Carrier route record
OOSEA→SJC
SkyWest Airlines · Seattle to San Jose
- Flights
- 1,626
- Period
- September 2025 to August 2026
- Share of route
- 37%
- Carriers
- 6
Historical statistics for September 2025 to August 2026, not live status. For today’s flights, check with SkyWest Airlines.
SkyWest on SEA to SJC earns an A+. More than four flights in five arrive inside the 15-minute window the DOT uses to define an on-time arrival, which puts it 8 points better than the national rate of 77.3%. When something does go wrong the average delay runs about an hour. That rests on 1,626 flights. The strongest carrier on the route with a full sample, Alaska Airlines, flew 1,887 at 79.8% on time.
Set against the rest of the country, SkyWest's SEA to SJC record is 8 points better than the US average of 77.3%. That gap is worth roughly 84 fewer late arrivals for every thousand flights.
Key figures
On time
85.7%
Arrivals under 15 minutes late, of 1,623 completed flights
Avg delay
59 min
Across delayed arrivals only, not all flights
Cancelled
0.18%
National rate is 1.89%
Whole route
80.1%
Every carrier on SEA to SJC, 4,425 flights
These figures cover 1,626 flights between September 2025 and August 2026. The median arrival is 7 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
SkyWest against every carrier on SEA to SJC
SkyWest flew 1,626 of the 4,425 flights on SEA to SJC, about 37% of it. Its 85.7% on time is 6 points better than the route as a whole, which runs 80.1%. Ranked by on-time rate it is number four of six carriers on the route, where the range runs from United at 100.0% to Southwest at 70.5%. Three of those carriers flew fewer than 365 flights here, so treat their positions as rough.
The choice of carrier is not cosmetic here. Alaska Airlines arrives on time 79.8% of the time; Southwest Airlines manages 70.5%. Sample sizes sit next to every figure, because a two-point gap across 903 flights means less than a ten-point one.
| Airline | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| United Airlinesthin sample | 1 | 100.0% | — | 0.00% | A+ |
| Delta Air Linesthin sample | 4 | 100.0% | — | 0.00% | A+ |
| American Airlinesthin sample | 4 | 100.0% | — | 0.00% | A+ |
| SkyWest Airlines (this page) | 1,626 | 85.7% | 59 min | 0.18% | A+ |
| Alaska Airlines | 1,887 | 79.8% | 44 min | 1.06% | B |
| Southwest Airlines | 903 | 70.5% | 46 min | 0.22% | C+ |
Alaska leads Southwest by 9 points. Real, but small enough that a better departure time on the weaker carrier can outweigh it.
Flight by flight
SkyWest flight numbers on SEA to SJC
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Departure window
When SkyWest 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 1,626 flights.
- 5am–8am—
- 8am–11am438 flights90.0%
- 11am–2pm348 flights86.5%
- 2pm–5pm348 flights83.9%
- 5pm–8pm161 flights80.1%
- 8pm–5am331 flights83.9%
Scale runs 70% to 95%. Rows with fewer than 30 flights show a dash.
Book the morning departure. Flights leaving between 8am–11am arrive on time 90.0% of the time, against 80.1% for the evening window. That is 10 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 438 flights scheduled in it.
Across the year
SkyWest on SEA to SJC through the year
July is the worst month at 76.8% on time, 17 points below April, the best at 93.3%. 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 155 flights.
Across the week, Tuesday is the strongest day at 89.2% on time and Thursday the weakest at 83.2%, a spread of 6 points.
Arrival by arrival
How late SkyWest on SEA to SJC runs when it is late
SkyWest on SEA to SJC often beats the schedule: 483 of 1,623 completed flights, 30%, arrived 15 minutes or more early. The 232 late arrivals split 91 under half an hour, 77 between 30 and 60 minutes, and 64 an hour or more.
- 15+ min early483 flights29.8%
- Within 15 min908 flights55.9%
- 15–29 min late91 flights5.6%
- 30–59 min late77 flights4.7%
- 1–2 hours late40 flights2.5%
- 2+ hours late24 flights1.5%
Scale runs 0% to 100%.
Share of 1,623 completed flights by arrival against schedule.
37 of 204 late departures made up the time and arrived on time, 18% of them. 65 flights left on time and still arrived late.
The worst days
Worst days for SkyWest on SEA to SJC
The latest arrival of the period was on 10 August 2026, 11 hours 42 minutes behind schedule; most of its delay minutes were filed as carrier-caused (crew, maintenance, fuelling, baggage). On three of the five worst days the largest share was filed as extreme weather.
| Date | Arrived late by | Largest filed cause |
|---|---|---|
| 10 August 2026 | 11 hours 42 minutes | Carrier |
| 21 November 2025 | 9 hours 48 minutes | Extreme weather |
| 31 December 2025 | 4 hours 27 minutes | Extreme weather |
| 24 October 2025 | 4 hours 10 minutes | Carrier |
| 19 January 2026 | 3 hours 47 minutes | Extreme weather |
Delay causes
Why SkyWest runs late on this route
Carrier accounts for 58% of the 14,000 delay minutes carriers reported here, and the remaining four split what is left.
- 58%Carrier
- 28%Extreme weather
- 14%National Airspace System
- 0%Security
Extreme weather accounts for 28% of delay minutes, well above the single-digit share typical across the system. Weather delays are lumpy: they arrive as whole bad days rather than as a steady drag, so the monthly strip above is the more useful view of the risk. The national share is 6%, so this operation carries roughly 4.6 times the usual weather exposure. The split is drawn from 13,695 reported delay minutes.
The largest share of delay minutes, 58%, falls under carrier control: crew scheduling, maintenance, fuelling, baggage. It accounts for 7,997 of the 14,000 delay minutes reported here.
Cancellations are rare at 0.18%, 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 costs
Badly late arrivals are rare here: only 3.9% 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.
The 696 miles between these two airports put this in the middle of the US network, around two and a half to three hours of block time. That is enough cruise to absorb a ten-minute late pushback and not enough to absorb thirty.
The return leg is a different operation and performs like one: it runs 88.7% on time across 1,627 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 1,626 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 SEA to SJC
Put together: the calendar is the biggest lever here, not the carrier or the hour. April runs 93.3% on time and July 76.8%, a swing of 17 points. If the dates move at all, move them out of July before you think about anything else. 1,623 completed flights over 12 months sit behind that.
Related
Where to go next
- SEA to SJC, every carrier
- SkyWest on SJC to SEA, the return leg
- Alaska Airlines on SEA to SJC79.8%
- Southwest Airlines on SEA to SJC70.5%
- SkyWest Airlines network-wide record
- Seattle-Tacoma International (SEA) delay statistics
- Norman Y. Mineta San Jose International (SJC) delay statistics
- The best time of day to fly, according to 7.05 million flight records
- Worst months to fly in the US, ranked by the data
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.