Carrier route record
UAPDX→IAH
United Airlines · Portland to Houston
- Flights
- 855
- Period
- September 2025 to August 2026
- Share of route
- 71%
- Carriers
- 2
Historical statistics for September 2025 to August 2026, not live status. For today’s flights, check with United Airlines.
United on PDX 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 77.3%. When something does go wrong the average delay runs a little over an hour. That rests on 855 flights, with a median arrival 11 minutes early.
Set against the rest of the country, United's PDX to IAH record is 10 points better than the US average of 77.3%. That gap is worth roughly 98 fewer late arrivals for every thousand flights.
Key figures
On time
87.1%
Arrivals under 15 minutes late, of 851 completed flights
Avg delay
77 min
Across delayed arrivals only, not all flights
Cancelled
0.35%
National rate is 1.89%
Whole route
86.6%
Every carrier on PDX to IAH, 1,208 flights
These figures cover 855 flights between September 2025 and August 2026. The median arrival is 11 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
United against every carrier on PDX to IAH
United flew 855 of the 1,208 flights on PDX to IAH, most of the route. Its 87.1% on time is about level with the route as a whole at 86.6%. Ranked by on-time rate it is first of two carriers on the route, where the range runs from United at 87.1% to Alaska at 85.4%. One 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 |
|---|---|---|---|---|---|
| United Airlines (this page) | 855 | 87.1% | 77 min | 0.35% | A+ |
| Alaska Airlinesthin sample | 353 | 85.4% | 43 min | 0.85% | A+ |
Flight by flight
United flight numbers on PDX to IAH
Timetable by Aviasales, a Travelpayouts partner. Booking through it may earn this site a commission at no cost to you; it changes no figure here.
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 13 points, against half a point between the best and worst carrier.
- 5am–8am364 flights93.9%
- 8am–11am—
- 11am–2pm258 flights82.9%
- 2pm–5pm96 flights81.2%
- 5pm–8pm—
- 8pm–5am137 flights81.0%
Scale runs 75% to 100%. Rows with fewer than 30 flights show a dash.
Book the early departure. Flights leaving between 5am–8am arrive on time 93.9% of the time, against 81.0% for the overnight window. That is 13 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 364 flights scheduled in it.
Across the year
United on PDX to IAH through the year
July is the worst month at 70.6% on time, 26 points below August, the best at 96.7%. 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. May was the busiest month here, with 88 flights.
Across the week, Sunday is the strongest day at 91.1% on time and Friday the weakest at 84.0%, a spread of 7 points.
Arrival by arrival
How late United on PDX to IAH runs when it is late
United on PDX to IAH often beats the schedule: 315 of 851 completed flights, 37%, arrived 15 minutes or more early. The 110 late arrivals split 43 under half an hour, 26 between 30 and 60 minutes, and 41 an hour or more.
- 15+ min early315 flights37.0%
- Within 15 min426 flights50.1%
- 15–29 min late43 flights5.1%
- 30–59 min late26 flights3.1%
- 1–2 hours late21 flights2.5%
- 2+ hours late20 flights2.4%
Scale runs 0% to 100%.
Share of 851 completed flights by arrival against schedule.
28 of 109 late departures made up the time and arrived on time, 26% of them. 29 flights left on time and still arrived late.
The worst days
Worst days for United on PDX to IAH
The latest arrival of the period was on 19 December 2025, 11 hours 50 minutes behind schedule; most of its delay minutes were filed as carrier-caused (crew, maintenance, fuelling, baggage). On three of the five worst days the largest share was filed as a late-arriving aircraft.
| Date | Arrived late by | Largest filed cause |
|---|---|---|
| 19 December 2025 | 11 hours 50 minutes | Carrier |
| 30 July 2026 | 7 hours 22 minutes | Late-arriving aircraft |
| 24 November 2025 | 5 hours 28 minutes | Late-arriving aircraft |
| 23 June 2026 | 5 hours 14 minutes | Carrier |
| 16 June 2026 | 4 hours 33 minutes | Late-arriving aircraft |
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 8,467 reported delay minutes.
- 40%Carrier
- 37%Late-arriving aircraft
- 23%National Airspace System
- 1%Extreme weather
37% of delay minutes trace back to a late-arriving aircraft, meaning the plane was already behind before it got here. Across 8,467 reported delay minutes here, that single category outweighs weather by 37 to one. The split is drawn from 8,467 reported delay minutes.
The largest share of delay minutes, 40%, falls under carrier control: crew scheduling, maintenance, fuelling, baggage. It accounts for 3,355 of the 8,467 delay minutes reported here.
Cancellations are rare at 0.35%, 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 costs
Badly late arrivals are rare here: only 4.8% 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.
At 1,825 miles this is transcontinental flying, and long routes get a quiet structural advantage. Scheduled block time on a flight this length carries more padding in absolute minutes, so a twenty-minute late departure often still becomes an on-time arrival. Read the on-time rate here as slightly flattering next to a short-haul route with the same operational quality.
The return leg is a different operation and performs like one: it runs 82.3% on time across 856 flights, 5 points below 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.
One caution: this is a thin sample. 855 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.
What to do with this
Booking United on PDX to IAH
Put together: treat all of this as provisional. 855 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 87.1% headline is the most reliable number on the page; the hour and month splits below it are built on a few dozen flights each. 851 completed flights over 12 months sit behind that.
Related
Where to go next
- PDX to IAH, every carrier
- United on IAH to PDX, the return leg
- Alaska Airlines on PDX to IAH85.4%
- United Airlines network-wide record
- Portland International (PDX) delay statistics
- George Bush Intercontinental (IAH) delay statistics
- Why the first flight of the morning is statistically safest
- The best time of day to fly, according to 7.05 million flight records
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.