Route reliability record
IAH→CLE
Houston to Cleveland
- Flights
- 815
- Period
- September 2025 to August 2026
- Distance
- 1,091 mi
- Carriers
- 1
This route 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 8 points better than the national rate of 77.3%. When something does go wrong the average delay runs about an hour. That rests on 815 IAH to CLE flights, with a median arrival 8 minutes early.
Best time to fly IAH to CLE: a 5am–8am departure, ideally on a Wednesday. Flights in that window arrived on time 92.5% of the time and Wednesday flights 92.3%, against 85.1% for the route overall.
Set against the rest of the country, this route's record is 8 points better than the US average of 77.3%. That gap is worth roughly 78 fewer late arrivals for every thousand flights.
Key figures
On time
85.1%
Arrivals under 15 minutes late, of 813 completed flights
Avg delay
55 min
Across delayed arrivals only, not all flights
Cancelled
0.12%
National rate is 1.89%
Best carrier
United
85.1% on time across 815 flights
These figures cover 815 flights between September 2025 and August 2026. The median arrival is 8 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.
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Carrier by carrier
Which airline is most reliable on IAH to CLE
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 | 815 | 85.1% | 55 min | 0.12% | A+ |
Flight by flight
Flights on IAH to CLE
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.
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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 19 points, against half a point between the best and worst carrier.
- 5am–8am361 flights92.5%
- 8am–11am—
- 11am–2pm20 flights—
- 2pm–5pm104 flights73.1%
- 5pm–8pm330 flights80.5%
- 8pm–5am—
Scale runs 65% to 100%. Rows with fewer than 30 flights show a dash.
Book the early departure. Flights leaving between 5am–8am arrive on time 92.5% of the time, against 73.1% for the afternoon window. That is 19 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 361 flights scheduled in it.
Explore
Filter IAH to CLE by airline, time, month and day
Pick a breakdown and a carrier. The dashed mark on each row is the same slice for every US flight.
On IAH to CLE, the best departure window is 5am–8am at 92.5% on time and the worst is 2pm–5pm at 73.1%, a wide gap of 19.4 points. All US flights leaving 5am–8am ran 89.3%.
- 5–8am92.5%
- 8–11am—
- 11am–2pm—
- 2–5pm73.1%
- 5–8pm80.5%
- 8pm–5am—
best all US flightsScale 60% to 95%. Cells under 30 flights show a dash.
Across the year
When delays peak on this route
This route's year swings by 23 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.
June is the worst month at 72.1% on time, 23 points below January, the best at 95.1%. 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. July was the busiest month here, with 89 flights.
Across the week, Wednesday is the strongest day at 92.3% on time and Sunday the weakest at 77.6%, a spread of 15 points.
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 6,702 reported delay minutes.
- 41%Late-arriving aircraft
- 39%Carrier
- 12%National Airspace System
- 8%Extreme weather
41% of delay minutes trace back to a late-arriving aircraft, meaning the plane was already behind before it got here. Across 6,702 reported delay minutes here, that single category outweighs weather by 5 to one. The split is drawn from 6,702 reported delay minutes.
The largest share of delay minutes, 39%, falls under carrier control: crew scheduling, maintenance, fuelling, baggage. It accounts for 2,612 of the 6,702 delay minutes reported here.
Cancellations are rare at 0.12%, below the national 1.89% 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
Badly late arrivals are rare here: only 3.9% land an hour or more behind schedule, against 8.3% 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.
The 1,091 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.
The return leg is a different operation and performs like one: it runs 90.8% on time across 814 flights, 6 points above this direction. Departure banks, aircraft rotations and the congestion at each end all differ, so scoring the two directions together would average away a real 6 points of difference.
One caution: this is a thin sample. 815 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 CLE after this flight
What to do with this
Booking this route
Put together: treat all of this as provisional. 815 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 85.1% headline is the most reliable number on the page; the hour and month splits below it are built on a few dozen flights each. 813 completed flights over 12 months sit behind that.
Common questions
IAH to CLE questions
How often is IAH to CLE delayed?
About one flight in seven arrives at least 15 minutes late, which is the Department of Transportation's definition of a delayed arrival. That works out to 14.9% of the 815 flights in this analysis, against 22.7% nationally. Delayed flights are late by about an hour on average.
How reliable is IAH to CLE compared with the rest of the country?
85.1% of flights arrive on time here against a national 77.3%, a difference of 8 points in its favour. That is worth a A+ on this site's grading scale.
What time of day has the fewest delays on IAH to CLE?
The 5am–8am departure window is the strongest at 92.5% on time. The 2pm–5pm window is the weakest at 73.1%, 19 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 June delays on IAH to CLE?
June is the weakest month at 72.1% on time, compared with 95.1% in January. Across the year that is 23 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
- CLE to IAH — the return legseparate record
- George Bush Intercontinental (IAH) delay statistics
- Cleveland Hopkins International (CLE) delay statistics
- IAH to ORD, a related route75.1%
- ORD to CLE, a related route70.8%
- IAH to DFW, a related route76.4%
- United Airlines on-time record85.1%
- Why the first flight of the morning is statistically safest
- The best time of day to fly, according to 7.05 million flight records
Direction matters. IAH to CLE and CLE to IAH 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, September 2025 to August 2026. Last updated ; recomputed monthly. How this data is collected.