Carrier route record
OOSJC→SEA
SkyWest Airlines · San Jose to Seattle
- Flights
- 1,627
- 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 SJC to SEA earns an A+. Close to nine flights in ten arrive inside the 15-minute window the DOT uses to define an on-time arrival, which puts it 11 points better than the national rate of 77.3%. When something does go wrong the average delay runs about an hour. That rests on 1,627 flights. The strongest carrier on the route with a full sample, Alaska Airlines, flew 1,884 at 80.7% on time.
Set against the rest of the country, SkyWest's SJC to SEA record is 11 points better than the US average of 77.3%. That gap is worth roughly 114 fewer late arrivals for every thousand flights.
Key figures
On time
88.7%
Arrivals under 15 minutes late, of 1,623 completed flights
Avg delay
63 min
Across delayed arrivals only, not all flights
Cancelled
0.18%
National rate is 1.89%
Whole route
82.7%
Every carrier on SJC to SEA, 4,422 flights
These figures cover 1,627 flights between September 2025 and August 2026. The median arrival is 14 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 SJC to SEA
SkyWest flew 1,627 of the 4,422 flights on SJC to SEA, about 37% of it. Its 88.7% on time is 6 points better than the route as a whole, which runs 82.7%. Ranked by on-time rate it is number four of six carriers on the route, where the range runs from Delta at 100.0% to Southwest at 75.6%. Three of those carriers flew fewer than 365 flights here, so treat their positions as rough.
The two carriers here are closely matched: 5 points separate the best from the worst. At that spread, schedule and price are better tie-breakers than reliability. Sample sizes are shown so you can see which rows are worth weighing.
| Airline | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| Delta Air Linesthin sample | 4 | 100.0% | — | 0.00% | A+ |
| American Airlinesthin sample | 2 | 100.0% | — | 0.00% | A+ |
| United Airlinesthin sample | 1 | 100.0% | — | 0.00% | A+ |
| SkyWest Airlines (this page) | 1,627 | 88.7% | 63 min | 0.18% | A+ |
| Alaska Airlines | 1,884 | 80.7% | 51 min | 1.27% | B |
| Southwest Airlines | 904 | 75.6% | 46 min | 0.00% | B+ |
No carrier stands out. Alaska tops the table at 80.7%, 5 points clear of the bottom, which is inside the range this kind of sample moves year to year.
Flight by flight
SkyWest flight numbers on SJC to SEA
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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 11 points, against 5 points between the best and worst carrier.
- 5am–8am365 flights95.1%
- 8am–11am—
- 11am–2pm373 flights91.4%
- 2pm–5pm422 flights83.8%
- 5pm–8pm350 flights84.0%
- 8pm–5am117 flights92.3%
Scale runs 75% to 100%. Rows with fewer than 30 flights show a dash.
Book the early departure. Flights leaving between 5am–8am arrive on time 95.1% of the time, against 83.8% for the afternoon window. That is 11 points of difference for no extra money, and it comes from the same aircraft having had no earlier flight to fall behind on. The 2pm–5pm window is the busiest, with 422 flights scheduled in it.
Across the year
SkyWest on SJC to SEA through the year
December is the weak month at 81.8% on time, against 93.3% in April. Winter delays cluster: a single storm system can account for most of a month's shortfall, so an average December hides both very good weeks and genuinely unflyable days. July was the busiest month here, with 155 flights.
Across the week, Saturday is the strongest day at 94.1% on time and Monday the weakest at 86.2%, a spread of 8 points.
Arrival by arrival
How late SkyWest on SJC to SEA runs when it is late
SkyWest on SJC to SEA often beats the schedule: 789 of 1,623 completed flights, 49%, arrived 15 minutes or more early. The 183 late arrivals split 74 under half an hour, 55 between 30 and 60 minutes, and 54 an hour or more.
- 15+ min early789 flights48.6%
- Within 15 min651 flights40.1%
- 15–29 min late74 flights4.6%
- 30–59 min late55 flights3.4%
- 1–2 hours late28 flights1.7%
- 2+ hours late26 flights1.6%
Scale runs 0% to 100%.
Share of 1,623 completed flights by arrival against schedule.
34 of 163 late departures made up the time and arrived on time, 21% of them. 54 flights left on time and still arrived late.
The worst days
Worst days for SkyWest on SJC to SEA
The latest arrival of the period was on 24 November 2025, 11 hours 31 minutes behind schedule; most of its delay minutes were filed as carrier-caused (crew, maintenance, fuelling, baggage). The same cause led on four of the five worst days.
| Date | Arrived late by | Largest filed cause |
|---|---|---|
| 24 November 2025 | 11 hours 31 minutes | Carrier |
| 1 March 2026 | 7 hours 11 minutes | Carrier |
| 18 November 2025 | 5 hours 49 minutes | Carrier |
| 29 July 2026 | 5 hours 41 minutes | Carrier |
| 22 December 2025 | 4 hours | Late-arriving aircraft |
Delay causes
Why SkyWest runs late on this route
Carrier accounts for 67% of the 12,000 delay minutes carriers reported here, and the remaining four split what is left.
- 67%Carrier
- 19%Extreme weather
- 12%National Airspace System
- 2%Late-arriving aircraft
- 0%Security
Extreme weather accounts for 19% 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 3.1 times the usual weather exposure. The split is drawn from 11,561 reported delay minutes.
The largest share of delay minutes, 67%, falls under carrier control: crew scheduling, maintenance, fuelling, baggage. It accounts for 7,694 of the 12,000 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 3.3% 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 85.7% on time across 1,626 flights, 3 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 3 points of difference.
The sample behind these figures is 1,627 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 SJC to SEA
Put together: take the 5am–8am departure, avoid December if the dates are flexible, and if two carriers are within a few dollars of each other, Alaska is the one with the record behind it. None of that guarantees an on-time arrival; it moves the odds by 11 points, which is the most any booking decision can do. 1,623 completed flights over 12 months sit behind that.
Related
Where to go next
- SJC to SEA, every carrier
- SkyWest on SEA to SJC, the return leg
- Alaska Airlines on SJC to SEA80.7%
- Southwest Airlines on SJC to SEA75.6%
- SkyWest Airlines network-wide record
- Norman Y. Mineta San Jose International (SJC) delay statistics
- Seattle-Tacoma International (SEA) 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.