Carrier route record
F9LAX→SFO
Frontier Airlines · Los Angeles to San Francisco
- Flights
- 391
- Period
- July 2025 to June 2026
- Share of route
- 4%
- Carriers
- 7
Historical statistics for July 2025 to June 2026, not live status. For today’s flights, check with Frontier Airlines.
Frontier on LAX to SFO earns an F, which is as low as this site's scale goes for a reason. Only 53.3% of flights arrive inside the 15-minute window, 24 points worse than the national rate of 77.6%. Late arrivals average a little over an hour. Treat any tight connection here as a coin flip. That rests on 391 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
53.3%
Arrivals under 15 minutes late, of 383 completed flights
Avg delay
72 min
Across delayed arrivals only, not all flights
Cancelled
2.05%
National rate is 1.81%
Whole route
64.8%
Every carrier on LAX to SFO, 11,013 flights
These figures cover 391 flights between July 2025 and June 2026. Beyond the headline rate, 19.6% 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 LAX to SFO
Frontier flew 391 of the 11,013 flights on LAX to SFO, about 4% of it. Its 53.3% on time is 12 points worse than the route as a whole, which runs 64.8%. Ranked by on-time rate it is number six 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 | 1,370 | 57.1% | 61 min | 0.36% | D+ |
| Frontier Airlines (this page) | 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 Frontier 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 391 flights.
- 5am–8am3 flights—
- 8am–11am72 flights57.7%
- 11am–2pm8 flights—
- 2pm–5pm23 flights—
- 5pm–8pm224 flights50.0%
- 8pm–5am61 flights48.3%
Scale runs 40% to 65%. Rows with fewer than 30 flights show a dash.
The 8pm–5am window is where this operation falls apart: 48.3% on time, against 57.7% for the 8am–11am 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 5pm–8pm window is the busiest, with 224 flights scheduled in it.
Across the year
Frontier on LAX to SFO through the year
- Jul–Sep 202589 flights57.3%
- Oct–Dec 2025126 flights55.6%
- Jan–Mar 202685 flights71.2%
- Apr–Jun 202691 flights30.0%
Scale runs 20% to 75%. Rows with fewer than 30 flights show a dash.
Monthly volumes are too low here to break the year into twelve reliable readings. What the twelve-month total says is 53.3% on time across 391 flights.
Frontier on LAX to SFO did not run the same all year. Its best quarter was Jan–Mar 2026 at 71.2% on time and its weakest Apr–Jun 2026 at 30.0%, a swing of 41 points on roughly 98 flights a quarter. The twelve-month rate averages over that, so if you are flying in a weak quarter the quarter's own figure is the better guide.
Across the week, Wednesday is the strongest day at 63.2% on time and Sunday the weakest at 40.9%. 22 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. National Airspace System accounts for 49% of the 13,000 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.
- 49%National Airspace System
- 26%Carrier
- 25%Late-arriving aircraft
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 6,334 minutes out of 13,000, against a national NAS share of 21%. The split is drawn from 12,825 reported delay minutes.
Cancellations sit at 2.05% 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. 19.6% 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 68.6% on time across 391 flights, 15 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 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 LAX to SFO
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 53.3% headline is the most reliable number on the page; the hour and month splits below it are built on a few dozen flights each. 383 completed flights over 12 months sit behind that.
Related
Where to go next
- LAX to SFO, every carrier
- Frontier 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%
- Southwest Airlines on LAX to SFO57.1%
- Alaska Airlines on LAX to SFO52.3%
- Frontier 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
- The best time of day to fly, according to 7.04 million flight records
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.