Carrier route record
WNBWI→LAX
Southwest Airlines · Baltimore to Los Angeles
- Flights
- 1,045
- Period
- July 2025 to June 2026
- Share of route
- 61%
- Carriers
- 3
Historical statistics for July 2025 to June 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 1,045 flights, with a median arrival 2 minutes late.
The national on-time rate over the same period is 77.6%, so Southwest on BWI to LAX runs 10 points behind the country as a whole. Across a thousand flights that is about 104 extra late arrivals.
Key figures
On time
67.2%
Arrivals under 15 minutes late, of 1,031 completed flights
Avg delay
49 min
Across delayed arrivals only, not all flights
Cancelled
1.24%
National rate is 1.81%
Whole route
74.4%
Every carrier on BWI to LAX, 1,727 flights
These figures cover 1,045 flights between July 2025 and June 2026. Beyond the headline rate, 8.1% 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 BWI to LAX
Southwest flew 1,045 of the 1,727 flights on BWI to LAX, most of the route. Its 67.2% on time is 7 points worse than the route as a whole, which runs 74.4%. Ranked by on-time rate it is last of three carriers on the route, where the range runs from Spirit at 87.5% to Southwest at 67.2%. 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 | 106 | 87.5% | 104 min | 1.89% | A |
| United Airlines | 576 | 85.0% | 89 min | 1.22% | A |
| Southwest Airlines (this page) | 1,045 | 67.2% | 49 min | 1.24% | C |
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 38 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–8am222 flights83.9%
- 8am–11am124 flights89.3%
- 11am–2pm53 flights73.6%
- 2pm–5pm284 flights60.3%
- 5pm–8pm153 flights57.9%
- 8pm–5am209 flights51.0%
Scale runs 45% to 95%. Rows with fewer than 30 flights show a dash.
The 8pm–5am window is where this operation falls apart: 51.0% on time, against 89.3% 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 284 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 79.9% on time and Sunday the weakest at 59.6%. 20 points is a smaller lever than departure hour, but it is free.
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.
- 41%Late-arriving aircraft
- 36%Carrier
- 19%National Airspace System
- 3%Extreme weather
- 1%Security
41% 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 17,000 reported delay minutes here, that single category outweighs weather by 14 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 16,578 reported delay minutes.
The largest share of delay minutes, 36%, 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 6,023 of the 17,000 delay minutes reported here.
Cancellations sit at 1.24% against a national 1.81%, which is ordinary. Diversions add another 0.10%.
Connections and stage length
What a delay here costs
8.1% 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 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 79.8% on time across 1,038 flights, 13 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 13 points of difference.
One caution: this is a thin sample. 1,045 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. 1,045 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 67.2% headline is the most reliable number on the page; the hour and month splits below it are built on a few dozen flights each. 1,031 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
- Spirit Airlines on BWI to LAX87.5%
- United Airlines on BWI to LAX85.0%
- 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 7.04 million flight records
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.