Carrier route record
UAORD→PIT
United Airlines · Chicago to Pittsburgh
- Flights
- 1,291
- Period
- July 2025 to June 2026
- Share of route
- 33%
- Carriers
- 5
Historical statistics for July 2025 to June 2026, not live status. For today’s flights, check with United Airlines.
United on ORD to PIT sits in the middle of the pack with a B. Close to three flights in four arrive on time by the DOT's definition, 2 points worse than the national rate of 77.6%. The late ones land about an hour behind schedule. That rests on 1,291 flights. The strongest carrier on the route with a full sample, Republic Airways, flew 1,628 at 81.4% on time.
The US average over the same twelve months is 77.6%, so there is little to separate United on ORD to PIT from the country as a whole. The variation that matters here is internal: which carrier, and what time of day.
Key figures
On time
75.8%
Arrivals under 15 minutes late, of 1,276 completed flights
Avg delay
66 min
Across delayed arrivals only, not all flights
Cancelled
1.01%
National rate is 1.81%
Whole route
74.9%
Every carrier on ORD to PIT, 3,948 flights
These figures cover 1,291 flights between July 2025 and June 2026. Beyond the headline rate, 8.4% of arrivals land a full hour or more behind schedule. That is the number that wrecks a connection, and it is not visible in an on-time percentage alone.
Carrier by carrier
United against every carrier on ORD to PIT
United flew 1,291 of the 3,948 flights on ORD to PIT, about 33% of it. Its 75.8% on time is about level with the route as a whole at 74.9%. Ranked by on-time rate it is number three of five carriers on the route, where the range runs from Envoy at 83.2% to American at 55.0%. Two of those carriers flew fewer than 365 flights here, so treat their positions as rough.
The choice of carrier is not cosmetic here. Republic Airways arrives on time 81.4% of the time; American Airlines manages 55.0%. Sample sizes sit next to every figure, because a two-point gap across 603 flights means less than a ten-point one.
| Airline | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| Envoy Airthin sample | 189 | 83.2% | 64 min | 2.12% | B |
| Republic Airways | 1,628 | 81.4% | 80 min | 2.27% | B |
| United Airlines (this page) | 1,291 | 75.8% | 66 min | 1.01% | B |
| SkyWest Airlinesthin sample | 237 | 68.5% | 66 min | 2.11% | C |
| American Airlines | 603 | 55.0% | 105 min | 2.99% | D |
The spread between Republic and American is 26 points, wide enough that it should decide the booking. On a hundred trips that is 26 more arrivals inside the on-time window.
Flight by flight
United flight numbers on ORD to PIT
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 21 points, against 26 points between the best and worst carrier. Each bar is the on-time rate for flights scheduled inside that window.
- 5am–8am281 flights87.1%
- 8am–11am326 flights80.6%
- 11am–2pm—
- 2pm–5pm326 flights72.9%
- 5pm–8pm349 flights66.3%
- 8pm–5am9 flights—
Scale runs 60% to 95%. Rows with fewer than 30 flights show a dash.
Book the early departure. Flights leaving between 5am–8am arrive on time 87.1% of the time, against 66.3% for the evening window. That is 21 points of difference for no extra money, and it comes from the same aircraft having had no earlier flight to fall behind on. The 5pm–8pm window is the busiest, with 349 flights scheduled in it.
Across the year
United on ORD to PIT through the year
January is the weak month at 66.0% on time, against 86.0% in September. Winter delays cluster: a single storm system can account for most of a month's shortfall, so an average December hides both very good weeks and genuinely unflyable days. May was the busiest month here, with 121 flights.
Across the week, Tuesday is the strongest day at 84.5% on time and Monday the weakest at 69.1%. 15 points is a smaller lever than departure hour, but it is free.
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 21,000 reported delay minutes.
- 39%Late-arriving aircraft
- 32%Carrier
- 18%National Airspace System
- 11%Extreme weather
39% 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 21,000 reported delay minutes here, that single category outweighs weather by 4 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 20,528 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 87.1% on time here.
Cancellations sit at 1.01% against a national 1.81%, which is ordinary. Diversions add another 0.15%.
Connections and stage length
What a delay here costs
8.4% 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 about an hour, which a normal layover absorbs.
At 413 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 5am–8am window matters as much as it does.
The return leg runs 77.9% on time across 1,290 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.
The sample behind these figures is 1,291 flights, enough that the headline rate is stable to within roughly a point. The hour-block and month splits divide that further, so read the thinner bars with more caution than the headline.
What to do with this
Booking United on ORD to PIT
Put together: the calendar is the biggest lever here, not the carrier or the hour. September runs 86.0% on time and January 66.0%, a swing of 20 points. If the dates move at all, move them out of January before you think about anything else. 1,276 completed flights over 12 months sit behind that.
Related
Where to go next
- ORD to PIT, every carrier
- United on PIT to ORD, the return leg
- Envoy Air on ORD to PIT83.2%
- Republic Airways on ORD to PIT81.4%
- SkyWest Airlines on ORD to PIT68.5%
- American Airlines on ORD to PIT55.0%
- United Airlines network-wide record
- Chicago O'Hare International (ORD) delay statistics
- Pittsburgh International (PIT) delay statistics
- Same route, different airline: where the carrier you pick matters most
- Why the first flight of the morning is statistically safest
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.