Carrier route record
WNLAS→DCA
Southwest Airlines · Las Vegas to Washington
- Flights
- 364
- Period
- September 2025 to August 2026
- Share of route
- 50%
- Carriers
- 2
Historical statistics for September 2025 to August 2026, not live status. For today’s flights, check with Southwest Airlines.
Southwest on LAS to DCA sits in the middle of the pack with a C+. About seven flights in ten arrive on time by the DOT's definition, 8 points worse than the national rate of 77.3%. The late ones land about 40 minutes behind schedule. That rests on 364 flights, with a median arrival 2 minutes late.
The national on-time rate over the same period is 77.3%, so Southwest on LAS to DCA runs 8 points behind the country as a whole. Across a thousand flights that is about 76 extra late arrivals.
Key figures
On time
69.7%
Arrivals under 15 minutes late, of 360 completed flights
Avg delay
40 min
Across delayed arrivals only, not all flights
Cancelled
0.55%
National rate is 1.89%
Whole route
74.3%
Every carrier on LAS to DCA, 728 flights
These figures cover 364 flights between September 2025 and August 2026. On-time means an arrival less than 15 minutes after the scheduled gate time, the same threshold the Department of Transportation uses in its own reports. Cancelled and diverted flights are excluded from the on-time rate and counted separately, which is why the cancellation column matters on its own.
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Carrier by carrier
Southwest against every carrier on LAS to DCA
Southwest flew 364 of the 728 flights on LAS to DCA, most of the route. Its 69.7% on time is 5 points worse than the route as a whole, which runs 74.3%. Ranked by on-time rate it is last of two carriers on the route, where the range runs from American at 78.9% to Southwest at 69.7%. 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 |
|---|---|---|---|---|---|
| American Airlinesthin sample | 364 | 78.9% | 79 min | 1.37% | B |
| Southwest Airlines (this page)thin sample | 364 | 69.7% | 40 min | 0.55% | C+ |
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Departure window
When Southwest runs best on this route
Departure time is the single lever a traveller controls, and it moves the odds more than most people expect. Each bar below is the on-time rate for flights scheduled to leave inside that window, across 364 flights.
- 5am–8am3 flights—
- 8am–11am331 flights69.1%
- 11am–2pm30 flights76.7%
- 2pm–5pm—
- 5pm–8pm—
- 8pm–5am—
Scale runs 60% to 80%. Rows with fewer than 30 flights show a dash.
The best window here is not the first bank but the 11am–2pm slot at 76.7% on time, ahead of 8am–11am at 69.1%. Where the curve peaks mid-day rather than at dawn, the constraint is usually congestion at one end rather than the aircraft's own rotation. The 8am–11am window is the busiest, with 331 flights scheduled in it.
Across the year
Southwest on LAS to DCA through the year
July is the worst month at 46.7% on time, 40 points below January, the best at 86.7%. 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. January was the busiest month here, with 31 flights.
Across the week, Saturday is the strongest day at 82.4% on time and Monday the weakest at 59.6%, a spread of 23 points.
Arrival by arrival
How late Southwest on LAS to DCA runs when it is late
The 109 late arrivals split 43 under half an hour, 45 between 30 and 60 minutes, and 21 an hour or more.
- 15+ min early75 flights20.8%
- Within 15 min176 flights48.9%
- 15–29 min late43 flights11.9%
- 30–59 min late45 flights12.5%
- 1–2 hours late20 flights5.6%
- 2+ hours late1 flights0.3%
Scale runs 0% to 100%.
Share of 360 completed flights by arrival against schedule.
A late pushback is often recovered here: of 115 departures that left 15 minutes late or more, 37 still arrived on time. In the other direction, 31 flights left on time yet arrived 15 minutes late or more, so that delay built up after pushback: in the air, in a holding pattern or on the ground at DCA.
The worst days
Worst days for Southwest on LAS to DCA
The latest arrival of the period was on 6 November 2025, 2 hours 23 minutes behind schedule; most of its delay minutes were filed as carrier-caused (crew, maintenance, fuelling, baggage). The five worst days are spread across November, March, February, September and July, with no single month standing out.
| Date | Arrived late by | Largest filed cause |
|---|---|---|
| 6 November 2025 | 2 hours 23 minutes | Carrier |
| 23 March 2026 | 1 hour 46 minutes | Late-arriving aircraft |
| 21 February 2026 | 1 hour 39 minutes | Late-arriving aircraft |
| 17 September 2025 | 1 hour 33 minutes | National Airspace System |
| 9 July 2026 | 1 hour 32 minutes | National Airspace System |
Delay causes
Why Southwest runs late on this route
National Airspace System accounts for 42% of the 4,401 delay minutes carriers reported here, and the remaining four split what is left.
- 42%National Airspace System
- 36%Carrier
- 17%Late-arriving aircraft
- 4%Extreme weather
42% of delay minutes are charged to the National Airspace System: air traffic volume, runway configuration, ground stops. No carrier can price its way out of that, which is why airport choice moves the number here more than carrier choice does. That is 1,861 minutes out of 4,401, against a national NAS share of 21%. The split is drawn from 4,401 reported delay minutes.
The largest share of delay minutes, 36%, falls under carrier control: crew scheduling, maintenance, fuelling, baggage. It accounts for 1,593 of the 4,401 delay minutes reported here.
Cancellations are rare at 0.55%, below the national 1.89% 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
5.8% 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 40 minutes, which a normal layover absorbs.
At 2,089 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 49.4% on time across 365 flights, 20 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 20 points of difference.
One caution: this is a thin sample. 364 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 LAS to DCA
Put together: treat all of this as provisional. 364 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 69.7% headline is the most reliable number on the page; the hour and month splits below it are built on a few dozen flights each. 360 completed flights over 12 months sit behind that.
Related
Where to go next
- LAS to DCA, every carrier
- Southwest on DCA to LAS, the return leg
- American Airlines on LAS to DCA78.9%
- Southwest Airlines network-wide record
- Harry Reid International (LAS) delay statistics
- Ronald Reagan Washington National (DCA) delay statistics
- Worst months to fly in the US, ranked by the data
- The best day of the week to fly, and why it is the second lever
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.