Carrier route record
ASSAN→SFO
Alaska Airlines · San Diego to San Francisco
- Flights
- 303
- Period
- July 2025 to June 2026
- Share of route
- 5%
- Carriers
- 5
Historical statistics for July 2025 to June 2026, not live status. For today’s flights, check with Alaska Airlines.
Alaska on SAN to SFO earns an F+, which is as low as this site's scale goes for a reason. Only 54.0% of flights arrive inside the 15-minute window, 24 points worse than the national rate of 77.6%. Late arrivals average about 55 minutes. Treat any tight connection here as a coin flip. That rests on 303 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
54.0%
Arrivals under 15 minutes late, of 300 completed flights
Avg delay
55 min
Across delayed arrivals only, not all flights
Cancelled
0.99%
National rate is 1.81%
Whole route
65.0%
Every carrier on SAN to SFO, 6,583 flights
These figures cover 303 flights between July 2025 and June 2026. Beyond the headline rate, 17.0% 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
Alaska against every carrier on SAN to SFO
Alaska flew 303 of the 6,583 flights on SAN to SFO, about 5% of it. Its 54.0% on time is 11 points worse than the route as a whole, which runs 65.0%. Ranked by on-time rate it is number four 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 Airlines (this page)thin sample | 303 | 54.0% | 55 min | 0.99% | F+ |
| Frontier Airlinesthin 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 Alaska 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 303 flights.
The overnight block holds up unusually well at 54.0% on time across 268 flights. Red-eyes fly into empty airspace and empty gates, and they are the first rotation of the aircraft's day rather than the last. The 8pm–5am window is the busiest, with 268 flights scheduled in it.
Across the year
Alaska on SAN to SFO through the year
- Jul–Sep 202589 flights45.5%
- Oct–Dec 202573 flights68.5%
- Jan–Mar 202650 flights80.0%
- Apr–Jun 202691 flights36.0%
Scale runs 30% to 85%. 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 54.0% on time across 303 flights.
Alaska on SAN to SFO did not run the same all year. Its best quarter was Jan–Mar 2026 at 80.0% on time and its weakest Apr–Jun 2026 at 36.0%, a swing of 44 points on roughly 76 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 65.0% on time and Thursday the weakest at 45.5%. 20 points is a smaller lever than departure hour, but it is free.
Delay causes
Why Alaska runs late on this route
One category carries most of the weight here. National Airspace System accounts for 57% of the 7,549 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.
- 57%National Airspace System
- 33%Late-arriving aircraft
- 10%Carrier
- 1%Extreme weather
57% 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 4,266 minutes out of 7,549, against a national NAS share of 21%. The split is drawn from 7,549 reported delay minutes.
Cancellations sit at 0.99% 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. 17.0% 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 8pm–5am window matters as much as it does.
The return leg is a different operation and performs like one: it runs 88.8% on time across 304 flights, 35 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 35 points of difference.
One caution: this is a thin sample. 303 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 SAN to SFO
Put together: treat all of this as provisional. 303 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 54.0% headline is the most reliable number on the page; the hour and month splits below it are built on a few dozen flights each. 300 completed flights over 12 months sit behind that.
Related
Where to go next
- SAN to SFO, every carrier
- Alaska 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%
- Frontier Airlines on SAN to SFO47.0%
- Alaska Airlines network-wide record
- San Diego International (SAN) delay statistics
- San Francisco International (SFO) delay statistics
- Same route, different airline: where the carrier you pick matters most
- Why the first flight of the morning is statistically safest
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.