Carrier route record
F9SAN→SFO
Frontier Airlines · San Diego to San Francisco
- Flights
- 196
- Period
- July 2025 to June 2026
- Share of route
- 3%
- Carriers
- 5
Historical statistics for July 2025 to June 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 47.0% of flights arrive inside the 15-minute window, 31 points worse than the national rate of 77.6%. Late arrivals average an hour and a half. Treat any tight connection here as a coin flip. That rests on 196 flights. The strongest carrier on the route with a full sample, United Airlines, flew 2,598 at 70.6% on time.
United Airlines is the most reliable of the three carriers covered here at 70.6% on time across 2,598 flights.
Key figures
On time
47.0%
Arrivals under 15 minutes late, of 181 completed flights
Avg delay
83 min
Across delayed arrivals only, not all flights
Cancelled
7.65%
National rate is 1.81%
Whole route
65.0%
Every carrier on SAN to SFO, 6,583 flights
These figures cover 196 flights between July 2025 and June 2026. Beyond the headline rate, 25.4% 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 SAN to SFO
Frontier flew 196 of the 6,583 flights on SAN to SFO, about 3% of it. Its 47.0% on time is 18 points worse than the route as a whole, which runs 65.0%. Ranked by on-time rate it is last of five carriers on the route, where the range runs from United at 70.6% to Frontier at 47.0%. 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 70.6% of the time; Southwest Airlines manages 58.4%. Sample sizes sit next to every figure, because a two-point gap across 1,935 flights means less than a ten-point one.
| Airline | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| United Airlines | 2,598 | 70.6% | 60 min | 0.65% | C+ |
| SkyWest Airlines | 1,551 | 68.0% | 62 min | 1.74% | C |
| Southwest Airlines | 1,935 | 58.4% | 61 min | 1.09% | D |
| Alaska Airlinesthin sample | 303 | 54.0% | 55 min | 0.99% | F+ |
| Frontier Airlines (this page)thin sample | 196 | 47.0% | 83 min | 7.65% | F− |
The spread between United and Southwest is 12 points, wide enough that it should decide the booking. On a hundred trips that is 12 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 51 points, against 12 points between the best and worst carrier. Each bar is the on-time rate for flights scheduled inside that window.
- 5am–8am—
- 8am–11am20 flights—
- 11am–2pm38 flights84.2%
- 2pm–5pm5 flights—
- 5pm–8pm100 flights33.7%
- 8pm–5am33 flights50.0%
Scale runs 25% to 90%. Rows with fewer than 30 flights show a dash.
The 5pm–8pm window is where this operation falls apart: 33.7% 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 100 flights scheduled in it.
Across the year
Frontier on SAN to SFO through the year
- Jul–Sep 202554 flights54.2%
- Oct–Dec 202565 flights71.4%
- Jan–Mar 20269 flights—
- Apr–Jun 202668 flights18.0%
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 47.0% on time across 196 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 Apr–Jun 2026 at 18.0%, a swing of 53 points on roughly 65 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, Monday is the strongest day at 54.5% on time and Friday the weakest at 28.6%. 26 points is a smaller lever than departure hour, but it is free.
Delay causes
Why Frontier runs late on this route
Carriers report a reason for every delay minute they cause, in five DOT categories. The split below is by minutes, not by number of flights, so a handful of very long weather delays weighs as much as many short ones. It covers 8,005 reported delay minutes.
- 42%National Airspace System
- 32%Late-arriving aircraft
- 26%Carrier
42% 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 3,356 minutes out of 8,005, against a national NAS share of 21%. The split is drawn from 8,005 reported delay minutes.
Cancellations run at 7.65%, against 1.81% nationally. That is roughly one flight in twelve 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
For anyone connecting, the number to weigh is not the on-time rate but the tail behind it. 25.4% 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 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 53.7% on time across 196 flights, 7 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 7 points of difference.
One caution: this is a thin sample. 196 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 7.65% cancellation rate. A late arrival costs you an hour and a half; 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. 181 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 SFO70.6%
- SkyWest Airlines on SAN to SFO68.0%
- Southwest Airlines on SAN to SFO58.4%
- Alaska Airlines on SAN to SFO54.0%
- 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, July 2025 to June 2026. Last updated 15 September 2026; recomputed monthly. How this data is collected.