Carrier route record
WNORD→BWI
Southwest Airlines · Chicago to Baltimore
- 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 ORD to BWI draws a D. Roughly one flight in three arrives at least 15 minutes late, and the typical late arrival is an hour and a half behind schedule. Build slack into anything you connect to. That rests on 124 flights. The strongest carrier on the route with a full sample, Envoy Air, flew 903 at 76.4% on time.
The national on-time rate over the same period is 77.6%, so Southwest on ORD to BWI runs 14 points behind the country as a whole. Across a thousand flights that is about 145 extra late arrivals.
Key figures
On time
63.1%
Arrivals under 15 minutes late, of 122 completed flights
Avg delay
84 min
Across delayed arrivals only, not all flights
Cancelled
1.61%
National rate is 1.81%
Whole route
71.9%
Every carrier on ORD to BWI, 2,696 flights
These figures cover 124 flights between July 2025 and June 2026. Beyond the headline rate, 12.3% 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
Southwest against every carrier on ORD to BWI
Southwest flew 124 of the 2,696 flights on ORD to BWI, about 5% of it. Its 63.1% on time is 9 points worse than the route as a whole, which runs 71.9%. Ranked by on-time rate it is number seven of eight carriers on the route, where the range runs from Spirit at 77.8% to American at 57.7%. Five of those carriers flew fewer than 365 flights here, so treat their positions as rough.
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 Airlines (this page)thin 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
When Southwest runs best on this route
Departure time is the single lever a traveller controls, and it moves the odds more than most people expect. Each bar below is the on-time rate for flights scheduled to leave inside that window, across 124 flights.
There are not enough flights in each departure window to split Southwest's ORD to BWI record by time of day without the percentages moving on noise. The headline rate of 63.1% is the reliable figure here.
Across the year
Southwest on ORD to BWI through the year
- Jul–Sep 202592 flights56.7%
- Oct–Dec 202532 flights81.2%
Scale runs 50% to 85%. 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 63.1% on time across 124 flights.
Split by quarter, Southwest on ORD to BWI 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 63.1% 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 46% of the 3,778 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%Carrier
- 26%Late-arriving aircraft
- 24%National Airspace System
- 4%Extreme weather
The largest share of delay minutes, 46%, 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 1,725 of the 3,778 delay minutes reported here. The split is drawn from 3,778 reported delay minutes.
Cancellations sit at 1.61% against a national 1.81%, which is ordinary. Diversions add another 0.00%.
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. 12.3% 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 85.4% on time across 124 flights, 22 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 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 ORD to BWI
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 63.1% headline is the most reliable number on the page; the hour and month splits below it are built on a few dozen flights each. 122 completed flights over 12 months sit behind that.
Related
Where to go next
- ORD to BWI, every carrier
- Southwest on BWI to ORD, the return leg
- Envoy Air on ORD to BWI76.4%
- United Airlines on ORD to BWI71.1%
- Republic Airways on ORD to BWI70.5%
- Frontier Airlines on ORD to BWI65.3%
- Southwest Airlines network-wide record
- Chicago O'Hare International (ORD) delay statistics
- Baltimore/Washington International Thurgood Marshall (BWI) delay statistics
- How often a connection fails at the major US hubs
- 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.