Carrier route record
UABWI→ORD
United Airlines · Baltimore to Chicago
- Flights
- 1,148
- 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 BWI to ORD sits in the middle of the pack with a B. Close to three flights in four arrive on time by the DOT's definition, 3 points worse than the national rate of 77.6%. The late ones land an hour and a half behind schedule. That rests on 1,148 flights, with a median arrival 3 minutes early.
The US average over the same twelve months is 77.6%, so there is little to separate United on BWI to ORD from the country as a whole. The variation that matters here is internal: which carrier, and what time of day.
Key figures
On time
75.1%
Arrivals under 15 minutes late, of 1,130 completed flights
Avg delay
88 min
Across delayed arrivals only, not all flights
Cancelled
1.31%
National rate is 1.81%
Whole route
74.9%
Every carrier on BWI to ORD, 2,690 flights
These figures cover 1,148 flights between July 2025 and June 2026. Beyond the headline rate, 8.3% 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 BWI to ORD
United flew 1,148 of the 2,690 flights on BWI to ORD, about 43% of it. Its 75.1% on time is about level with the route as a whole at 74.9%. Ranked by on-time rate it is number four of eight carriers on the route, where the range runs from Southwest at 85.4% to American at 38.5%. 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 |
|---|---|---|---|---|---|
| Southwest Airlinesthin sample | 124 | 85.4% | 50 min | 0.81% | A+ |
| Republic Airwaysthin sample | 274 | 83.0% | 88 min | 2.92% | B |
| Spirit Airlinesthin sample | 23 | 82.6% | 96 min | 0.00% | B+ |
| United Airlines (this page) | 1,148 | 75.1% | 88 min | 1.31% | B |
| Envoy Air | 903 | 74.7% | 85 min | 3.77% | C− |
| Frontier Airlinesthin sample | 150 | 64.3% | 177 min | 4.00% | D− |
| SkyWest Airlinesthin sample | 42 | 43.9% | 158 min | 2.38% | F |
| American Airlinesthin sample | 26 | 38.5% | 81 min | 0.00% | F+ |
Flight by flight
United flight numbers on BWI to ORD
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 36 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–8am299 flights91.2%
- 8am–11am154 flights84.1%
- 11am–2pm207 flights88.7%
- 2pm–5pm53 flights67.3%
- 5pm–8pm433 flights55.7%
- 8pm–5am2 flights—
Scale runs 45% to 95%. Rows with fewer than 30 flights show a dash.
The 5pm–8pm window is where this operation falls apart: 55.7% on time, against 91.2% 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 433 flights scheduled in it.
Across the year
United on BWI to ORD through the year
December is the weak month at 67.0% on time, against 81.0% 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. June was the busiest month here, with 146 flights.
Across the week, Tuesday is the strongest day at 77.7% on time and Sunday the weakest at 72.0%. 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. National Airspace System accounts for 44% of the 25,000 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.
- 44%National Airspace System
- 25%Late-arriving aircraft
- 18%Carrier
- 13%Extreme weather
Extreme weather accounts for 13% of delay minutes, well above the single-digit share typical across the system. Weather delays are lumpy: they arrive as whole bad days rather than as a steady drag, so the monthly strip above is the more useful view of the risk. The national share is 6%, so this operation carries roughly 2.1 times the usual weather exposure. The split is drawn from 24,791 reported delay minutes.
44% of delay minutes are charged to the National Airspace System: air traffic volume, runway configuration, ground stops. No carrier can price its way out of that, which is why airport choice moves the number here more than carrier choice does. That is 11,000 minutes out of 25,000, against a national NAS share of 21%.
Cancellations sit at 1.31% against a national 1.81%, which is ordinary. Diversions add another 0.26%.
Connections and stage length
What a delay here costs
8.3% 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 an hour and a half, which a normal layover absorbs.
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 71.1% on time across 1,151 flights, 4 points below 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 1,148 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 BWI to ORD
Put together: the calendar is the biggest lever here, not the carrier or the hour. September runs 81.0% on time and December 67.0%, a swing of 14 points. If the dates move at all, move them out of December before you think about anything else. 1,130 completed flights over 12 months sit behind that.
Related
Where to go next
- BWI to ORD, every carrier
- United on ORD to BWI, the return leg
- Southwest Airlines on BWI to ORD85.4%
- Republic Airways on BWI to ORD83.0%
- Envoy Air on BWI to ORD74.7%
- Frontier Airlines on BWI to ORD64.3%
- United Airlines network-wide record
- Baltimore/Washington International Thurgood Marshall (BWI) delay statistics
- Chicago O'Hare International (ORD) delay statistics
- The best time of day to fly, according to 7.04 million flight records
- Connecting flights: how much buffer the data says you need
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.