Carrier route record
OOSFO→SAN
SkyWest Airlines · San Francisco to San Diego
- Flights
- 1,515
- Period
- July 2025 to June 2026
- Share of route
- 23%
- Carriers
- 5
Historical statistics for July 2025 to June 2026, not live status. For today’s flights, check with SkyWest Airlines.
SkyWest on SFO to SAN draws a D. About one flight in three arrives at least 15 minutes late, and the typical late arrival is about an hour behind schedule. Build slack into anything you connect to. That rests on 1,515 flights. The strongest carrier on the route with a full sample, United Airlines, flew 2,598 at 76.2% on time.
The national on-time rate over the same period is 77.6%, so SkyWest on SFO to SAN runs 13 points behind the country as a whole. Across a thousand flights that is about 128 extra late arrivals.
Key figures
On time
64.8%
Arrivals under 15 minutes late, of 1,480 completed flights
Avg delay
57 min
Across delayed arrivals only, not all flights
Cancelled
2.05%
National rate is 1.81%
Whole route
66.6%
Every carrier on SFO to SAN, 6,548 flights
These figures cover 1,515 flights between July 2025 and June 2026. Beyond the headline rate, 12.1% 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
SkyWest against every carrier on SFO to SAN
SkyWest flew 1,515 of the 6,548 flights on SFO to SAN, about 23% of it. Its 64.8% on time is 2 points worse than the route as a whole, which runs 66.6%. Ranked by on-time rate it is number three of five carriers on the route, where the range runs from Alaska at 88.8% to Southwest at 52.8%. Two 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 76.2% of the time; Southwest Airlines manages 52.8%. 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 |
|---|---|---|---|---|---|
| Alaska Airlinesthin sample | 304 | 88.8% | 49 min | 0.33% | A+ |
| United Airlines | 2,598 | 76.2% | 55 min | 0.46% | B+ |
| SkyWest Airlines (this page) | 1,515 | 64.8% | 57 min | 2.05% | D |
| Frontier Airlinesthin sample | 196 | 53.7% | 76 min | 3.06% | F− |
| Southwest Airlines | 1,935 | 52.8% | 62 min | 1.24% | F |
The spread between United and Southwest is 23 points, wide enough that it should decide the booking. On a hundred trips that is 23 more arrivals inside the on-time window.
Departure window
When SkyWest runs best on this route
Departure time matters more here than the choice of carrier. The gap between the best and worst window is 36 points, against 23 points between the best and worst carrier. Each bar is the on-time rate for flights scheduled inside that window.
- 5am–8am153 flights90.6%
- 8am–11am341 flights62.9%
- 11am–2pm302 flights54.4%
- 2pm–5pm201 flights69.3%
- 5pm–8pm366 flights63.2%
- 8pm–5am152 flights61.5%
Scale runs 45% to 95%. Rows with fewer than 30 flights show a dash.
The weak window here is the middle of the day, not the evening: 11am–2pm runs 54.4% on time against 90.6% for 5am–8am. That shape usually means a departure bank rather than an accumulating delay, so the recovery later in the afternoon is real rather than noise. The 5pm–8pm window is the busiest, with 366 flights scheduled in it.
Across the year
SkyWest on SFO to SAN through the year
Delays peak in April, when the on-time rate falls to 36.6%. January is the strongest month at 83.7%. Moving a flexible trip across that boundary buys 47 points. September was the busiest month here, with 180 flights.
Across the week, Saturday is the strongest day at 78.2% on time and Friday the weakest at 54.6%. 24 points is a smaller lever than departure hour, but it is free.
Delay causes
Why SkyWest runs late on this route
One category carries most of the weight here. National Airspace System accounts for 52% of the 30,000 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.
- 52%National Airspace System
- 33%Late-arriving aircraft
- 15%Carrier
- 1%Extreme weather
52% 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 15,000 minutes out of 30,000, against a national NAS share of 21%. The split is drawn from 29,634 reported delay minutes.
The practical consequence: the 5am–8am departure is the one that starts clean. Its aircraft has no earlier leg to be late from, which is exactly why that window shows 90.6% on time here.
Cancellations sit at 2.05% against a national 1.81%, which is ordinary. Diversions add another 0.26%.
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. 12.1% 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 5am–8am window matters as much as it does.
The return leg is a different operation and performs like one: it runs 68.0% on time across 1,551 flights, 3 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 3 points of difference.
The sample behind these figures is 1,515 flights, enough that the headline rate is stable to within roughly a point. The hour-block and month splits divide that further, so read the thinner bars with more caution than the headline.
What to do with this
Booking SkyWest on SFO to SAN
Put together: the calendar is the biggest lever here, not the carrier or the hour. January runs 83.7% on time and April 36.6%, a swing of 47 points. If the dates move at all, move them out of April before you think about anything else. 1,480 completed flights over 12 months sit behind that.
Related
Where to go next
- SFO to SAN, every carrier
- SkyWest on SAN to SFO, the return leg
- Alaska Airlines on SFO to SAN88.8%
- United Airlines on SFO to SAN76.2%
- Frontier Airlines on SFO to SAN53.7%
- Southwest Airlines on SFO to SAN52.8%
- SkyWest Airlines network-wide record
- San Francisco International (SFO) delay statistics
- San Diego International (SAN) delay statistics
- Why the first flight of the morning is statistically safest
- 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.