Carrier route record

WNLAX→BWI

Southwest Airlines · Los Angeles to Baltimore

Flights: 1,038
Period: July 2025 to June 2026
Share of route: 60%
Carriers: 3

Historical statistics for July 2025 to June 2026, not live status. For today’s flights, check with Southwest Airlines.

Southwest on LAX to BWI lands a B+, 2 points better than the national rate of 77.6%. About one flight in five arrives 15 minutes late or worse, and those flights are late by about 40 minutes on average. That is a workable record, not a spotless one. That rests on 1,038 flights, with a median arrival 3 minutes early.

The US average over the same twelve months is 77.6%, so there is little to separate Southwest on LAX to BWI from the country as a whole. The variation that matters here is internal: which carrier, and what time of day.

On time

79.8%

Arrivals under 15 minutes late, of 1,027 completed flights

Avg delay

40 min

Across delayed arrivals only, not all flights

Cancelled

0.77%

National rate is 1.81%

Whole route

83.2%

Every carrier on LAX to BWI, 1,722 flights

These figures cover 1,038 flights between July 2025 and June 2026. The median arrival is 3 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 LAX to BWI

Southwest flew 1,038 of the 1,722 flights on LAX to BWI, most of the route. Its 79.8% on time is 3 points worse than the route as a whole, which runs 83.2%. Ranked by on-time rate it is number two of three carriers on the route, where the range runs from United at 90.7% to Spirit at 75.0%. 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.

On-time performance by carrier on LAX to BWI
Airline	Flights	On time	Avg delay	Cancelled	Grade
United Airlines	575	90.7%	65 min	0.35%	A+
Southwest Airlines (this page)	1,038	79.8%	40 min	0.77%	B+
Spirit Airlinesthin sample	109	75.0%	70 min	0.92%	B+

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 34 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–8am346 flights92.4%
8am–11am120 flights71.8%
11am–2pm181 flights58.2%
2pm–5pm26 flights—
5pm–8pm—
8pm–5am365 flights83.2%

Scale runs 50% to 100%. 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 58.2% on time against 92.4% for 5am–8am. 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 8pm–5am window is the busiest, with 365 flights scheduled in it.

Across the year

Southwest on LAX to BWI through the year

Darker means more delays. Figures are on-time percentages.January best, March worst

Delays peak in March, when the on-time rate falls to 64.0%. January is the strongest month at 93.1%. Moving a flexible trip across that boundary buys 29 points. July was the busiest month here, with 93 flights.

Across the week, Saturday is the strongest day at 83.9% on time and Sunday the weakest at 73.2%. 11 points is a smaller lever than departure hour, but it is free.

Delay causes

Why Southwest runs late on this route

One category carries most of the weight here. Late-arriving aircraft accounts for 44% of the 8,234 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.

Late-arriving aircraft
44%
Carrier
33%
National Airspace System
23%
Extreme weather
0%

44% 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 8,234 reported delay minutes here, that single category outweighs weather by 44 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 8,234 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 92.4% on time here.

Cancellations are rare at 0.77%, 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 3.1% 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.

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 67.2% on time across 1,045 flights, 13 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 13 points of difference.

One caution: this is a thin sample. 1,038 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 LAX to BWI

Put together: treat all of this as provisional. 1,038 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 79.8% headline is the most reliable number on the page; the hour and month splits below it are built on a few dozen flights each. 1,027 completed flights over 12 months sit behind that.

Where to go next

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.

Key figures