Carrier route record
WNBWI→LAX
Southwest Airlines · Baltimore to Los Angeles
- Flights
- 1,046
- Period
- September 2025 to August 2026
- Share of route
- 63%
- Carriers
- 3
Historical statistics for September 2025 to August 2026, not live status. For today’s flights, check with Southwest Airlines.
Southwest on BWI to LAX draws a C. About one flight in three arrives at least 15 minutes late, and the typical late arrival is about 50 minutes behind schedule. Build slack into anything you connect to. That rests on 1,046 flights, with a median arrival 4 minutes late.
The national on-time rate over the same period is 77.3%, so Southwest on BWI to LAX runs 11 points behind the country as a whole. Across a thousand flights that is about 110 extra late arrivals.
Key figures
On time
66.3%
Arrivals under 15 minutes late, of 1,029 completed flights
Avg delay
50 min
Across delayed arrivals only, not all flights
Cancelled
1.53%
National rate is 1.89%
Whole route
72.8%
Every carrier on BWI to LAX, 1,670 flights
These figures cover 1,046 flights between September 2025 and August 2026. Beyond the headline rate, 8.2% of arrivals land a full hour or more behind schedule, against 8.3% nationally.
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Carrier by carrier
Southwest against every carrier on BWI to LAX
Southwest flew 1,046 of the 1,670 flights on BWI to LAX, most of the route. Its 66.3% on time is 7 points worse than the route as a whole, which runs 72.8%. Ranked by on-time rate it is last of three carriers on the route, where the range runs from Spirit at 91.1% to Southwest at 66.3%. One 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 | 46 | 91.1% | 31 min | 2.17% | A |
| United Airlines | 578 | 83.2% | 77 min | 0.87% | B+ |
| Southwest Airlines (this page) | 1,046 | 66.3% | 50 min | 1.53% | C |
Timetable by Aviasales, a Travelpayouts partner. Booking through it may earn this site a commission at no cost to you; it changes no figure here.
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 33 points, against half a point between the best and worst carrier.
- 5am–8am210 flights82.6%
- 8am–11am140 flights85.5%
- 11am–2pm48 flights72.9%
- 2pm–5pm286 flights58.8%
- 5pm–8pm163 flights56.5%
- 8pm–5am199 flights52.4%
Scale runs 45% to 90%.
The 8pm–5am window is where this operation falls apart: 52.4% on time, against 85.5% for the 8am–11am 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 286 flights scheduled in it.
Across the year
Southwest on BWI to LAX through the year
June is the worst month at 38.9% on time, 41 points below November, the best at 80.0%. Summer afternoon convection and peak-season schedules land on the same weeks every year, so this is a pattern you can book around rather than a run of bad luck. July was the busiest month here, with 93 flights.
Across the week, Saturday is the strongest day at 75.5% on time and Sunday the weakest at 57.8%, a spread of 18 points.
Arrival by arrival
How late Southwest on BWI to LAX runs when it is late
The 347 late arrivals split 148 under half an hour, 115 between 30 and 60 minutes, and 84 an hour or more.
- 15+ min early180 flights17.5%
- Within 15 min502 flights48.8%
- 15–29 min late148 flights14.4%
- 30–59 min late115 flights11.2%
- 1–2 hours late58 flights5.6%
- 2+ hours late26 flights2.5%
Scale runs 0% to 100%.
Share of 1,029 completed flights by arrival against schedule.
A late pushback is often recovered here: of 411 departures that left 15 minutes late or more, 130 still arrived on time. In the other direction, 66 flights left on time yet arrived 15 minutes late or more, so that delay built up after pushback: in the air, in a holding pattern or on the ground at LAX.
The worst days
Worst days for Southwest on BWI to LAX
The latest arrival of the period was on 28 July 2026, 4 hours 29 minutes behind schedule; most of its delay minutes were filed as a late-arriving aircraft. The same cause led on four of the five worst days.
| Date | Arrived late by | Largest filed cause |
|---|---|---|
| 28 July 2026 | 4 hours 29 minutes | Late-arriving aircraft |
| 2 February 2026 | 4 hours 26 minutes | Late-arriving aircraft |
| 4 July 2026 | 4 hours 23 minutes | National Airspace System |
| 20 May 2026 | 4 hours 14 minutes | Late-arriving aircraft |
| 14 June 2026 | 3 hours 50 minutes | Late-arriving aircraft |
Delay causes
Why Southwest runs late on this route
Carriers report a reason for every delay minute they cause, in five DOT categories. The split below is by minutes, not by number of flights, so a handful of very long weather delays weighs as much as many short ones. It covers 17,000 reported delay minutes.
- 39%Late-arriving aircraft
- 36%Carrier
- 20%National Airspace System
- 4%Extreme weather
- 1%Security
39% of delay minutes trace back to a late-arriving aircraft, meaning the plane was already behind before it got here. Across 17,000 reported delay minutes here, that single category outweighs weather by 9 to one. The split is drawn from 17,395 reported delay minutes.
The largest share of delay minutes, 36%, falls under carrier control: crew scheduling, maintenance, fuelling, baggage. It accounts for 6,215 of the 17,000 delay minutes reported here.
Cancellations sit at 1.53% against a national 1.89%, which is ordinary. Diversions add another 0.10%.
Connections and stage length
What a delay here costs
8.2% of arrivals land an hour or more late, close to the national 8.3%, so a 60 to 75 minute layover is reasonable here while anything under 45 minutes is a bet. Most delays on this route last about 50 minutes, which a normal layover absorbs.
At 2,329 miles this is transcontinental flying, and long routes get a quiet structural advantage. Scheduled block time on a flight this length carries more padding in absolute minutes, so a twenty-minute late departure often still becomes an on-time arrival. Read the on-time rate here as slightly flattering next to a short-haul route with the same operational quality.
The return leg is a different operation and performs like one: it runs 76.2% on time across 1,022 flights, 10 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 10 points of difference.
One caution: this is a thin sample. 1,046 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 LAX
Put together: treat all of this as provisional. 1,046 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 66.3% headline is the most reliable number on the page; the hour and month splits below it are built on a few dozen flights each. 1,029 completed flights over 12 months sit behind that.
Related
Where to go next
- BWI to LAX, every carrier
- Southwest on LAX to BWI, the return leg
- United Airlines on BWI to LAX83.2%
- Southwest Airlines network-wide record
- Baltimore/Washington International Thurgood Marshall (BWI) delay statistics
- Los Angeles International (LAX) delay statistics
- Why the first flight of the morning is statistically safest
- The best time of day to fly, according to 7.05 million flight records
Source: US DOT Bureau of Transportation Statistics, on-time performance data, September 2025 to August 2026. Last updated ; recomputed monthly. How this data is collected.