Carrier route record
UAORD→BWI
United Airlines · Chicago to Baltimore
- Flights
- 1,151
- Period
- July 2025 to June 2026
- Share of route
- 43%
- Carriers
- 8
Historical statistics for July 2025 to June 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 77.6%. The late ones land about an hour behind schedule. That rests on 1,151 flights, with a median arrival 1 minute early.
The national on-time rate over the same period is 77.6%, so United on ORD to BWI runs 7 points behind the country as a whole. Across a thousand flights that is about 65 extra late arrivals.
Key figures
On time
71.1%
Arrivals under 15 minutes late, of 1,132 completed flights
Avg delay
61 min
Across delayed arrivals only, not all flights
Cancelled
1.39%
National rate is 1.81%
Whole route
71.9%
Every carrier on ORD to BWI, 2,696 flights
These figures cover 1,151 flights between July 2025 and June 2026. Beyond the headline rate, 10.1% 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 BWI
United flew 1,151 of the 2,696 flights on ORD to BWI, about 43% of it. Its 71.1% on time is about level with the route as a whole at 71.9%. Ranked by on-time rate it is number three of eight carriers on the route, where the range runs from Spirit at 77.8% 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 | 27 | 77.8% | 60 min | 0.00% | B+ |
| Envoy Air | 903 | 76.4% | 62 min | 3.77% | B− |
| United Airlines (this page) | 1,151 | 71.1% | 61 min | 1.39% | C |
| Republic Airwaysthin sample | 274 | 70.5% | 80 min | 3.65% | C− |
| Frontier Airlinesthin sample | 150 | 65.3% | 80 min | 4.00% | C− |
| SkyWest Airlinesthin sample | 41 | 64.1% | 81 min | 2.44% | D |
| Southwest Airlinesthin sample | 124 | 63.1% | 84 min | 1.61% | D |
| American Airlinesthin sample | 26 | 57.7% | 92 min | 0.00% | D+ |
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 38 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–8am240 flights89.9%
- 8am–11am121 flights83.5%
- 11am–2pm188 flights72.4%
- 2pm–5pm197 flights68.4%
- 5pm–8pm355 flights57.3%
- 8pm–5am50 flights52.1%
Scale runs 45% to 95%. Rows with fewer than 30 flights show a dash.
The 8pm–5am window is where this operation falls apart: 52.1% on time, against 89.9% 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 355 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. June was the busiest month here, with 146 flights.
Across the week, Thursday is the strongest day at 74.7% on time and Wednesday the weakest at 68.5%. 6 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 50% of the 20,000 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.
- 50%Late-arriving aircraft
- 24%Carrier
- 21%National Airspace System
- 5%Extreme weather
50% 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 20,000 reported delay minutes here, that single category outweighs weather by 9 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 19,929 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 89.9% on time here.
Cancellations sit at 1.39% against a national 1.81%, which is ordinary. Diversions add another 0.26%.
Connections and stage length
What a delay here costs
For anyone connecting, the number to weigh is not the on-time rate but the tail behind it. 10.1% of arrivals land a full hour or more behind schedule, against 8.1% nationally. A 45-minute layover does not survive that, and no amount of walking quickly changes it. Ninety minutes is the honest minimum 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. It is also long enough that the aircraft usually flies three or four legs a day rather than six, which slows how fast delay compounds.
The return leg is a different operation and performs like one: it runs 75.1% on time across 1,148 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 1,151 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. 1,132 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 BWI76.4%
- Republic Airways on ORD to BWI70.5%
- Frontier Airlines on ORD to BWI65.3%
- Southwest Airlines on ORD to BWI63.1%
- 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 7.04 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.