Carrier route record
WNBWI→LAS
Southwest Airlines · Baltimore to Las Vegas
- Flights
- 1,630
- Period
- July 2025 to June 2026
- Share of route
- 90%
- Carriers
- 2
Historical statistics for July 2025 to June 2026, not live status. For today’s flights, check with Southwest Airlines.
Southwest on BWI to LAS lands a B, level with the national rate of 77.6%. Roughly one flight in five arrives 15 minutes late or worse, and those flights are late by about 55 minutes on average. That is a workable record, not a spotless one. That rests on 1,630 flights, with a median arrival 4 minutes early.
The US average over the same twelve months is 77.6%, so there is little to separate Southwest on BWI to LAS from the country as a whole. The variation that matters here is internal: which carrier, and what time of day.
Key figures
On time
78.1%
Arrivals under 15 minutes late, of 1,605 completed flights
Avg delay
55 min
Across delayed arrivals only, not all flights
Cancelled
1.10%
National rate is 1.81%
Whole route
78.9%
Every carrier on BWI to LAS, 1,811 flights
These figures cover 1,630 flights between July 2025 and June 2026. The median arrival is 4 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 BWI to LAS
Southwest flew 1,630 of the 1,811 flights on BWI to LAS, most of the route. Its 78.1% on time is about level with the route as a whole at 78.9%. Ranked by on-time rate it is last of two carriers on the route, where the range runs from Spirit at 86.1% to Southwest at 78.1%. 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 | 181 | 86.1% | 68 min | 0.55% | A+ |
| Southwest Airlines (this page) | 1,630 | 78.1% | 55 min | 1.10% | 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 28 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–8am348 flights90.2%
- 8am–11am334 flights89.1%
- 11am–2pm170 flights76.3%
- 2pm–5pm302 flights69.9%
- 5pm–8pm338 flights69.0%
- 8pm–5am138 flights62.6%
Scale runs 55% to 95%. Rows with fewer than 30 flights show a dash.
The 8pm–5am window is where this operation falls apart: 62.6% on time, against 90.2% for the 5am–8am 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 5am–8am window is the busiest, with 348 flights scheduled in it.
Across the year
Southwest on BWI to LAS through the year
July is the worst month at 64.9% on time, 22 points below November, the best at 87.1%. 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. December was the busiest month here, with 150 flights.
Across the week, Tuesday is the strongest day at 81.9% on time and Thursday the weakest at 72.8%. 9 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 19,000 reported delay minutes.
- 35%Carrier
- 33%Late-arriving aircraft
- 22%National Airspace System
- 8%Extreme weather
- 2%Security
The largest share of delay minutes, 35%, 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 6,738 of the 19,000 delay minutes reported here. The split is drawn from 19,285 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 90.2% on time here.
Cancellations sit at 1.10% against a national 1.81%, which is ordinary. Diversions add another 0.43%.
Connections and stage length
What a delay here costs
6.2% 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 55 minutes, which a normal layover absorbs.
At 2,106 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 runs 78.5% on time across 1,625 flights, within half a point of this direction. The two legs are scored separately because they usually differ; on this city pair they happen not to.
The sample behind these figures is 1,630 flights, enough that the headline rate is stable to within roughly a point. The hour-block and month splits divide that further, so read the thinner bars with more caution than the headline.
What to do with this
Booking Southwest on BWI to LAS
Put together: the calendar is the biggest lever here, not the carrier or the hour. November runs 87.1% on time and July 64.9%, a swing of 22 points. If the dates move at all, move them out of July before you think about anything else. 1,605 completed flights over 12 months sit behind that.
Related
Where to go next
- BWI to LAS, every carrier
- Southwest on LAS to BWI, the return leg
- Spirit Airlines on BWI to LAS86.1%
- Southwest Airlines network-wide record
- Baltimore/Washington International Thurgood Marshall (BWI) delay statistics
- Harry Reid International (LAS) 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.