Carrier route record
ASSFO→SAN
Alaska Airlines · San Francisco to San Diego
- Flights
- 331
- Period
- September 2025 to August 2026
- Share of route
- 5%
- Carriers
- 5
Historical statistics for September 2025 to August 2026, not live status. For today’s flights, check with Alaska Airlines.
Alaska on SFO to SAN lands a B, 6 points better than the national rate of 77.3%. About one flight in six arrives 15 minutes late or worse, and those flights are late by about 45 minutes on average. That rests on 331 flights. The strongest carrier on the route with a full sample, United Airlines, flew 2,666 at 72.8% on time.
Set against the rest of the country, Alaska's SFO to SAN record is 6 points better than the US average of 77.3%. That gap is worth roughly 56 fewer late arrivals for every thousand flights.
Key figures
On time
82.9%
Arrivals under 15 minutes late, of 327 completed flights
Avg delay
44 min
Across delayed arrivals only, not all flights
Cancelled
1.21%
National rate is 1.89%
Whole route
62.2%
Every carrier on SFO to SAN, 6,723 flights
These figures cover 331 flights between September 2025 and August 2026. The median arrival is 3 minutes early, which is the part an average hides: most flights here are fine, and the on-time rate is decided by a tail of badly late ones. On-time means under 15 minutes late, the DOT's own threshold.
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Carrier by carrier
Alaska against every carrier on SFO to SAN
Alaska flew 331 of the 6,723 flights on SFO to SAN, about 5% of it. Its 82.9% on time is 21 points better than the route as a whole, which runs 62.2%. Ranked by on-time rate it is first of five carriers on the route, where the range runs from Alaska at 82.9% to Southwest at 47.9%. 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 72.8% of the time; Southwest Airlines manages 47.9%. 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 |
|---|---|---|---|---|---|
| Alaska Airlines (this page)thin sample | 331 | 82.9% | 44 min | 1.21% | B |
| United Airlines | 2,666 | 72.8% | 54 min | 0.34% | C+ |
| SkyWest Airlines | 1,442 | 60.1% | 59 min | 2.36% | D |
| Frontier Airlinesthin sample | 214 | 48.3% | 95 min | 4.21% | F− |
| Southwest Airlines | 2,070 | 47.9% | 62 min | 1.35% | F |
The spread between United and Southwest is 25 points, wide enough that it should decide the booking. On a hundred trips that is 25 more arrivals inside the on-time window.
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Departure window
When Alaska runs best on this route
Departure time matters more here than the choice of carrier. The gap between the best and worst window is 19 points, against 25 points between the best and worst carrier.
- 5am–8am213 flights90.6%
- 8am–11am105 flights71.6%
- 11am–2pm—
- 2pm–5pm—
- 5pm–8pm13 flights—
- 8pm–5am—
Scale runs 65% to 95%. Rows with fewer than 30 flights show a dash.
Book the early departure. Flights leaving between 5am–8am arrive on time 90.6% of the time, against 71.6% for the morning window. That is 19 points of difference for no extra money, and it comes from the same aircraft having had no earlier flight to fall behind on. The 5am–8am window is the busiest, with 213 flights scheduled in it.
Across the year
Alaska on SFO to SAN through the year
- Jul–Sep 202529 flights—
- Oct–Dec 202573 flights83.6%
- Jan–Mar 202650 flights96.0%
- Apr–Jun 202690 flights89.9%
- Jul–Sep 202689 flights68.6%
Scale runs 60% to 100%. 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 82.9% on time across 331 flights.
Alaska on SFO to SAN did not run the same all year. Its best quarter was Jan–Mar 2026 at 96.0% on time and its weakest Jul–Sep 2026 at 68.6%, a swing of 27 points on roughly 83 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 93.8% on time and Thursday the weakest at 72.9%, a spread of 21 points.
Arrival by arrival
How late Alaska on SFO to SAN runs when it is late
The 56 late arrivals split 25 under half an hour, 16 between 30 and 60 minutes, and 15 an hour or more.
- 15+ min early47 flights14.4%
- Within 15 min224 flights68.5%
- 15–29 min late25 flights7.6%
- 30–59 min late16 flights4.9%
- 1–2 hours late14 flights4.3%
- 2+ hours late1 flights0.3%
Scale runs 0% to 100%.
Share of 327 completed flights by arrival against schedule.
Time lost at the gate mostly stays lost. Of 36 departures that left 15 minutes late or more, only 3 made it up before arrival. In the other direction, 23 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 SAN.
The worst days
Worst days for Alaska on SFO to SAN
The latest arrival of the period was on 2 December 2025, 2 hours 28 minutes behind schedule; most of its delay minutes were filed as carrier-caused (crew, maintenance, fuelling, baggage). Three of the five worst days fell in August 2026.
| Date | Arrived late by | Largest filed cause |
|---|---|---|
| 2 December 2025 | 2 hours 28 minutes | Carrier |
| 24 August 2026 | 1 hour 59 minutes | Late-arriving aircraft |
| 1 December 2025 | 1 hour 48 minutes | Carrier |
| 27 August 2026 | 1 hour 40 minutes | Carrier |
| 3 August 2026 | 1 hour 37 minutes | Carrier |
Delay causes
Why Alaska runs late on this route
National Airspace System accounts for 53% of the 2,468 delay minutes carriers reported here, and the remaining four split what is left.
- 53%National Airspace System
- 31%Carrier
- 15%Late-arriving aircraft
- 1%Security
- 1%Extreme weather
53% 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 1,306 minutes out of 2,468, against a national NAS share of 21%. The split is drawn from 2,468 reported delay minutes.
Cancellations sit at 1.21% against a national 1.89%, which is ordinary. Diversions add another 0.00%.
Connections and stage length
What a delay here costs
Badly late arrivals are rare here: only 4.6% land an hour or more behind schedule, against 8.3% nationally. Connections built on this flight are about as safe as US domestic connections get, though a cancelled flight still ignores every layover you give it.
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 5am–8am window matters as much as it does.
The return leg is a different operation and performs like one: it runs 53.1% on time across 331 flights, 30 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 30 points of difference.
One caution: this is a thin sample. 331 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 Alaska on SFO to SAN
Put together: treat all of this as provisional. 331 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 82.9% headline is the most reliable number on the page; the hour and month splits below it are built on a few dozen flights each. 327 completed flights over 12 months sit behind that.
Related
Where to go next
- SFO to SAN, every carrier
- Alaska on SAN to SFO, the return leg
- United Airlines on SFO to SAN72.8%
- SkyWest Airlines on SFO to SAN60.1%
- Frontier Airlines on SFO to SAN48.3%
- Southwest Airlines on SFO to SAN47.9%
- Alaska Airlines network-wide record
- San Francisco International (SFO) delay statistics
- San Diego International (SAN) 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.