Route reliability record
SAN→OAK
San Diego to Oakland
- Flights
- 3,195
- Period
- July 2025 to June 2026
- Distance
- 446 mi
- Carriers
- 3
This route sits in the middle of the pack with a C. Close to three flights in four arrive on time by the DOT's definition, 3 points worse than the national rate of 77.6%. The late ones land about 50 minutes behind schedule. That rests on 3,195 flights, with a median arrival 4 minutes early.
The US average over the same twelve months is 77.6%, so there is little to separate this route from the country as a whole. The variation that matters here is internal: which carrier, and what time of day.
Key figures
On time
74.5%
Arrivals under 15 minutes late, of 3,159 completed flights
Avg delay
50 min
Across delayed arrivals only, not all flights
Cancelled
1.10%
National rate is 1.81%
Best carrier
Southwest
74.5% on time across 2,940 flights
These figures cover 3,195 flights between July 2025 and June 2026. The median arrival is 4 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.
Carrier by carrier
Which airline is most reliable on SAN to OAK
Only one carrier clears this site's 365-flight floor here, so there is no comparison to draw. The table below is the full picture.
| Airline | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| Spirit Airlinesthin sample | 55 | 83.6% | 57 min | 0.00% | B+ |
| Southwest Airlines | 2,940 | 74.5% | 50 min | 1.09% | C |
| SkyWest Airlinesthin sample | 200 | 72.6% | 54 min | 1.50% | C |
Departure window
The best time of day to leave
Departure time matters more here than the choice of carrier. The gap between the best and worst window is 44 points, against half a point between the best and worst carrier. Each bar is the on-time rate for flights scheduled inside that window.
- 5am–8am349 flights97.7%
- 8am–11am662 flights88.7%
- 11am–2pm566 flights76.9%
- 2pm–5pm676 flights66.9%
- 5pm–8pm539 flights64.4%
- 8pm–5am403 flights53.9%
Scale runs 45% to 100%. Rows with fewer than 30 flights show a dash.
The 8pm–5am window is where this operation falls apart: 53.9% on time, against 97.7% for the 5am–8am 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 2pm–5pm window is the busiest, with 676 flights scheduled in it.
Across the year
When delays peak on this route
This route's year swings by 18 points from best month to worst, which is wide. An annual average tells you very little about the week you are actually flying, so read the strip rather than the headline if your dates are fixed.
June is the worst month at 65.4% on time, 18 points below January, the best at 83.6%. Summer afternoon convection and peak-season schedules land on the same weeks every year, so this is a pattern you can book around rather than a run of bad luck. May was the busiest month here, with 336 flights.
Across the week, Tuesday is the strongest day at 84.1% on time and Friday the weakest at 67.6%. 17 points is a smaller lever than departure hour, but it is free.
Delay causes
Why this route gets delayed
One category carries most of the weight here. Late-arriving aircraft accounts for 71% of the 40,000 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.
- 71%Late-arriving aircraft
- 23%Carrier
- 5%National Airspace System
- 0%Security
- 0%Extreme weather
71% of delay minutes trace back to a late-arriving aircraft, meaning the plane was already behind before it got here. That is a cascade, and cascades start small and grow through the day. Across 40,000 reported delay minutes here, that single category outweighs weather by 71 to one. It is the strongest argument for booking the first departure of the morning, when the aircraft has been sitting at the gate overnight with nothing to inherit. The split is drawn from 40,226 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 97.7% on time here.
Cancellations sit at 1.10% against a national 1.81%, which is ordinary. Diversions add another 0.03%.
Connections and stage length
What a delay here actually costs
6.8% of arrivals land an hour or more late, close to the national 8.1%. That is the figure that decides a connection, and it says a 60 to 75 minute layover is reasonable here while anything under 45 minutes is a bet. Most delays on this route are the about 50 minutes kind, which a normal layover absorbs.
At 446 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 66.9% on time across 3,201 flights, 8 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 8 points of difference.
The sample behind these figures is 3,195 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 this route
Put together: the calendar is the biggest lever here, not the carrier or the hour. January runs 83.6% on time and June 65.4%, a swing of 18 points. If the dates move at all, move them out of June before you think about anything else. 3,159 completed flights over 12 months sit behind that.
Common questions
SAN to OAK questions
How often is SAN to OAK delayed?
About one flight in four arrive at least 15 minutes late, which is the Department of Transportation's definition of a delayed arrival. That works out to 25.5% of the 3,195 flights in this analysis, against 22.4% nationally. Delayed flights are late by about 50 minutes on average.
How reliable is SAN to OAK compared with the rest of the country?
74.5% of flights arrive on time here against a national 77.6%, a difference of 3 points against it. That is worth a C on this site's grading scale.
What time of day has the fewest delays on SAN to OAK?
The 5am–8am departure window is the strongest at 97.7% on time. The 8pm–5am window is the weakest at 53.9%, 44 points behind. Later departures inherit delays from earlier flights the same aircraft has already flown, which is why the curve slopes the way it does.
How bad are June delays on SAN to OAK?
June is the weakest month at 65.4% on time, compared with 83.6% in January. Across the year that is 18 points between the best and worst months. Moving flexible dates out of that month is one of the few things that reliably helps.
Related
Where to go next
- OAK to SAN — the return legseparate record
- San Diego International (SAN) delay statistics
- Oakland International (OAK) delay statistics
- Spirit Airlines on-time record83.6%
- Southwest Airlines on-time record74.5%
- SkyWest Airlines on-time record72.6%
- Why the first flight of the morning is statistically safest
- The best time of day to fly, according to 7.04 million flight records
Direction matters. SAN to OAK and OAK to SAN are scored separately because they are separate operations, with different departure banks and different aircraft. Compare the return leg.
Source: US DOT Bureau of Transportation Statistics, on-time performance data, July 2025 to June 2026. Updated monthly. How this data is collected.