Route reliability record
ORD→BWI
Chicago to Baltimore
- Flights
- 2,696
- Period
- July 2025 to June 2026
- Distance
- 622 mi
- Carriers
- 8
This route sits in the middle of the pack with a C. About seven flights in ten arrive on time by the DOT's definition, 6 points worse than the national rate of 77.6%. The late ones land about an hour behind schedule. That rests on 2,696 flights, of which Envoy Air flew 903 at 76.4% on time.
The national on-time rate over the same period is 77.6%, so this route runs 6 points behind the country as a whole. Across a thousand flights that is about 57 extra late arrivals.
Key figures
On time
71.9%
Arrivals under 15 minutes late, of 2,622 completed flights
Avg delay
67 min
Across delayed arrivals only, not all flights
Cancelled
2.56%
National rate is 1.81%
Best carrier
Envoy
76.4% on time across 903 flights
These figures cover 2,696 flights between July 2025 and June 2026. Beyond the headline rate, 10.8% 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
Which airline is most reliable on ORD to BWI
The two carriers here are closely matched: 5 points separate the best from the worst. At that spread, schedule and price are better tie-breakers than reliability. Sample sizes are shown so you can see which rows are worth weighing.
| 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 | 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+ |
Envoy Air cancels 3.8% of what it schedules here, the highest in the table. A cancelled flight never appears in an on-time rate, so read that column alongside the punctuality one rather than after it.
Departure window
The best time of day to leave
Departure time matters more here than the choice of carrier. The gap between the best and worst window is 27 points, against 5 points between the best and worst carrier. Each bar is the on-time rate for flights scheduled inside that window.
- 5am–8am351 flights87.2%
- 8am–11am416 flights84.0%
- 11am–2pm327 flights70.5%
- 2pm–5pm763 flights68.8%
- 5pm–8pm496 flights60.1%
- 8pm–5am343 flights66.6%
Scale runs 50% to 95%. Rows with fewer than 30 flights show a dash.
The 5pm–8pm window is where this operation falls apart: 60.1% on time, against 87.2% 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 2pm–5pm window is the busiest, with 763 flights scheduled in it.
Across the year
When delays peak on this route
This route's year swings by 19 points from best month to worst, which is wide. An annual average tells you very little about the week you are actually flying, so read the strip rather than the headline if your dates are fixed.
December is the weak month at 61.1% on time, against 80.6% 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 274 flights.
Across the week, Saturday is the strongest day at 76.8% on time and Wednesday the weakest at 68.1%. 9 points is a smaller lever than departure hour, but it is free.
Delay causes
Why this route gets delayed
One category carries most of the weight here. Late-arriving aircraft accounts for 46% of the 49,000 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.
- 46%Late-arriving aircraft
- 23%Carrier
- 21%National Airspace System
- 10%Extreme weather
- 0%Security
46% 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 49,000 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 49,158 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 87.2% on time here.
Cancellations run at 2.56%, against 1.81% nationally. That is about one flight in 40 cancelled outright. A cancelled flight is invisible in every on-time figure on this page, so the punctuality numbers above describe only the flights that actually operated.
Connections and stage length
What a delay here actually costs
For anyone connecting, the number to weigh is not the on-time rate but the tail behind it. 10.8% 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 74.9% on time across 2,690 flights, 3 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 3 points of difference.
The sample behind these figures is 2,696 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 this route
Put together: the calendar is the biggest lever here, not the carrier or the hour. September runs 80.6% on time and December 61.1%, a swing of 19 points. If the dates move at all, move them out of December before you think about anything else. 2,622 completed flights over 12 months sit behind that.
Common questions
ORD to BWI questions
How often is ORD to BWI delayed?
Roughly one flight in four arrive at least 15 minutes late, which is the Department of Transportation's definition of a delayed arrival. That works out to 28.1% of the 2,696 flights in this analysis, against 22.4% nationally. Delayed flights are late by about an hour on average.
Which airline is most reliable on ORD to BWI?
Envoy Air leads at 76.4% on time across 903 flights. United Airlines is at the other end on 71.1%, a gap of 5 points. Sample size matters as much as the percentage: a rate built from a few hundred flights moves around far more than one built from ten thousand.
What time of day has the fewest delays on ORD to BWI?
The 5am–8am departure window is the strongest at 87.2% on time. The 5pm–8pm window is the weakest at 60.1%, 27 points behind. Later departures inherit delays from earlier flights the same aircraft has already flown, which is why the curve slopes the way it does.
How bad are December delays on ORD to BWI?
December is the weakest month at 61.1% on time, compared with 80.6% in September. Across the year that is 19 points between the best and worst months. Moving flexible dates out of that month is one of the few things that reliably helps.
Related
Where to go next
- BWI to ORD — the return legseparate record
- Chicago O'Hare International (ORD) delay statistics
- Baltimore/Washington International Thurgood Marshall (BWI) delay statistics
- Spirit Airlines on-time record77.8%
- Envoy Air on-time record76.4%
- United Airlines on-time record71.1%
- Why the first flight of the morning is statistically safest
- The best time of day to fly, according to 7.04 million flight records
Direction matters. ORD to BWI and BWI to ORD are scored separately because they are separate operations, with different departure banks and different aircraft. Compare the return leg.
Source: US DOT Bureau of Transportation Statistics, on-time performance data, July 2025 to June 2026. Updated monthly. How this data is collected.