Carrier route record
UALAX→IAH
United Airlines · Los Angeles to Houston
- Flights
- 3,415
- Period
- July 2025 to June 2026
- Share of route
- 65%
- Carriers
- 5
Historical statistics for July 2025 to June 2026, not live status. For today’s flights, check with United Airlines.
United on LAX to IAH earns an A+. Close to nine flights in ten arrive inside the 15-minute window the DOT uses to define an on-time arrival, which puts it 10 points better than the national rate of 77.6%. When something does go wrong the average delay runs about an hour. That rests on 3,415 flights. The strongest carrier on the route with a full sample, Delta Air Lines, flew 645 at 86.1% on time.
Set against the rest of the country, United's LAX to IAH record is 10 points better than the US average of 77.6%. That gap is worth roughly 95 fewer late arrivals for every thousand flights.
Key figures
On time
87.1%
Arrivals under 15 minutes late, of 3,391 completed flights
Avg delay
55 min
Across delayed arrivals only, not all flights
Cancelled
0.26%
National rate is 1.81%
Whole route
84.6%
Every carrier on LAX to IAH, 5,255 flights
These figures cover 3,415 flights between July 2025 and June 2026. The median arrival is 9 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
United against every carrier on LAX to IAH
United flew 3,415 of the 5,255 flights on LAX to IAH, most of the route. Its 87.1% on time is 3 points better than the route as a whole, which runs 84.6%. Ranked by on-time rate it is first of five carriers on the route, where the range runs from United at 87.1% to Frontier at 68.2%. One of those carriers flew fewer than 365 flights here, so treat their positions as rough.
The choice of carrier is not cosmetic here. Delta Air Lines arrives on time 86.1% of the time; Spirit Airlines manages 77.5%. Sample sizes sit next to every figure, because a two-point gap across 455 flights means less than a ten-point one.
| Airline | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| United Airlines (this page) | 3,415 | 87.1% | 55 min | 0.26% | A+ |
| Delta Air Lines | 645 | 86.1% | 73 min | 1.09% | A |
| SkyWest Airlines | 408 | 82.0% | 68 min | 0.49% | B+ |
| Spirit Airlines | 455 | 77.5% | 83 min | 1.32% | B |
| Frontier Airlinesthin sample | 332 | 68.2% | 71 min | 2.11% | C |
Delta leads Spirit by 9 points. Real, but small enough that a better departure time on the weaker carrier can outweigh it.
Flight by flight
United flight numbers on LAX to IAH
Departure window
When United runs best on this route
Departure time matters more here than the choice of carrier. The gap between the best and worst window is 16 points, against 9 points between the best and worst carrier. Each bar is the on-time rate for flights scheduled inside that window.
- 5am–8am695 flights94.1%
- 8am–11am739 flights89.6%
- 11am–2pm726 flights78.3%
- 2pm–5pm336 flights84.7%
- 5pm–8pm368 flights83.4%
- 8pm–5am551 flights90.6%
Scale runs 70% to 100%. Rows with fewer than 30 flights show a dash.
The weak window here is the middle of the day, not the evening: 11am–2pm runs 78.3% on time against 94.1% for 5am–8am. That shape usually means a departure bank rather than an accumulating delay, so the recovery later in the afternoon is real rather than noise. The 8am–11am window is the busiest, with 739 flights scheduled in it.
Across the year
United on LAX to IAH through the year
October is the best month on the calendar at 94.0% on time. Shoulder season thins the schedule and takes the summer weather with it, and the operation gets its margin back. May was the busiest month here, with 303 flights.
Across the week, Thursday is the strongest day at 88.8% on time and Saturday the weakest at 84.5%. 4 points is a smaller lever than departure hour, but it is free.
Delay causes
Why United runs late on this route
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 24,000 reported delay minutes.
- 34%Carrier
- 34%National Airspace System
- 30%Late-arriving aircraft
- 2%Extreme weather
The largest share of delay minutes, 34%, 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 8,267 of the 24,000 delay minutes reported here. The split is drawn from 24,117 reported delay minutes.
34% 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 8,154 minutes out of 24,000, against a national NAS share of 21%.
Cancellations are rare at 0.26%, 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 costs
Badly late arrivals are rare here: only 3.5% land an hour or more behind schedule, against 8.1% 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 1,379 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 84.4% on time across 3,416 flights, within 3 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 3,415 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 United on LAX to IAH
Put together: the calendar is the biggest lever here, not the carrier or the hour. October runs 94.0% on time and November 79.9%, a swing of 14 points. If the dates move at all, move them out of November before you think about anything else. 3,391 completed flights over 12 months sit behind that.
Related
Where to go next
- LAX to IAH, every carrier
- United on IAH to LAX, the return leg
- Delta Air Lines on LAX to IAH86.1%
- SkyWest Airlines on LAX to IAH82.0%
- Spirit Airlines on LAX to IAH77.5%
- Frontier Airlines on LAX to IAH68.2%
- United Airlines network-wide record
- Los Angeles International (LAX) delay statistics
- George Bush Intercontinental (IAH) delay statistics
- The best time of day to fly, according to 7.04 million flight records
- Worst months to fly in the US, ranked by the data
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.