Carrier route record
UAIAH→PHX
United Airlines · Houston to Phoenix
- Flights
- 1,784
- Period
- July 2025 to June 2026
- Share of route
- 61%
- Carriers
- 5
Historical statistics for July 2025 to June 2026, not live status. For today’s flights, check with United Airlines.
United on IAH to PHX 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 1,784 flights, with a median arrival 8 minutes early.
The US average over the same twelve months is 77.6%, so there is little to separate United on IAH to PHX from the country as a whole. The variation that matters here is internal: which carrier, and what time of day.
Key figures
On time
80.0%
Arrivals under 15 minutes late, of 1,776 completed flights
Avg delay
64 min
Across delayed arrivals only, not all flights
Cancelled
0.34%
National rate is 1.81%
Whole route
78.7%
Every carrier on IAH to PHX, 2,930 flights
These figures cover 1,784 flights between July 2025 and June 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.
Carrier by carrier
United against every carrier on IAH to PHX
United flew 1,784 of the 2,930 flights on IAH to PHX, most of the route. Its 80.0% on time is about level with the route as a whole at 78.7%. Ranked by on-time rate it is number three of five carriers on the route, where the range runs from Envoy at 83.3% to Frontier at 68.5%. Three of those carriers flew fewer than 365 flights here, so treat their positions as rough.
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 |
|---|---|---|---|---|---|
| Envoy Airthin sample | 67 | 83.3% | 98 min | 1.49% | B |
| American Airlines | 622 | 81.6% | 168 min | 1.45% | B |
| United Airlines (this page) | 1,784 | 80.0% | 64 min | 0.34% | B+ |
| SkyWest Airlinesthin sample | 180 | 69.7% | 76 min | 2.78% | C |
| Frontier Airlinesthin sample | 277 | 68.5% | 74 min | 1.08% | C |
Flight by flight
United flight numbers on IAH to PHX
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 27 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–8am175 flights94.3%
- 8am–11am365 flights84.5%
- 11am–2pm130 flights90.0%
- 2pm–5pm527 flights80.2%
- 5pm–8pm203 flights75.4%
- 8pm–5am384 flights67.7%
Scale runs 60% to 100%. Rows with fewer than 30 flights show a dash.
Book the early departure. Flights leaving between 5am–8am arrive on time 94.3% of the time, against 67.7% for the overnight window. That is 27 points of difference for no extra money, and it comes from the same aircraft having had no earlier flight to fall behind on. The 2pm–5pm window is the busiest, with 527 flights scheduled in it.
Across the year
United on IAH to PHX through the year
June is the worst month at 63.6% on time, 32 points below February, the best at 95.4%. 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 179 flights.
Across the week, Tuesday is the strongest day at 86.7% on time and Sunday the weakest at 73.6%. 13 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 23,000 reported delay minutes.
- 37%Late-arriving aircraft
- 29%Carrier
- 22%National Airspace System
- 12%Extreme weather
Extreme weather accounts for 12% of delay minutes, well above the single-digit share typical across the system. Weather delays are lumpy: they arrive as whole bad days rather than as a steady drag, so the monthly strip above is the more useful view of the risk. The national share is 6%, so this operation carries roughly 1.9 times the usual weather exposure. The split is drawn from 22,591 reported delay minutes.
37% 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 23,000 reported delay minutes here, that single category outweighs weather by 3 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.
Cancellations are rare at 0.34%, 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
7.5% 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.
The 1,009 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 is a different operation and performs like one: it runs 84.6% on time across 1,780 flights, 5 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 5 points of difference.
The sample behind these figures is 1,784 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 IAH to PHX
Put together: the calendar is the biggest lever here, not the carrier or the hour. February runs 95.4% on time and June 63.6%, a swing of 32 points. If the dates move at all, move them out of June before you think about anything else. 1,776 completed flights over 12 months sit behind that.
Related
Where to go next
- IAH to PHX, every carrier
- United on PHX to IAH, the return leg
- American Airlines on IAH to PHX81.6%
- SkyWest Airlines on IAH to PHX69.7%
- Frontier Airlines on IAH to PHX68.5%
- United Airlines network-wide record
- George Bush Intercontinental (IAH) delay statistics
- Phoenix Sky Harbor International (PHX) delay statistics
- Why the first flight of the morning is statistically safest
- The best time of day to fly, according to 7.04 million flight records
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.