Carrier route record
WNBWI→ORD
Southwest Airlines · Baltimore to Chicago
- Flights
- 124
- Period
- July 2025 to June 2026
- Share of route
- 5%
- Carriers
- 8
Historical statistics for July 2025 to June 2026, not live status. For today’s flights, check with Southwest Airlines.
Southwest on BWI to ORD earns an A+. More than four flights in five arrive inside the 15-minute window the DOT uses to define an on-time arrival, which puts it 8 points better than the national rate of 77.6%. When something does go wrong the average delay runs about 50 minutes. That rests on 124 flights. The strongest carrier on the route with a full sample, United Airlines, flew 1,148 at 75.1% on time.
Set against the rest of the country, Southwest's BWI to ORD record is 8 points better than the US average of 77.6%. That gap is worth roughly 78 fewer late arrivals for every thousand flights.
Key figures
On time
85.4%
Arrivals under 15 minutes late, of 123 completed flights
Avg delay
50 min
Across delayed arrivals only, not all flights
Cancelled
0.81%
National rate is 1.81%
Whole route
74.9%
Every carrier on BWI to ORD, 2,690 flights
These figures cover 124 flights between July 2025 and June 2026. The median arrival is 11 minutes early, which is the part an average hides: most flights here are fine, and the on-time rate is decided by a tail of badly late ones. On-time means under 15 minutes late, the DOT's own threshold.
Carrier by carrier
Southwest against every carrier on BWI to ORD
Southwest flew 124 of the 2,690 flights on BWI to ORD, about 5% of it. Its 85.4% on time is 11 points better than the route as a whole, which runs 74.9%. Ranked by on-time rate it is first of eight carriers on the route, where the range runs from Southwest at 85.4% to American at 38.5%. Five of those carriers flew fewer than 365 flights here, so treat their positions as rough.
The two carriers here are closely matched: half a point 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 |
|---|---|---|---|---|---|
| Southwest Airlines (this page)thin 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 | 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+ |
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
When Southwest runs best on this route
Departure time matters more here than the choice of carrier. The gap between the best and worst window is 10 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–8am—
- 8am–11am70 flights89.9%
- 11am–2pm54 flights79.6%
- 2pm–5pm—
- 5pm–8pm—
- 8pm–5am—
Scale runs 70% to 95%. Rows with fewer than 30 flights show a dash.
The weak window here is the middle of the day, not the evening: 11am–2pm runs 79.6% on time against 89.9% for 8am–11am. That shape usually means a departure bank rather than an accumulating delay, so the recovery later in the afternoon is real rather than noise. The 8am–11am window is the busiest, with 70 flights scheduled in it.
Across the year
Southwest on BWI to ORD through the year
- Jul–Sep 202592 flights83.5%
- Oct–Dec 202532 flights90.6%
Scale runs 75% to 95%. Rows with fewer than 30 flights show a dash.
Monthly volumes are too low here to break the year into twelve reliable readings. What the twelve-month total says is 85.4% on time across 124 flights.
Split by quarter, Southwest on BWI to ORD logged 92 flights in Jul–Sep 2025 and 32 flights in Oct–Dec 2025. Fewer than three of those quarters carried the 30 completed flights this site needs before printing a rate, so the 85.4% annual figure is the one to use.
Delay causes
Why Southwest runs late on this route
One category carries most of the weight here. Carrier accounts for 61% of the 901 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.
- 61%Carrier
- 37%National Airspace System
- 2%Late-arriving aircraft
37% 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 332 minutes out of 901, against a national NAS share of 21%. The split is drawn from 901 reported delay minutes.
The largest share of delay minutes, 61%, falls under carrier control: crew scheduling, maintenance, fuelling, baggage. Unlike weather, that is a management outcome, and it is the category where the gap between two carriers on the same schedule is genuinely earned. It accounts for 553 of the 901 delay minutes reported here.
Cancellations are rare at 0.81%, below the national 1.81% and low enough to earn the plus on the grade. Roughly one flight in 100 is called off; the risk here is arriving late, not not arriving.
Connections and stage length
What a delay here costs
Badly late arrivals are rare here: only 3.3% land an hour or more behind schedule, against 8.1% nationally. Connections built on this flight are about as safe as US domestic connections get, though a cancelled flight still ignores every layover you give it.
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 63.1% on time across 124 flights, 22 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 22 points of difference.
One caution: this is a thin sample. 124 flights over twelve months is enough to clear this site's floor but not enough to pin the rate down tightly, and a single bad week moves it by more than a point. Treat the grade as a rough reading.
What to do with this
Booking Southwest on BWI to ORD
Put together: treat all of this as provisional. 124 flights over twelve months is enough to clear this site's floor and not enough to be confident to better than a couple of points. The 85.4% headline is the most reliable number on the page; the hour and month splits below it are built on a few dozen flights each. 123 completed flights over 12 months sit behind that.
Related
Where to go next
- BWI to ORD, every carrier
- Southwest on ORD to BWI, the return leg
- Republic Airways on BWI to ORD83.0%
- United Airlines on BWI to ORD75.1%
- Envoy Air on BWI to ORD74.7%
- Frontier Airlines on BWI to ORD64.3%
- Southwest 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
- Late aircraft, weather, or the airline: what actually causes US flight delays
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.