Carrier route record
UAIAH→PDX
United Airlines · Houston to Portland
- Flights
- 880
- Period
- July 2025 to June 2026
- Share of route
- 71%
- Carriers
- 2
Historical statistics for July 2025 to June 2026, not live status. For today’s flights, check with United Airlines.
United on IAH to PDX lands a B+, 4 points better than the national rate of 77.6%. About one flight in six arrives 15 minutes late or worse, and those flights are late by a little over an hour on average. That is a workable record, not a spotless one. That rests on 880 flights, with a median arrival 7 minutes early.
Set against the rest of the country, United's IAH to PDX record is 4 points better than the US average of 77.6%. That gap is worth roughly 44 fewer late arrivals for every thousand flights.
Key figures
On time
82.0%
Arrivals under 15 minutes late, of 872 completed flights
Avg delay
68 min
Across delayed arrivals only, not all flights
Cancelled
0.57%
National rate is 1.81%
Whole route
81.1%
Every carrier on IAH to PDX, 1,233 flights
These figures cover 880 flights between July 2025 and June 2026. The median arrival is 7 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 PDX
United flew 880 of the 1,233 flights on IAH to PDX, most of the route. Its 82.0% on time is about level with the route as a whole at 81.1%. Ranked by on-time rate it is first of two carriers on the route, where the range runs from United at 82.0% to Alaska at 78.7%. 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) | 880 | 82.0% | 68 min | 0.57% | B+ |
| Alaska Airlinesthin sample | 353 | 78.7% | 63 min | 1.13% | B |
Flight by flight
United flight numbers on IAH to PDX
Departure window
When United runs best on this route
Departure time is the single lever a traveller controls, and it moves the odds more than most people expect. Each bar below is the on-time rate for flights scheduled to leave inside that window, across 880 flights.
- 5am–8am—
- 8am–11am365 flights86.3%
- 11am–2pm—
- 2pm–5pm140 flights80.4%
- 5pm–8pm20 flights—
- 8pm–5am355 flights78.6%
Scale runs 70% to 90%. Rows with fewer than 30 flights show a dash.
The early departures do better, though not dramatically: 86.3% on time for the 8am–11am window against 78.6% for 8pm–5am. Worth taking if the schedule allows, not worth an extra connection. The 8am–11am window is the busiest, with 365 flights scheduled in it.
Across the year
United on IAH to PDX through the year
June is the worst month at 73.8% on time, 18 points below April, the best at 91.7%. 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. July was the busiest month here, with 92 flights.
Across the week, Sunday is the strongest day at 84.8% on time and Monday the weakest at 79.5%. 5 points is a smaller lever than departure hour, but it is free.
Delay causes
Why United runs late on this route
One category carries most of the weight here. Late-arriving aircraft accounts for 43% of the 11,000 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.
- 43%Late-arriving aircraft
- 32%Carrier
- 15%Extreme weather
- 10%National Airspace System
Extreme weather accounts for 15% 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 2.4 times the usual weather exposure. The split is drawn from 10,687 reported delay minutes.
43% 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 11,000 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 0.57%, 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
6.5% 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 a little over an hour, which a normal layover absorbs.
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 86.4% on time across 880 flights, 4 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 4 points of difference.
One caution: this is a thin sample. 880 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 IAH to PDX
Put together: treat all of this as provisional. 880 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 82.0% headline is the most reliable number on the page; the hour and month splits below it are built on a few dozen flights each. 872 completed flights over 12 months sit behind that.
Related
Where to go next
- IAH to PDX, every carrier
- United on PDX to IAH, the return leg
- Alaska Airlines on IAH to PDX78.7%
- United Airlines network-wide record
- George Bush Intercontinental (IAH) delay statistics
- Portland International (PDX) delay statistics
- Why the first flight of the morning is statistically safest
- 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.