Carrier route record
WNBWI→LAS
Southwest Airlines · Baltimore to Las Vegas
- Flights
- 1,624
- Period
- September 2025 to August 2026
- Share of route
- 93%
- Carriers
- 2
Historical statistics for September 2025 to August 2026, not live status. For today’s flights, check with Southwest Airlines.
Southwest on BWI to LAS lands a B+, about a point better than the national rate of 77.3%. About one flight in five arrives 15 minutes late or worse, and those flights are late by about 55 minutes on average. That rests on 1,624 flights, with a median arrival 4 minutes early.
The US average over the same twelve months is 77.3%, 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
78.3%
Arrivals under 15 minutes late, of 1,601 completed flights
Avg delay
54 min
Across delayed arrivals only, not all flights
Cancelled
0.99%
National rate is 1.89%
Whole route
79.0%
Every carrier on BWI to LAS, 1,739 flights
These figures cover 1,624 flights between September 2025 and August 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.
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Carrier by carrier
Southwest against every carrier on BWI to LAS
Southwest flew 1,624 of the 1,739 flights on BWI to LAS, most of the route. Its 78.3% on time is about level with the route as a whole at 79.0%. Ranked by on-time rate it is last of two carriers on the route, where the range runs from Spirit at 88.7% to Southwest at 78.3%. 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 | 115 | 88.7% | 62 min | 0.00% | A+ |
| Southwest Airlines (this page) | 1,624 | 78.3% | 54 min | 0.99% | B+ |
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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 26 points, against half a point between the best and worst carrier.
- 5am–8am344 flights90.7%
- 8am–11am357 flights88.7%
- 11am–2pm153 flights76.3%
- 2pm–5pm298 flights71.3%
- 5pm–8pm342 flights66.5%
- 8pm–5am130 flights65.1%
Scale runs 55% to 95%.
Book the early departure. Flights leaving between 5am–8am arrive on time 90.7% of the time, against 65.1% for the overnight window. That is 26 points of difference for no extra money, and it comes from the same aircraft having had no earlier flight to fall behind on. The 8am–11am window is the busiest, with 357 flights scheduled in it.
Across the year
Southwest on BWI to LAS through the year
June is the worst month at 65.5% 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 83.1% on time and Friday the weakest at 74.5%, a spread of 9 points.
Arrival by arrival
How late Southwest on BWI to LAS runs when it is late
Southwest on BWI to LAS often beats the schedule: 440 of 1,601 completed flights, 27%, arrived 15 minutes or more early. The 348 late arrivals split 142 under half an hour, 107 between 30 and 60 minutes, and 99 an hour or more.
- 15+ min early440 flights27.5%
- Within 15 min813 flights50.8%
- 15–29 min late142 flights8.9%
- 30–59 min late107 flights6.7%
- 1–2 hours late66 flights4.1%
- 2+ hours late33 flights2.1%
Scale runs 0% to 100%.
Share of 1,601 completed flights by arrival against schedule.
A late pushback is often recovered here: of 523 departures that left 15 minutes late or more, 230 still arrived on time. 55 flights left on time and still arrived late.
The worst days
Worst days for Southwest on BWI to LAS
The latest arrival of the period was on 16 February 2026, 6 hours 19 minutes behind schedule; most of its delay minutes were filed as security. The five worst days are spread across February, October, July, August and June, with no single month standing out.
| Date | Arrived late by | Largest filed cause |
|---|---|---|
| 16 February 2026 | 6 hours 19 minutes | Security |
| 5 October 2025 | 5 hours 21 minutes | Carrier |
| 28 July 2026 | 5 hours 8 minutes | Late-arriving aircraft |
| 2 August 2026 | 4 hours 39 minutes | Late-arriving aircraft |
| 18 June 2026 | 4 hours 14 minutes | Carrier |
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.
- 38%Carrier
- 35%Late-arriving aircraft
- 21%National Airspace System
- 5%Extreme weather
- 2%Security
35% of delay minutes trace back to a late-arriving aircraft, meaning the plane was already behind before it got here. Across 19,000 reported delay minutes here, that single category outweighs weather by 7 to one. The split is drawn from 18,834 reported delay minutes.
The largest share of delay minutes, 38%, falls under carrier control: crew scheduling, maintenance, fuelling, baggage. It accounts for 7,117 of the 19,000 delay minutes reported here.
Cancellations sit at 0.99% against a national 1.89%, 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 8.3%, 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 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 78.6% on time across 1,630 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 1,624 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 June 65.5%, a swing of 22 points. If the dates move at all, move them out of June before you think about anything else. 1,601 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 LAS88.7%
- 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 7.05 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.