Carrier route record
F9LAX→SFO
Frontier Airlines · Los Angeles to San Francisco
- Flights
- 395
- Period
- September 2025 to August 2026
- Share of route
- 3%
- Carriers
- 7
Historical statistics for September 2025 to August 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 47.7% of flights arrive inside the 15-minute window, 30 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 395 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
47.7%
Arrivals under 15 minutes late, of 386 completed flights
Avg delay
66 min
Across delayed arrivals only, not all flights
Cancelled
2.28%
National rate is 1.89%
Whole route
60.1%
Every carrier on LAX to SFO, 11,437 flights
These figures cover 395 flights between September 2025 and August 2026. Beyond the headline rate, 22.5% of arrivals land a full hour or more behind schedule, against 8.3% nationally.
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Carrier by carrier
Frontier against every carrier on LAX to SFO
Frontier flew 395 of the 11,437 flights on LAX to SFO, about 3% of it. Its 47.7% on time is 12 points worse than the route as a whole, which runs 60.1%. Ranked by on-time rate it is last 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; Southwest Airlines manages 50.7%. Sample sizes sit next to every figure, because a two-point gap across 1,473 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 | 1,473 | 50.7% | 62 min | 0.34% | F+ |
| Frontier Airlines (this page) | 395 | 47.7% | 66 min | 2.28% | F |
The spread between SkyWest and Southwest is 16 points, wide enough that it should decide the booking. On a hundred trips that is 16 more arrivals inside the on-time window.
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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 13 points, against 16 points between the best and worst carrier.
- 5am–8am3 flights—
- 8am–11am63 flights54.8%
- 11am–2pm8 flights—
- 2pm–5pm23 flights—
- 5pm–8pm232 flights41.9%
- 8pm–5am66 flights47.6%
Scale runs 35% to 60%. Rows with fewer than 30 flights show a dash.
The 5pm–8pm window is where this operation falls apart: 41.9% on time, against 54.8% 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 232 flights scheduled in it.
Across the year
Frontier on LAX to SFO through the year
July is the worst month at 10.0% on time, 51 points below December, the best at 61.3%. 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. October was the busiest month here, with 48 flights.
Across the week, Saturday is the strongest day at 62.0% on time and Sunday the weakest at 36.9%, a spread of 25 points.
Arrival by arrival
How late Frontier on LAX to SFO runs when it is late
The 202 late arrivals split 44 under half an hour, 71 between 30 and 60 minutes, and 87 an hour or more.
- 15+ min early67 flights17.4%
- Within 15 min117 flights30.3%
- 15–29 min late44 flights11.4%
- 30–59 min late71 flights18.4%
- 1–2 hours late60 flights15.5%
- 2+ hours late27 flights7.0%
Scale runs 0% to 100%.
Share of 386 completed flights by arrival against schedule.
Time lost at the gate mostly stays lost. Of 176 departures that left 15 minutes late or more, only 16 made it up before arrival. In the other direction, 42 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 Frontier on LAX to SFO
The latest arrival of the period was on 29 June 2026, 4 hours 41 minutes behind schedule; most of its delay minutes were filed as national airspace system delay. The five worst days are spread across June, September, February, October and December, with no single month standing out.
| Date | Arrived late by | Largest filed cause |
|---|---|---|
| 29 June 2026 | 4 hours 41 minutes | National Airspace System |
| 15 September 2025 | 3 hours 53 minutes | Carrier |
| 15 February 2026 | 3 hours 36 minutes | National Airspace System |
| 26 October 2025 | 3 hours 7 minutes | Late-arriving aircraft |
| 7 December 2025 | 3 hours 3 minutes | Carrier |
Delay causes
Why Frontier runs late on this route
National Airspace System accounts for 62% of the 13,000 delay minutes carriers reported here, and the remaining four split what is left.
- 62%National Airspace System
- 24%Late-arriving aircraft
- 13%Carrier
- 1%Extreme weather
62% 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 8,318 minutes out of 13,000, against a national NAS share of 21%. The split is drawn from 13,384 reported delay minutes.
Cancellations sit at 2.28% against a national 1.89%, which is ordinary. Diversions add another 0.00%.
Connections and stage length
What a delay here costs
22.5% 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 8am–11am window matters as much as it does.
The return leg is a different operation and performs like one: it runs 66.5% on time across 394 flights, 19 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 19 points of difference.
One caution: this is a thin sample. 395 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. 395 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 47.7% headline is the most reliable number on the page; the hour and month splits below it are built on a few dozen flights each. 386 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 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%
- Southwest Airlines on LAX to SFO50.7%
- 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 7.05 million flight records
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.