Carrier route record
UAPIT→IAD
United Airlines · Pittsburgh to Washington
- Flights
- 499
- Period
- July 2025 to June 2026
- Share of route
- 39%
- Carriers
- 2
Historical statistics for July 2025 to June 2026, not live status. For today’s flights, check with United Airlines.
United on PIT 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 11 points better than the national rate of 77.6%. When something does go wrong the average delay runs a little over an hour. That rests on 499 flights, with a median arrival 9 minutes early.
Set against the rest of the country, United's PIT to IAD record is 11 points better than the US average of 77.6%. That gap is worth roughly 105 fewer late arrivals for every thousand flights.
Key figures
On time
88.1%
Arrivals under 15 minutes late, of 495 completed flights
Avg delay
72 min
Across delayed arrivals only, not all flights
Cancelled
0.80%
National rate is 1.81%
Whole route
88.3%
Every carrier on PIT to IAD, 1,266 flights
These figures cover 499 flights between July 2025 and June 2026. The median arrival is 9 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 PIT to IAD
United flew 499 of the 1,266 flights on PIT to IAD, about 39% of it. Its 88.1% on time is about level with the route as a whole at 88.3%. Ranked by on-time rate it is last of two carriers on the route, where the range runs from Republic at 88.4% to United at 88.1%.
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 | 767 | 88.4% | 50 min | 1.83% | A |
| United Airlines (this page) | 499 | 88.1% | 72 min | 0.80% | A+ |
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 18 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–8am—
- 8am–11am228 flights93.8%
- 11am–2pm—
- 2pm–5pm98 flights76.3%
- 5pm–8pm—
- 8pm–5am173 flights87.2%
Scale runs 70% to 100%. Rows with fewer than 30 flights show a dash.
Book the morning departure. Flights leaving between 8am–11am arrive on time 93.8% of the time, against 76.3% for the afternoon window. That is 18 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 228 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, Tuesday is the strongest day at 95.1% on time and Monday the weakest at 81.8%. 13 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 70% of the 4,251 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.
- 70%Late-arriving aircraft
- 21%National Airspace System
- 7%Carrier
- 2%Extreme weather
70% 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 4,251 reported delay minutes here, that single category outweighs weather by 42 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. The split is drawn from 4,251 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 93.8% on time here.
Cancellations are rare at 0.80%, 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
Badly late arrivals are rare here: only 4.0% land an hour or more behind schedule, against 8.1% 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 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 87.2% on time across 499 flights, within about a point 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. 499 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. 499 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 88.1% headline is the most reliable number on the page; the hour and month splits below it are built on a few dozen flights each. 495 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 IAD88.4%
- 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 7.04 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.