Carrier route record
UAPHX→IAD
United Airlines · Phoenix to Washington
- Flights
- 704
- Period
- September 2025 to August 2026
- Share of route
- 72%
- Carriers
- 2
Historical statistics for September 2025 to August 2026, not live status. For today’s flights, check with United Airlines.
United on PHX to IAD 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 14 points better than the national rate of 77.3%. When something does go wrong the average delay runs about an hour. That rests on 704 flights, with a median arrival 10 minutes early.
Set against the rest of the country, United's PHX to IAD record is 14 points better than the US average of 77.3%. That gap is worth roughly 135 fewer late arrivals for every thousand flights.
Key figures
On time
90.8%
Arrivals under 15 minutes late, of 695 completed flights
Avg delay
57 min
Across delayed arrivals only, not all flights
Cancelled
0.71%
National rate is 1.89%
Whole route
86.1%
Every carrier on PHX to IAD, 979 flights
These figures cover 704 flights between September 2025 and August 2026. The median arrival is 10 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 PHX to IAD
United flew 704 of the 979 flights on PHX to IAD, most of the route. Its 90.8% on time is 5 points better than the route as a whole, which runs 86.1%. Ranked by on-time rate it is first of two carriers on the route, where the range runs from United at 90.8% to Southwest at 74.3%. 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) | 704 | 90.8% | 57 min | 0.71% | A+ |
| Southwest Airlinesthin sample | 275 | 74.3% | 35 min | 0.36% | C+ |
Flight by flight
United flight numbers on PHX to IAD
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 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 704 flights.
- 5am–8am74 flights94.5%
- 8am–11am291 flights89.6%
- 11am–2pm120 flights89.9%
- 2pm–5pm129 flights91.4%
- 5pm–8pm—
- 8pm–5am90 flights92.0%
Scale runs 80% to 100%. Rows with fewer than 30 flights show a dash.
The early departures do better, though not dramatically: 94.5% on time for the 5am–8am window against 89.6% for 8am–11am. Worth taking if the schedule allows, not worth an extra connection. The 8am–11am window is the busiest, with 291 flights scheduled in it.
Across the year
United on PHX to IAD through the year
August is the worst month at 80.0% on time, 20 points below January, the best at 100.0%. 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 86 flights.
Across the week, Wednesday is the strongest day at 93.9% on time and Sunday the weakest at 86.1%, a spread of 8 points.
Arrival by arrival
How late United on PHX to IAD runs when it is late
United on PHX to IAD often beats the schedule: 267 of 695 completed flights, 38%, arrived 15 minutes or more early. The 64 late arrivals split 29 under half an hour, 16 between 30 and 60 minutes, and 19 an hour or more.
- 15+ min early267 flights38.4%
- Within 15 min364 flights52.4%
- 15–29 min late29 flights4.2%
- 30–59 min late16 flights2.3%
- 1–2 hours late12 flights1.7%
- 2+ hours late7 flights1.0%
Scale runs 0% to 100%.
Share of 695 completed flights by arrival against schedule.
A late pushback is often recovered here: of 75 departures that left 15 minutes late or more, 30 still arrived on time. 19 flights left on time and still arrived late.
The worst days
Worst days for United on PHX to IAD
The latest arrival of the period was on 22 November 2025, 5 hours behind schedule; most of its delay minutes were filed as a late-arriving aircraft. On three of the five worst days the largest share was filed as carrier-caused (crew, maintenance, fuelling, baggage).
| Date | Arrived late by | Largest filed cause |
|---|---|---|
| 22 November 2025 | 5 hours | Late-arriving aircraft |
| 3 October 2025 | 3 hours 54 minutes | Carrier |
| 14 June 2026 | 3 hours 45 minutes | Carrier |
| 26 September 2025 | 2 hours 55 minutes | Late-arriving aircraft |
| 4 May 2026 | 2 hours 50 minutes | Carrier |
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 3,631 reported delay minutes.
- 42%Carrier
- 31%Late-arriving aircraft
- 25%National Airspace System
- 3%Extreme weather
The largest share of delay minutes, 42%, falls under carrier control: crew scheduling, maintenance, fuelling, baggage. It accounts for 1,519 of the 3,631 delay minutes reported here. The split is drawn from 3,631 reported delay minutes.
The practical consequence: the 5am–8am departure is the one that starts clean. Its aircraft has no earlier leg to be late from, which is exactly why that window shows 94.5% on time here.
Cancellations are rare at 0.71%, 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 2.7% 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 1,956 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 85.2% on time across 704 flights, 6 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 6 points of difference.
One caution: this is a thin sample. 704 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 PHX to IAD
Put together: treat all of this as provisional. 704 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 90.8% headline is the most reliable number on the page; the hour and month splits below it are built on a few dozen flights each. 695 completed flights over 12 months sit behind that.
Related
Where to go next
- PHX to IAD, every carrier
- United on IAD to PHX, the return leg
- Southwest Airlines on PHX to IAD74.3%
- United Airlines network-wide record
- Phoenix Sky Harbor International (PHX) delay statistics
- Washington Dulles International (IAD) delay statistics
- Worst months to fly in the US, ranked by the data
- How to read this site: grades, sample sizes, and honest caveats
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.