Carrier route record

WNLAX→BWI

Southwest Airlines · Los Angeles to Baltimore

Flights: 1,022
Period: September 2025 to August 2026
Share of route: 62%
Carriers: 3

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

Southwest on LAX to BWI lands a B, about a point worse than the national rate of 77.3%. About one flight in four arrives 15 minutes late or worse, and those flights are late by roughly 40 minutes on average. That rests on 1,022 flights, with a median arrival 2 minutes early.

The US average over the same twelve months is 77.3%, 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

76.2%

Arrivals under 15 minutes late, of 1,007 completed flights

Avg delay

38 min

Across delayed arrivals only, not all flights

Cancelled

1.08%

National rate is 1.89%

Whole route

80.8%

Every carrier on LAX to BWI, 1,647 flights

These figures cover 1,022 flights between September 2025 and August 2026. The median arrival is 2 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.

Fare search by Aviasales, a Travelpayouts partner. Booking through it may earn this site a commission at no cost to you; it changes no figure here.

Carrier by carrier

Southwest against every carrier on LAX to BWI

Southwest flew 1,022 of the 1,647 flights on LAX to BWI, most of the route. Its 76.2% on time is 5 points worse than the route as a whole, which runs 80.8%. Ranked by on-time rate it is last of three carriers on the route, where the range runs from United at 89.1% to Southwest at 76.2%. 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.

On-time performance by carrier on LAX to BWI
Airline	Flights	On time	Avg delay	Cancelled	Grade
United Airlines	577	89.1%	63 min	0.35%	A+
Spirit Airlinesthin sample	48	77.1%	39 min	0.00%	B+
Southwest Airlines (this page)	1,022	76.2%	38 min	1.08%	B

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 37 points, against half a point between the best and worst carrier.

5am–8am326 flights91.3%
8am–11am90 flights64.8%
11am–2pm215 flights54.6%
2pm–5pm26 flights—
5pm–8pm—
8pm–5am365 flights79.6%

Scale runs 45% 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 54.6% on time against 91.3% 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, July worst

July is the worst month at 57.0% on time, 36 points below January, the best at 93.1%. 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. May was the busiest month here, with 92 flights.

Across the week, Saturday is the strongest day at 80.9% on time and Sunday the weakest at 70.5%, a spread of 10 points.

Arrival by arrival

How late Southwest on LAX to BWI runs when it is late

Most of the lateness is short. 132 of the 240 late arrivals were under half an hour behind, and 32 reached an hour or more.

15+ min early195 flights19.4%
Within 15 min572 flights56.8%
15–29 min late132 flights13.1%
30–59 min late76 flights7.5%
1–2 hours late26 flights2.6%
2+ hours late6 flights0.6%

Scale runs 0% to 100%.

Share of 1,007 completed flights by arrival against schedule.

A late pushback is often recovered here: of 306 departures that left 15 minutes late or more, 115 still arrived on time. 49 flights left on time and still arrived late.

The worst days

Worst days for Southwest on LAX to BWI

The latest arrival of the period was on 2 July 2026, 4 hours 7 minutes behind schedule; most of its delay minutes were filed as carrier-caused (crew, maintenance, fuelling, baggage). On three of the five worst days the largest share was filed as a late-arriving aircraft.

The latest arrivals of Southwest on LAX to BWI in the period
Date	Arrived late by	Largest filed cause
2 July 2026	4 hours 7 minutes	Carrier
15 March 2026	2 hours 44 minutes	Late-arriving aircraft
23 December 2025	2 hours 39 minutes	Late-arriving aircraft
19 August 2026	2 hours 32 minutes	Carrier
20 April 2026	2 hours 20 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 9,171 reported delay minutes.

Late-arriving aircraft
41%
Carrier
38%
National Airspace System
20%
Extreme weather
0%

41% of delay minutes trace back to a late-arriving aircraft, meaning the plane was already behind before it got here. Across 9,171 reported delay minutes here, that single category outweighs weather by 41 to one. The split is drawn from 9,171 reported delay minutes.

The largest share of delay minutes, 38%, falls under carrier control: crew scheduling, maintenance, fuelling, baggage. It accounts for 3,495 of the 9,171 delay minutes reported here.

Cancellations sit at 1.08% against a national 1.89%, which is ordinary. Diversions add another 0.39%.

Connections and stage length

What a delay here costs

Badly late arrivals are rare here: only 3.2% land an hour or more behind schedule, against 8.3% 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 66.3% on time across 1,046 flights, 10 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 10 points of difference.

One caution: this is a thin sample. 1,022 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. 1,022 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 76.2% headline is the most reliable number on the page; the hour and month splits below it are built on a few dozen flights each. 1,007 completed flights over 12 months sit behind that.

Where to go next

Source: US DOT Bureau of Transportation Statistics, on-time performance data, September 2025 to August 2026. Last updated 22 October 2026; recomputed monthly. How this data is collected.

Key figures