Carrier route record
UAORD→BWI
United Airlines · Chicago to Baltimore
- Flights
- 1,257
- Period
- September 2025 to August 2026
- Share of route
- 47%
- Carriers
- 8
Historical statistics for September 2025 to August 2026, not live status. For today’s flights, check with United Airlines.
United on ORD to BWI sits in the middle of the pack with a C. About seven flights in ten arrive on time by the DOT's definition, 7 points worse than the national rate of 77.3%. The late ones land about an hour behind schedule. That rests on 1,257 flights, with a median arrival 1 minute early.
The national on-time rate over the same period is 77.3%, so United on ORD to BWI runs 7 points behind the country as a whole. Across a thousand flights that is about 70 extra late arrivals.
Key figures
On time
70.3%
Arrivals under 15 minutes late, of 1,233 completed flights
Avg delay
65 min
Across delayed arrivals only, not all flights
Cancelled
1.59%
National rate is 1.89%
Whole route
72.3%
Every carrier on ORD to BWI, 2,679 flights
These figures cover 1,257 flights between September 2025 and August 2026. Beyond the headline rate, 9.9% of arrivals land a full hour or more behind schedule, against 8.3% nationally.
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Carrier by carrier
United against every carrier on ORD to BWI
United flew 1,257 of the 2,679 flights on ORD to BWI, about 47% of it. Its 70.3% on time is 2 points worse than the route as a whole, which runs 72.3%. Ranked by on-time rate it is number four of eight carriers on the route, where the range runs from Spirit at 100.0% to American at 57.7%. Six 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 |
|---|---|---|---|---|---|
| Spirit Airlinesthin sample | 9 | 100.0% | — | 0.00% | A+ |
| Southwest Airlinesthin sample | 62 | 80.6% | 53 min | 0.00% | B+ |
| Envoy Air | 841 | 77.3% | 63 min | 3.80% | B− |
| United Airlines (this page) | 1,257 | 70.3% | 65 min | 1.59% | C |
| Republic Airwaysthin sample | 336 | 69.6% | 89 min | 5.65% | C− |
| SkyWest Airlinesthin sample | 16 | 68.8% | 57 min | 0.00% | C+ |
| Frontier Airlinesthin sample | 132 | 64.3% | 92 min | 4.55% | D− |
| American Airlinesthin sample | 26 | 57.7% | 92 min | 0.00% | D+ |
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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 39 points, against half a point between the best and worst carrier.
- 5am–8am243 flights90.9%
- 8am–11am80 flights85.0%
- 11am–2pm229 flights73.5%
- 2pm–5pm253 flights67.2%
- 5pm–8pm373 flights57.5%
- 8pm–5am79 flights51.9%
Scale runs 45% to 95%.
The 8pm–5am window is where this operation falls apart: 51.9% on time, against 90.9% for the 5am–8am slot. By evening the aircraft flying these rotations have absorbed a full day of small delays and there is no slack left to recover in. The 5pm–8pm window is the busiest, with 373 flights scheduled in it.
Across the year
United on ORD to BWI through the year
September is the best month on the calendar at 81.1% on time. Shoulder season thins the schedule and takes the summer weather with it, and the operation gets its margin back. July was the busiest month here, with 148 flights.
Across the week, Tuesday is the strongest day at 74.2% on time and Sunday the weakest at 65.9%, a spread of 8 points.
Arrival by arrival
How late United on ORD to BWI runs when it is late
The 366 late arrivals split 141 under half an hour, 103 between 30 and 60 minutes, and 122 an hour or more.
- 15+ min early223 flights18.1%
- Within 15 min644 flights52.2%
- 15–29 min late141 flights11.4%
- 30–59 min late103 flights8.4%
- 1–2 hours late72 flights5.8%
- 2+ hours late50 flights4.1%
Scale runs 0% to 100%.
Share of 1,233 completed flights by arrival against schedule.
41 of 286 late departures made up the time and arrived on time, 14% of them. In the other direction, 121 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 BWI.
The worst days
Worst days for United on ORD to BWI
The latest arrival of the period was on 21 July 2026, 8 hours 49 minutes behind schedule; most of its delay minutes were filed as national airspace system delay. Three of the five worst days fell in July 2026.
| Date | Arrived late by | Largest filed cause |
|---|---|---|
| 21 July 2026 | 8 hours 49 minutes | National Airspace System |
| 16 August 2026 | 6 hours 52 minutes | National Airspace System |
| 27 July 2026 | 5 hours 25 minutes | Late-arriving aircraft |
| 30 January 2026 | 5 hours 15 minutes | Late-arriving aircraft |
| 5 July 2026 | 5 hours 6 minutes | National Airspace System |
Delay causes
Why United runs late on this route
Late-arriving aircraft accounts for 48% of the 24,000 delay minutes carriers reported here, and the remaining four split what is left.
- 48%Late-arriving aircraft
- 29%National Airspace System
- 19%Carrier
- 4%Extreme weather
48% of delay minutes trace back to a late-arriving aircraft, meaning the plane was already behind before it got here. Across 24,000 reported delay minutes here, that single category outweighs weather by 11 to one. The split is drawn from 23,645 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 90.9% on time here.
Cancellations sit at 1.59% against a national 1.89%, which is ordinary. Diversions add another 0.32%.
Connections and stage length
What a delay here costs
9.9% of arrivals land a full hour or more behind schedule, against 8.3% nationally. Ninety minutes is the honest minimum for a connection here, and two hours if the onward flight is on a separate ticket.
The 622 miles between these two airports put this in the middle of the US network, around two and a half to three hours of block time. That is enough cruise to absorb a ten-minute late pushback and not enough to absorb thirty.
The return leg is a different operation and performs like one: it runs 74.3% on time across 1,253 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.
The sample behind these figures is 1,257 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 BWI
Put together: the calendar is the biggest lever here, not the carrier or the hour. September runs 81.1% on time and March 52.5%, a swing of 29 points. If the dates move at all, move them out of March before you think about anything else. 1,233 completed flights over 12 months sit behind that.
Related
Where to go next
- ORD to BWI, every carrier
- United on BWI to ORD, the return leg
- Envoy Air on ORD to BWI77.3%
- Republic Airways on ORD to BWI69.6%
- Frontier Airlines on ORD to BWI64.3%
- United Airlines network-wide record
- Chicago O'Hare International (ORD) delay statistics
- Baltimore/Washington International Thurgood Marshall (BWI) 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.