Carrier route record
WNLAX→SFO
Southwest Airlines · Los Angeles to San Francisco
- Flights
- 1,370
- Period
- July 2025 to June 2026
- Share of route
- 12%
- Carriers
- 7
Historical statistics for July 2025 to June 2026, not live status. For today’s flights, check with Southwest Airlines.
Southwest on LAX to SFO earns a D+, which is as low as this site's scale goes for a reason. Only 57.1% of flights arrive inside the 15-minute window, 20 points worse than the national rate of 77.6%. Late arrivals average about an hour. Treat any tight connection here as a coin flip. That rests on 1,370 flights. The strongest carrier on the route with a full sample, SkyWest Airlines, flew 2,593 at 72.0% on time.
SkyWest Airlines is the most reliable of the five carriers covered here at 72.0% on time across 2,593 flights.
Key figures
On time
57.1%
Arrivals under 15 minutes late, of 1,365 completed flights
Avg delay
61 min
Across delayed arrivals only, not all flights
Cancelled
0.36%
National rate is 1.81%
Whole route
64.8%
Every carrier on LAX to SFO, 11,013 flights
These figures cover 1,370 flights between July 2025 and June 2026. Beyond the headline rate, 17.1% of arrivals land a full hour or more behind schedule. That is the number that wrecks a connection, and it is not visible in an on-time percentage alone.
Carrier by carrier
Southwest against every carrier on LAX to SFO
Southwest flew 1,370 of the 11,013 flights on LAX to SFO, about 12% of it. Its 57.1% on time is 8 points worse than the route as a whole, which runs 64.8%. Ranked by on-time rate it is number five of seven carriers on the route, where the range runs from SkyWest at 72.0% to Alaska at 52.3%. 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 72.0% of the time; Alaska Airlines manages 52.3%. Sample sizes sit next to every figure, because a two-point gap across 686 flights means less than a ten-point one.
| Airline | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| SkyWest Airlines | 2,593 | 72.0% | 59 min | 1.16% | C |
| United Airlines | 3,257 | 66.3% | 57 min | 0.25% | C+ |
| Delta Air Lines | 2,373 | 65.2% | 55 min | 1.52% | C |
| American Airlinesthin sample | 343 | 61.3% | 74 min | 0.29% | D+ |
| Southwest Airlines (this page) | 1,370 | 57.1% | 61 min | 0.36% | D+ |
| Frontier Airlines | 391 | 53.3% | 72 min | 2.05% | F |
| Alaska Airlines | 686 | 52.3% | 55 min | 0.44% | F+ |
The spread between SkyWest and Alaska is 20 points, wide enough that it should decide the booking. On a hundred trips that is 20 more arrivals inside the on-time window.
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 71 points, against 20 points between the best and worst carrier. Each bar is the on-time rate for flights scheduled inside that window.
- 5am–8am301 flights97.0%
- 8am–11am208 flights51.7%
- 11am–2pm259 flights58.9%
- 2pm–5pm161 flights42.5%
- 5pm–8pm236 flights46.6%
- 8pm–5am205 flights25.9%
Scale runs 15% to 100%. Rows with fewer than 30 flights show a dash.
The 8pm–5am window is where this operation falls apart: 25.9% on time, against 97.0% 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 301 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. June was the busiest month here, with 153 flights.
Across the week, Saturday is the strongest day at 66.3% on time and Friday the weakest at 50.5%. 16 points is a smaller lever than departure hour, but it is free.
Delay causes
Why Southwest runs late on this route
One category carries most of the weight here. National Airspace System accounts for 46% of the 36,000 delay minutes carriers reported, and the remaining four split what is left. The split is by minutes rather than by flights, so a few very long delays count for as much as many short ones.
- 46%National Airspace System
- 38%Late-arriving aircraft
- 15%Carrier
- 1%Extreme weather
38% of delay minutes trace back to a late-arriving aircraft, meaning the plane was already behind before it got here. That is a cascade, and cascades start small and grow through the day. Across 36,000 reported delay minutes here, that single category outweighs weather by 38 to one. It is the strongest argument for booking the first departure of the morning, when the aircraft has been sitting at the gate overnight with nothing to inherit. The split is drawn from 35,796 reported delay minutes.
46% 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 17,000 minutes out of 36,000, against a national NAS share of 21%.
Cancellations are rare at 0.36%, below the national 1.81% 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
For anyone connecting, the number to weigh is not the on-time rate but the tail behind it. 17.1% of arrivals land a full hour or more behind schedule, against 8.1% nationally. A 45-minute layover does not survive that, and no amount of walking quickly changes it. Ninety minutes is the honest minimum 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 61.8% on time across 1,369 flights, 5 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 5 points of difference.
The sample behind these figures is 1,370 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. 1,365 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 SFO72.0%
- United Airlines on LAX to SFO66.3%
- Delta Air Lines on LAX to SFO65.2%
- American Airlines on LAX to SFO61.3%
- Frontier Airlines on LAX to SFO53.3%
- Alaska Airlines on LAX to SFO52.3%
- 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, July 2025 to June 2026. Last updated 15 September 2026; recomputed monthly. How this data is collected.