Carrier route record
WNLAX→SFO
Southwest Airlines · Los Angeles to San Francisco
- Flights
- 1,473
- Period
- September 2025 to August 2026
- Share of route
- 13%
- Carriers
- 7
Historical statistics for September 2025 to August 2026, not live status. For today’s flights, check with Southwest Airlines.
Southwest on LAX to SFO earns an F+, which is as low as this site's scale goes for a reason. Only 50.7% of flights arrive inside the 15-minute window, 27 points worse than the national rate of 77.3%. Late arrivals average about an hour. Treat any tight connection here as a coin flip. That rests on 1,473 flights. The strongest carrier on the route with a full sample, SkyWest Airlines, flew 2,515 at 66.6% on time.
SkyWest Airlines is the most reliable of the five carriers covered here at 66.6% on time across 2,515 flights.
Key figures
On time
50.7%
Arrivals under 15 minutes late, of 1,468 completed flights
Avg delay
62 min
Across delayed arrivals only, not all flights
Cancelled
0.34%
National rate is 1.89%
Whole route
60.1%
Every carrier on LAX to SFO, 11,437 flights
These figures cover 1,473 flights between September 2025 and August 2026. Beyond the headline rate, 19.9% of arrivals land a full hour or more behind schedule, against 8.3% nationally.
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Carrier by carrier
Southwest against every carrier on LAX to SFO
Southwest flew 1,473 of the 11,437 flights on LAX to SFO, about 13% of it. Its 50.7% on time is 9 points worse than the route as a whole, which runs 60.1%. Ranked by on-time rate it is number six of seven carriers on the route, where the range runs from SkyWest at 66.6% to Frontier at 47.7%. One of those carriers flew fewer than 365 flights here, so treat their positions as rough.
The choice of carrier is not cosmetic here. SkyWest Airlines arrives on time 66.6% of the time; Frontier Airlines manages 47.7%. Sample sizes sit next to every figure, because a two-point gap across 395 flights means less than a ten-point one.
| Airline | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| SkyWest Airlines | 2,515 | 66.6% | 58 min | 1.19% | C |
| American Airlinesthin sample | 302 | 63.9% | 76 min | 0.00% | D+ |
| United Airlines | 3,330 | 62.9% | 56 min | 0.12% | D+ |
| Delta Air Lines | 2,373 | 60.9% | 53 min | 1.56% | D |
| Alaska Airlines | 1,049 | 50.9% | 54 min | 0.67% | F+ |
| Southwest Airlines (this page) | 1,473 | 50.7% | 62 min | 0.34% | F+ |
| Frontier Airlines | 395 | 47.7% | 66 min | 2.28% | F |
The spread between SkyWest and Frontier is 19 points, wide enough that it should decide the booking. On a hundred trips that is 19 more arrivals inside the on-time window.
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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 74 points, against 19 points between the best and worst carrier.
- 5am–8am315 flights93.9%
- 8am–11am218 flights41.5%
- 11am–2pm291 flights48.6%
- 2pm–5pm176 flights36.6%
- 5pm–8pm262 flights43.1%
- 8pm–5am211 flights20.4%
Scale runs 10% to 100%.
The 8pm–5am window is where this operation falls apart: 20.4% on time, against 93.9% 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 315 flights scheduled in it.
Across the year
Southwest on LAX to SFO through the year
June is the worst month at 25.7% on time, 57 points below January, the best at 83.0%. 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. August was the busiest month here, with 167 flights.
Across the week, Saturday is the strongest day at 59.6% on time and Friday the weakest at 44.5%, a spread of 15 points.
Arrival by arrival
How late Southwest on LAX to SFO runs when it is late
The 723 late arrivals split 177 under half an hour, 254 between 30 and 60 minutes, and 292 an hour or more.
- 15+ min early209 flights14.2%
- Within 15 min536 flights36.5%
- 15–29 min late177 flights12.1%
- 30–59 min late254 flights17.3%
- 1–2 hours late218 flights14.9%
- 2+ hours late74 flights5.0%
Scale runs 0% to 100%.
Share of 1,468 completed flights by arrival against schedule.
94 of 714 late departures made up the time and arrived on time, 13% of them. In the other direction, 103 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 SFO.
The worst days
Worst days for Southwest on LAX to SFO
The latest arrival of the period was on 25 July 2026, 4 hours 36 minutes behind schedule; most of its delay minutes were filed as a late-arriving aircraft. The same cause led on four of the five worst days.
| Date | Arrived late by | Largest filed cause |
|---|---|---|
| 25 July 2026 | 4 hours 36 minutes | Late-arriving aircraft |
| 22 June 2026 | 4 hours 26 minutes | Late-arriving aircraft |
| 30 April 2026 | 4 hours 22 minutes | Late-arriving aircraft |
| 2 January 2026 | 4 hours 15 minutes | Carrier |
| 19 June 2026 | 4 hours 12 minutes | Late-arriving aircraft |
Delay causes
Why Southwest runs late on this route
National Airspace System accounts for 49% of the 45,000 delay minutes carriers reported here, and the remaining four split what is left.
- 49%National Airspace System
- 37%Late-arriving aircraft
- 14%Carrier
- 1%Extreme weather
37% of delay minutes trace back to a late-arriving aircraft, meaning the plane was already behind before it got here. Across 45,000 reported delay minutes here, that single category outweighs weather by 37 to one. The split is drawn from 44,620 reported delay minutes.
49% 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 22,000 minutes out of 45,000, against a national NAS share of 21%.
Cancellations are rare at 0.34%, 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
19.9% of arrivals land a full hour or more behind schedule, against 8.3% nationally. Ninety minutes is the honest minimum for a connection here, and two hours if the onward flight is on a separate ticket.
At 337 miles this is a short hop, and stage length matters more than it looks. A flight this short spends under two hours in the air, which leaves almost nothing to claw back a late pushback with. Delay here is decided on the ground, in the turn, which is why the 5am–8am window matters as much as it does.
The return leg is a different operation and performs like one: it runs 56.7% on time across 1,472 flights, 6 points above 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 6 points of difference.
The sample behind these figures is 1,473 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 LAX to SFO
Put together: the calendar is the biggest lever here, not the carrier or the hour. January runs 83.0% on time and June 25.7%, a swing of 57 points. If the dates move at all, move them out of June before you think about anything else. 1,468 completed flights over 12 months sit behind that.
Related
Where to go next
- LAX to SFO, every carrier
- Southwest on SFO to LAX, the return leg
- SkyWest Airlines on LAX to SFO66.6%
- American Airlines on LAX to SFO63.9%
- United Airlines on LAX to SFO62.9%
- Delta Air Lines on LAX to SFO60.9%
- Alaska Airlines on LAX to SFO50.9%
- Frontier Airlines on LAX to SFO47.7%
- Southwest Airlines network-wide record
- Los Angeles International (LAX) delay statistics
- San Francisco International (SFO) delay statistics
- Same route, different airline: where the carrier you pick matters most
- Why the first flight of the morning is statistically safest
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.