Carrier route record
F9SAN→SFO
Frontier Airlines · San Diego to San Francisco
- Flights
- 214
- Period
- September 2025 to August 2026
- Share of route
- 3%
- Carriers
- 5
Historical statistics for September 2025 to August 2026, not live status. For today’s flights, check with Frontier Airlines.
Frontier on SAN to SFO earns an F−, which is as low as this site's scale goes for a reason. Only 37.9% of flights arrive inside the 15-minute window, 39 points worse than the national rate of 77.3%. Late arrivals average a little over an hour. Treat any tight connection here as a coin flip. That rests on 214 flights. The strongest carrier on the route with a full sample, United Airlines, flew 2,666 at 67.2% on time.
United Airlines is the most reliable of the three carriers covered here at 67.2% on time across 2,666 flights.
Key figures
On time
37.9%
Arrivals under 15 minutes late, of 203 completed flights
Avg delay
75 min
Across delayed arrivals only, not all flights
Cancelled
5.14%
National rate is 1.89%
Whole route
59.5%
Every carrier on SAN to SFO, 6,763 flights
These figures cover 214 flights between September 2025 and August 2026. Beyond the headline rate, 27.6% 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 SAN to SFO
Frontier flew 214 of the 6,763 flights on SAN to SFO, about 3% of it. Its 37.9% on time is 22 points worse than the route as a whole, which runs 59.5%. Ranked by on-time rate it is last of five carriers on the route, where the range runs from United at 67.2% to Frontier at 37.9%. One 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 67.2% of the time; Southwest Airlines manages 52.4%. Sample sizes sit next to every figure, because a two-point gap across 2,070 flights means less than a ten-point one.
| Airline | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| United Airlines | 2,666 | 67.2% | 57 min | 0.56% | C+ |
| SkyWest Airlines | 1,482 | 59.8% | 64 min | 1.96% | D |
| Alaska Airlinesthin sample | 331 | 53.1% | 52 min | 1.51% | F |
| Southwest Airlines | 2,070 | 52.4% | 61 min | 1.30% | F |
| Frontier Airlines (this page)thin sample | 214 | 37.9% | 75 min | 5.14% | F− |
The spread between United and Southwest is 15 points, wide enough that it should decide the booking. On a hundred trips that is 15 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 61 points, against 15 points between the best and worst carrier.
- 5am–8am—
- 8am–11am27 flights—
- 11am–2pm38 flights84.2%
- 2pm–5pm5 flights—
- 5pm–8pm113 flights22.9%
- 8pm–5am31 flights—
Scale runs 15% to 90%. Rows with fewer than 30 flights show a dash.
The 5pm–8pm window is where this operation falls apart: 22.9% on time, against 84.2% for the 11am–2pm 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 113 flights scheduled in it.
Across the year
Frontier on SAN to SFO through the year
- Jul–Sep 202510 flights—
- Oct–Dec 202565 flights71.4%
- Jan–Mar 20269 flights—
- Apr–Jun 202668 flights18.0%
- Jul–Sep 202662 flights16.7%
Scale runs 10% 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 37.9% on time across 214 flights.
Frontier on SAN to SFO did not run the same all year. Its best quarter was Oct–Dec 2025 at 71.4% on time and its weakest Jul–Sep 2026 at 16.7%, a swing of 55 points on roughly 71 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, Saturday is the strongest day at 68.8% on time and Friday the weakest at 20.0%, a spread of 49 points.
Arrival by arrival
How late Frontier on SAN to SFO runs when it is late
The 126 late arrivals split 27 under half an hour, 43 between 30 and 60 minutes, and 56 an hour or more.
- 15+ min early41 flights20.2%
- Within 15 min36 flights17.7%
- 15–29 min late27 flights13.3%
- 30–59 min late43 flights21.2%
- 1–2 hours late44 flights21.7%
- 2+ hours late12 flights5.9%
Scale runs 0% to 100%.
Share of 203 completed flights by arrival against schedule.
Time lost at the gate mostly stays lost. Of 134 departures that left 15 minutes late or more, only 12 made it up before arrival. Only 4 left on time and still arrived late.
The worst days
Worst days for Frontier on SAN to SFO
The latest arrival of the period was on 2 January 2026, 13 hours 43 minutes behind schedule; most of its delay minutes were filed as carrier-caused (crew, maintenance, fuelling, baggage). The five worst days are spread across January, December, October and May, with no single month standing out.
| Date | Arrived late by | Largest filed cause |
|---|---|---|
| 2 January 2026 | 13 hours 43 minutes | Carrier |
| 5 December 2025 | 12 hours 49 minutes | Carrier |
| 11 October 2025 | 3 hours 11 minutes | Late-arriving aircraft |
| 28 May 2026 | 2 hours 50 minutes | National Airspace System |
| 24 December 2025 | 2 hours 43 minutes | Late-arriving aircraft |
Delay causes
Why Frontier runs late on this route
National Airspace System accounts for 58% of the 9,383 delay minutes carriers reported here, and the remaining four split what is left.
- 58%National Airspace System
- 22%Late-arriving aircraft
- 20%Carrier
58% 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 5,435 minutes out of 9,383, against a national NAS share of 21%. The split is drawn from 9,383 reported delay minutes.
Cancellations run at 5.14%, against 1.89% nationally. That is about one flight in twenty cancelled outright. A cancelled flight is invisible in every on-time figure on this page, so the punctuality numbers above describe only the flights that actually operated.
Connections and stage length
What a delay here costs
27.6% 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 447 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 11am–2pm window matters as much as it does.
The return leg is a different operation and performs like one: it runs 48.3% on time across 214 flights, 10 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 10 points of difference.
One caution: this is a thin sample. 214 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 SAN to SFO
Put together: the delay figures matter less here than the 5.14% cancellation rate. A late arrival costs you a little over an hour; a cancelled flight costs you the day. Book the 11am–2pm departure so there is still a schedule behind you if it goes wrong, and treat a same-day connection as optimistic. 203 completed flights over 12 months sit behind that.
Related
Where to go next
- SAN to SFO, every carrier
- Frontier on SFO to SAN, the return leg
- United Airlines on SAN to SFO67.2%
- SkyWest Airlines on SAN to SFO59.8%
- Alaska Airlines on SAN to SFO53.1%
- Southwest Airlines on SAN to SFO52.4%
- Frontier Airlines network-wide record
- San Diego International (SAN) delay statistics
- San Francisco International (SFO) delay statistics
- The US routes with the most cancellations
- Same route, different airline: where the carrier you pick matters most
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.