Carrier route record
F9SFO→LAX
Frontier Airlines · San Francisco to Los Angeles
- Flights
- 391
- Period
- July 2025 to June 2026
- Share of route
- 4%
- Carriers
- 8
Historical statistics for July 2025 to June 2026, not live status. For today’s flights, check with Frontier Airlines.
Frontier on SFO to LAX sits in the middle of the pack with a C. About seven flights in ten arrive on time by the DOT's definition, 9 points worse than the national rate of 77.6%. The late ones land an hour and a half behind schedule. That rests on 391 flights. The strongest carrier on the route with a full sample, United Airlines, flew 3,263 at 78.4% on time.
United Airlines is the most reliable of the five carriers covered here at 78.4% on time across 3,263 flights.
Key figures
On time
68.6%
Arrivals under 15 minutes late, of 385 completed flights
Avg delay
84 min
Across delayed arrivals only, not all flights
Cancelled
1.53%
National rate is 1.81%
Whole route
73.9%
Every carrier on SFO to LAX, 11,015 flights
These figures cover 391 flights between July 2025 and June 2026. Beyond the headline rate, 12.7% 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
Frontier against every carrier on SFO to LAX
Frontier flew 391 of the 11,015 flights on SFO to LAX, about 4% of it. Its 68.6% on time is 5 points worse than the route as a whole, which runs 73.9%. Ranked by on-time rate it is number six of eight carriers on the route, where the range runs from United at 78.4% to Envoy at 0.0%. Two of those carriers flew fewer than 365 flights here, so treat their positions as rough.
The choice of carrier is not cosmetic here. United Airlines arrives on time 78.4% of the time; Southwest Airlines manages 61.8%. Sample sizes sit next to every figure, because a two-point gap across 1,369 flights means less than a ten-point one.
| Airline | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| United Airlines | 3,263 | 78.4% | 49 min | 0.28% | B+ |
| American Airlinesthin sample | 345 | 76.7% | 108 min | 0.29% | B+ |
| SkyWest Airlines | 2,588 | 76.6% | 60 min | 1.04% | B |
| Delta Air Lines | 2,373 | 73.6% | 65 min | 1.56% | C |
| Alaska Airlines | 685 | 69.7% | 47 min | 0.73% | C+ |
| Frontier Airlines (this page) | 391 | 68.6% | 84 min | 1.53% | C |
| Southwest Airlines | 1,369 | 61.8% | 60 min | 0.58% | D+ |
| Envoy Airthin sample | 1 | 0.0% | 35 min | 0.00% | F+ |
The spread between United and Southwest is 17 points, wide enough that it should decide the booking. On a hundred trips that is 17 more arrivals inside the on-time window.
Departure window
When Frontier runs best on this route
Departure time matters more here than the choice of carrier. The gap between the best and worst window is 27 points, against 17 points between the best and worst carrier. Each bar is the on-time rate for flights scheduled inside that window.
- 5am–8am5 flights—
- 8am–11am34 flights84.8%
- 11am–2pm103 flights58.3%
- 2pm–5pm52 flights73.1%
- 5pm–8pm88 flights73.6%
- 8pm–5am109 flights65.7%
Scale runs 50% to 90%. Rows with fewer than 30 flights show a dash.
The weak window here is the middle of the day, not the evening: 11am–2pm runs 58.3% on time against 84.8% for 8am–11am. That shape usually means a departure bank rather than an accumulating delay, so the recovery later in the afternoon is real rather than noise. The 8pm–5am window is the busiest, with 109 flights scheduled in it.
Across the year
Frontier on SFO to LAX through the year
April is the best month on the calendar at 83.3% on time. Shoulder season thins the schedule and takes the summer weather with it, and the operation gets its margin back. October was the busiest month here, with 48 flights.
Across the week, Tuesday is the strongest day at 89.5% on time and Thursday the weakest at 59.0%. 31 points is a smaller lever than departure hour, but it is free.
Delay causes
Why Frontier runs late on this route
One category carries most of the weight here. Late-arriving aircraft accounts for 60% of the 10,000 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.
- 60%Late-arriving aircraft
- 30%Carrier
- 10%National Airspace System
60% 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 10,000 reported delay minutes here, that single category outweighs weather by 60 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 10,211 reported delay minutes.
The practical consequence: the 8am–11am departure is the one that starts clean. Its aircraft has no earlier leg to be late from, which is exactly why that window shows 84.8% on time here.
Cancellations sit at 1.53% against a national 1.81%, which is ordinary. Diversions add another 0.00%.
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. 12.7% 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 8am–11am window matters as much as it does.
The return leg is a different operation and performs like one: it runs 53.3% on time across 391 flights, 15 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 15 points of difference.
One caution: this is a thin sample. 391 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 Frontier on SFO to LAX
Put together: treat all of this as provisional. 391 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 68.6% headline is the most reliable number on the page; the hour and month splits below it are built on a few dozen flights each. 385 completed flights over 12 months sit behind that.
Related
Where to go next
- SFO to LAX, every carrier
- Frontier on LAX to SFO, the return leg
- United Airlines on SFO to LAX78.4%
- American Airlines on SFO to LAX76.7%
- SkyWest Airlines on SFO to LAX76.6%
- Delta Air Lines on SFO to LAX73.6%
- Alaska Airlines on SFO to LAX69.7%
- Southwest Airlines on SFO to LAX61.8%
- Frontier Airlines network-wide record
- San Francisco International (SFO) delay statistics
- Los Angeles International (LAX) delay statistics
- Why the first flight of the morning is statistically safest
- Same route, different airline: where the carrier you pick matters most
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.