Carrier route record
UAPIT→IAD
United Airlines · Pittsburgh to Washington
- Flights
- 517
- Period
- September 2025 to August 2026
- Share of route
- 43%
- Carriers
- 2
Historical statistics for September 2025 to August 2026, not live status. For today’s flights, check with United Airlines.
United on PIT to IAD earns an A+. More than four flights in five arrive inside the 15-minute window the DOT uses to define an on-time arrival, which puts it 9 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 517 flights, with a median arrival 8 minutes early.
Set against the rest of the country, United's PIT to IAD record is 9 points better than the US average of 77.3%. That gap is worth roughly 87 fewer late arrivals for every thousand flights.
Key figures
On time
86.0%
Arrivals under 15 minutes late, of 513 completed flights
Avg delay
77 min
Across delayed arrivals only, not all flights
Cancelled
0.77%
National rate is 1.89%
Whole route
87.9%
Every carrier on PIT to IAD, 1,210 flights
These figures cover 517 flights between September 2025 and August 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.
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Carrier by carrier
United against every carrier on PIT to IAD
United flew 517 of the 1,210 flights on PIT to IAD, about 43% of it. Its 86.0% on time is 2 points worse than the route as a whole, which runs 87.9%. Ranked by on-time rate it is last of two carriers on the route, where the range runs from Republic at 89.4% to United at 86.0%.
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 |
|---|---|---|---|---|---|
| Republic Airways | 693 | 89.4% | 55 min | 1.88% | A |
| United Airlines (this page) | 517 | 86.0% | 77 min | 0.77% | A+ |
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 17 points, against half a point between the best and worst carrier.
- 5am–8am—
- 8am–11am203 flights93.1%
- 11am–2pm—
- 2pm–5pm154 flights75.7%
- 5pm–8pm—
- 8pm–5am160 flights86.8%
Scale runs 65% to 100%. Rows with fewer than 30 flights show a dash.
Book the morning departure. Flights leaving between 8am–11am arrive on time 93.1% of the time, against 75.7% for the afternoon window. That is 17 points of difference for no extra money, and it comes from the same aircraft having had no earlier flight to fall behind on. The 8am–11am window is the busiest, with 203 flights scheduled in it.
Across the year
United on PIT to IAD through the year
September is the best month on the calendar at 94.2% on time. Shoulder season thins the schedule and takes the summer weather with it, and the operation gets its margin back. February was the busiest month here, with 62 flights.
Across the week, Saturday is the strongest day at 94.1% on time and Sunday the weakest at 77.6%, a spread of 17 points.
Arrival by arrival
How late United on PIT to IAD runs when it is late
United on PIT to IAD often beats the schedule: 152 of 513 completed flights, 30%, arrived 15 minutes or more early. The 72 late arrivals split 31 under half an hour, 14 between 30 and 60 minutes, and 27 an hour or more.
- 15+ min early152 flights29.6%
- Within 15 min289 flights56.3%
- 15–29 min late31 flights6.0%
- 30–59 min late14 flights2.7%
- 1–2 hours late9 flights1.8%
- 2+ hours late18 flights3.5%
Scale runs 0% to 100%.
Share of 513 completed flights by arrival against schedule.
8 of 50 late departures made up the time and arrived on time, 16% of them. In the other direction, 30 flights left on time yet arrived 15 minutes late or more, so that delay built up after pushback: in the air, in a holding pattern or on the ground at IAD.
The worst days
Worst days for United on PIT to IAD
The latest arrival of the period was on 13 March 2026, 5 hours 59 minutes behind schedule; most of its delay minutes were filed as a late-arriving aircraft. Four of the five worst days fell in March 2026.
| Date | Arrived late by | Largest filed cause |
|---|---|---|
| 13 March 2026 | 5 hours 59 minutes | Late-arriving aircraft |
| 10 June 2026 | 5 hours | Late-arriving aircraft |
| 16 March 2026 | 4 hours 6 minutes | Late-arriving aircraft |
| 26 March 2026 | 4 hours 4 minutes | Late-arriving aircraft |
| 1 March 2026 | 4 hours 2 minutes | Late-arriving aircraft |
Delay causes
Why United runs late on this route
Late-arriving aircraft accounts for 59% of the 5,549 delay minutes carriers reported here, and the remaining four split what is left.
- 59%Late-arriving aircraft
- 30%National Airspace System
- 9%Carrier
- 2%Extreme weather
59% of delay minutes trace back to a late-arriving aircraft, meaning the plane was already behind before it got here. Across 5,549 reported delay minutes here, that single category outweighs weather by 36 to one. The split is drawn from 5,549 reported delay minutes.
The practical consequence: the 8am–11am departure is the one that starts clean. Its aircraft has no earlier leg to be late from, which is exactly why that window shows 93.1% on time here.
Cancellations are rare at 0.77%, 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
5.3% of arrivals land an hour or more late, close to the national 8.3%, so 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 182 miles this is a short hop, and stage length matters more than it looks. A flight this short spends under two hours in the air, which leaves almost nothing to claw back a late pushback with. Delay here is decided on the ground, in the turn, which is why the 8am–11am window matters as much as it does.
The return leg runs 87.5% on time across 517 flights, within 2 points of this direction. The two legs are scored separately because they usually differ; on this city pair they happen not to.
One caution: this is a thin sample. 517 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 PIT to IAD
Put together: treat all of this as provisional. 517 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 86.0% headline is the most reliable number on the page; the hour and month splits below it are built on a few dozen flights each. 513 completed flights over 12 months sit behind that.
Related
Where to go next
- PIT to IAD, every carrier
- United on IAD to PIT, the return leg
- Republic Airways on PIT to IAD89.4%
- United Airlines network-wide record
- Pittsburgh International (PIT) delay statistics
- Washington Dulles International (IAD) 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.