late-arriving aircraft
    40%
  • National Airspace System
    10%
  • Extreme weather
    8%

40% 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 14,000 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 13,805 reported delay minutes.

The largest share of delay minutes, 42%, falls under carrier control: crew scheduling, maintenance, fuelling, baggage. Unlike weather, that is a management outcome, and it is the category where the gap between two carriers on the same schedule is genuinely earned. It accounts for 5,736 of the 14,000 delay minutes reported here.

Cancellations sit at 1.01% against a national 1.81%, which is ordinary. Diversions add another 0.09%.

Connections and stage length

What a delay here actually costs

6.5% 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 about 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 5am–8am window matters as much as it does.

The return leg runs 80.1% on time across 1,082 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. 1,084 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 MEM after this flight

What to do with this

Booking this route

Put together: treat all of this as provisional. 1,084 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 79.5% headline is the most reliable number on the page; the hour and month splits below it are built on a few dozen flights each. 1,072 completed flights over 12 months sit behind that.

Common questions

IAH to MEM questions

How often is IAH to MEM 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 20.5% of the 1,084 flights in this analysis, against 22.4% nationally. Delayed flights are late by about an hour on average.

How reliable is IAH to MEM compared with the rest of the country?

79.5% of flights arrive on time here against a national 77.6%, a difference of 2 points in its favour. That is worth a B on this site's grading scale.

What time of day has the fewest delays on IAH to MEM?

The 5am–8am departure window is the strongest at 85.3% on time. The 8pm–5am window is the weakest at 71.6%, 14 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 April delays on IAH to MEM?

April is the weakest month at 72.6% on time, compared with 92.1% in September. 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

Direction matters. IAH to MEM and MEM to IAH are scored separately because they are separate operations, with different departure banks and different aircraft. Compare the return leg.

Embed IAH to MEM’s on-time badge on your site

Paste this into a web page. The badge shows the current on-time rate, cancellation rate and grade, and updates every month. Preview it, or build a badge for another route or airport.

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.