Route reliability record

IAH→CLT

Houston to Charlotte

Flights: 2,348
Period: July 2025 to June 2026
Distance: 912 mi
Carriers: 4

This route lands a B, 2 points better than the national rate of 77.6%. About one flight in five arrive 15 minutes late or worse, and those flights are late by close to two hours on average. That is a workable record, not a spotless one. That rests on 2,348 flights, of which American Airlines flew 1,622 at 82.4% on time.

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.

On time

79.5%

Arrivals under 15 minutes late, of 2,298 completed flights

Avg delay

104 min

Across delayed arrivals only, not all flights

Cancelled

2.04%

National rate is 1.81%

Best carrier

American

82.4% on time across 1,622 flights

These figures cover 2,348 flights between July 2025 and June 2026. Beyond the headline rate, 9.1% of arrivals land a full hour or more behind schedule. That is the number that wrecks a connection, and it is not visible in an on-time percentage alone.

Carrier by carrier

Which airline is most reliable on IAH to CLT

The choice of carrier is not cosmetic here. American Airlines arrives on time 82.4% of the time; United Airlines manages 74.7%. Sample sizes sit next to every figure, because a two-point gap across 394 flights means less than a ten-point one.

On-time performance by carrier on IAH to CLT
Airline	Flights	On time	Avg delay	Cancelled	Grade
American Airlines	1,622	82.4%	135 min	1.97%	B
SkyWest Airlinesthin sample	115	76.1%	53 min	1.74%	B
United Airlines	394	74.7%	60 min	1.52%	C
Frontier Airlinesthin sample	217	67.5%	58 min	3.69%	C−

American leads United by 8 points. Real, but small enough that a better departure time on the weaker carrier can outweigh it.

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 20 points, against 8 points between the best and worst carrier. Each bar is the on-time rate for flights scheduled inside that window.

5am–8am499 flights89.5%
8am–11am404 flights85.1%
11am–2pm398 flights78.5%
2pm–5pm330 flights79.0%
5pm–8pm717 flights70.0%
8pm–5am—

Scale runs 60% to 95%. Rows with fewer than 30 flights show a dash.

Book the early departure. Flights leaving between 5am–8am arrive on time 89.5% of the time, against 70.0% for the evening window. That is 20 points of difference for no extra money, and it comes from the same aircraft having had no earlier flight to fall behind on. The 5pm–8pm window is the busiest, with 717 flights scheduled in it.

Across the year

When delays peak on this route

This route's year swings by 27 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.

Darker means more delays. Figures are on-time percentages.January best, July worst

July is the worst month at 64.2% on time, 27 points below January, the best at 91.1%. Summer afternoon convection and peak-season schedules land on the same weeks every year, so this is a pattern you can book around rather than a run of bad luck. March was the busiest month here, with 227 flights.

Across the week, Tuesday is the strongest day at 82.1% on time and Friday the weakest at 77.7%. 4 points is a smaller lever than departure hour, but it is free.

Delay causes

Why this route gets delayed

One category carries most of the weight here. Late-arriving aircraft accounts for 47% of the 49,000 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
47%
Carrier
36%
National Airspace System
10%
Extreme weather
7%
Security
0%

47% 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 49,000 reported delay minutes here, that single category outweighs weather by 7 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 48,950 reported delay minutes.

The largest share of delay minutes, 36%, 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 18,000 of the 49,000 delay minutes reported here.

Cancellations sit at 2.04% against a national 1.81%, which is ordinary. Diversions add another 0.09%.

Connections and stage length

What a delay here actually costs

For anyone connecting, the number to weigh is not the on-time rate but the tail behind it. 9.1% of arrivals land a full hour or more behind schedule, against 8.1% nationally. A 45-minute layover does not survive that, and no amount of walking quickly changes it. Ninety minutes is the honest minimum here, and two hours if the onward flight is on a separate ticket.

The 912 miles between these two airports put this in the middle of the US network, around two and a half to three hours of block time. That is enough cruise to absorb a ten-minute late pushback and not enough to absorb thirty. It is also long enough that the aircraft usually flies three or four legs a day rather than six, which slows how fast delay compounds.

The return leg runs 77.6% on time across 2,348 flights, within 2 points 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 2,348 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 91.1% on time and July 64.2%, a swing of 27 points. If the dates move at all, move them out of July before you think about anything else. 2,298 completed flights over 12 months sit behind that.

Common questions

IAH to CLT questions

How often is IAH to CLT delayed?

About one flight in five arrive 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 2,348 flights in this analysis, against 22.4% nationally. Delayed flights are late by close to two hours on average.

Which airline is most reliable on IAH to CLT?

American Airlines leads at 82.4% on time across 1,622 flights. United Airlines is at the other end on 74.7%, a gap of 8 points. Sample size matters as much as the percentage: a rate built from a few hundred flights moves around far more than one built from ten thousand.

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

The 5am–8am departure window is the strongest at 89.5% on time. The 5pm–8pm window is the weakest at 70.0%, 20 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 July delays on IAH to CLT?

July is the weakest month at 64.2% on time, compared with 91.1% in January. Across the year that is 27 points between the best and worst months. Moving flexible dates out of that month is one of the few things that reliably helps.

Where to go next

Direction matters. IAH to CLT and CLT to IAH 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.

Key figures