Route reliability record
SAN→SJC
San Diego to San Jose
- Flights
- 4,973
- Period
- September 2025 to August 2026
- Distance
- 417 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 77.3%. The late ones land about 50 minutes behind schedule. That rests on 4,973 SAN to SJC flights, of which SkyWest Airlines flew 1,112 at 80.7% on time.
Best time to fly SAN to SJC: a 5am–8am departure, ideally on a Wednesday. Flights in that window arrived on time 95.9% of the time and Wednesday flights 84.9%, against 74.5% for the route overall.
The US average over the same twelve months is 77.3%, 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 4,926 completed flights
Avg delay
50 min
Across delayed arrivals only, not all flights
Cancelled
0.88%
National rate is 1.89%
Best carrier
SkyWest
80.7% on time across 1,112 flights
These figures cover 4,973 flights between September 2025 and August 2026. The median arrival is 5 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
Which airline is most reliable on SAN to SJC
The choice of carrier is not cosmetic here. SkyWest Airlines arrives on time 80.7% of the time; Southwest Airlines manages 72.6%. Sample sizes sit next to every figure, because a two-point gap across 3,752 flights means less than a ten-point one.
| Airline | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| SkyWest Airlines | 1,112 | 80.7% | 56 min | 1.26% | B |
| Alaska Airlinesthin sample | 109 | 80.6% | 32 min | 0.92% | B+ |
| Southwest Airlines | 3,752 | 72.6% | 49 min | 0.77% | C+ |
SkyWest leads Southwest by 8 points. Real, but small enough that a better departure time on the weaker carrier can outweigh it.
Flight by flight
Flights on SAN to SJC
The flight numbers below flew this route at least 250 times in the period, busiest first. Each has its own record, with its schedule and delay causes.
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Best ways to make this trip
The most reliable ways to fly San Diego to San Jose
Every airline on this route and on the routes between nearby airports, ranked by how often a scheduled flight actually operated and arrived on time. 3 of the top 5 use a different airport at one end.
| Option | Airline | Success | On time | Cancelled | Best departure | Most punctual flight |
|---|---|---|---|---|---|---|
| 1. SAN → SJCSan Diego to San Jose | SkyWest Airlines | 79.7% | 80.7% | 1.26% | 5am–8am, Wed | OO 3359 08:01 |
| 2. SAN → SJCSan Diego to San Jose | Southwest Airlines | 72.0% | 72.6% | 0.77% | 5am–8am, Wed | — |
| 3. SAN → OAKSan Diego to Oakland | Southwest Airlines | 71.7% | 72.4% | 0.95% | 5am–8am, Sat | — |
| 4. SAN → SFOSan Diego to San Francisco | United Airlines | 66.8% | 67.2% | 0.56% | 5am–8am, Sat | UA 2117 16:00 |
| 5. SAN → SFOSan Diego to San Francisco | SkyWest Airlines | 58.6% | 59.8% | 1.96% | 8pm–5am, Sat | OO 3347 11:04 |
Success is the share of scheduled flights that operated and arrived less than 15 minutes late, so a cancelled flight counts against it. “(route)” means the best time comes from every carrier on the route rather than this airline alone.
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 33 points, against 8 points between the best and worst carrier.
- 5am–8am516 flights95.9%
- 8am–11am1,078 flights86.2%
- 11am–2pm820 flights72.3%
- 2pm–5pm835 flights62.8%
- 5pm–8pm1,068 flights67.2%
- 8pm–5am656 flights68.2%
Scale runs 55% to 100%.
Book the early departure. Flights leaving between 5am–8am arrive on time 95.9% of the time, against 62.8% for the afternoon window. That is 33 points of difference for no extra money, and it comes from the same aircraft having had no earlier flight to fall behind on. The 8am–11am window is the busiest, with 1,078 flights scheduled in it.
Explore
Filter SAN to SJC by airline, time, month and day
Pick a breakdown and a carrier. The dashed mark on each row is the same slice for every US flight.
On SAN to SJC, the best departure window is 5am–8am at 95.9% on time and the worst is 2pm–5pm at 62.8%, a wide gap of 33.1 points. All US flights leaving 5am–8am ran 89.3%.
- 5–8am95.9%
- 8–11am86.2%
- 11am–2pm72.3%
- 2–5pm62.8%
- 5–8pm67.2%
- 8pm–5am68.2%
best all US flightsScale 55% to 100%.
Across the year
When delays peak on this route
This route's year swings by 26 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.
August is the worst month at 60.8% on time, 26 points below January, the best at 86.7%. 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. July was the busiest month here, with 476 flights.
Across the week, Wednesday is the strongest day at 84.9% on time and Sunday the weakest at 66.8%, a spread of 18 points.
Delay causes
Why this route gets delayed
Late-arriving aircraft accounts for 69% of the 62,000 delay minutes carriers reported here, and the remaining four split what is left.
- 69%Late-arriving aircraft
- 22%Carrier
- 8%National Airspace System
- 2%Extreme weather
- 0%Security
69% of delay minutes trace back to a late-arriving aircraft, meaning the plane was already behind before it got here. Across 62,000 reported delay minutes here, that single category outweighs weather by 44 to one. The split is drawn from 62,184 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 95.9% on time here.
Cancellations are rare at 0.88%, below the national 1.89% and low enough to earn the plus on the grade. Roughly one flight in 100 is called off; the risk here is arriving late, not not arriving.
Connections and stage length
What a delay here actually costs
6.5% of arrivals land an hour or more late, close to the national 8.3%, so a 60 to 75 minute layover is reasonable here while anything under 45 minutes is a bet. Most delays on this route last about 50 minutes, which a normal layover absorbs.
At 417 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 68.3% on time across 5,004 flights, 6 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 6 points of difference.
The sample behind these figures is 4,973 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.
Work out the risk of missing a connection in SJC after this flight
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 86.7% on time and August 60.8%, a swing of 26 points. If the dates move at all, move them out of August before you think about anything else. 4,926 completed flights over 12 months sit behind that.
Common questions
SAN to SJC questions
How often is SAN to SJC delayed?
About one flight in four arrives 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 4,973 flights in this analysis, against 22.7% nationally. Delayed flights are late by about 50 minutes on average.
Which airline is most reliable on SAN to SJC?
SkyWest Airlines leads at 80.7% on time across 1,112 flights. Southwest Airlines is at the other end on 72.6%, a gap of 8 points. Sample size matters as much as the percentage: a rate built from a few hundred flights moves around far more than one built from ten thousand.
What time of day has the fewest delays on SAN to SJC?
The 5am–8am departure window is the strongest at 95.9% on time. The 2pm–5pm window is the weakest at 62.8%, 33 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 August delays on SAN to SJC?
August is the weakest month at 60.8% on time, compared with 86.7% in January. Across the year that is 26 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
- SJC to SAN — the return legseparate record
- San Diego International (SAN) delay statistics
- Norman Y. Mineta San Jose International (SJC) delay statistics
- SkyWest Airlines on SAN to SJC80.7%
- Alaska Airlines on SAN to SJC80.6%
- Southwest Airlines on SAN to SJC72.6%
- SAN to SFO, a related route59.5%
- LAX to SJC, a related route85.6%
- SAN to DEN, a related route78.4%
- SkyWest Airlines on-time record80.7%
- Alaska Airlines on-time record80.6%
- Southwest Airlines on-time record72.6%
- Why the first flight of the morning is statistically safest
- The best time of day to fly, according to 7.05 million flight records
Direction matters. SAN to SJC and SJC to SAN are scored separately because they are separate operations, with different departure banks and different aircraft. Compare the return leg.
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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.