Carrier route record
OOSJC→SEA
SkyWest Airlines · San Jose to Seattle
- Flights
- 1,563
- Period
- July 2025 to June 2026
- Share of route
- 36%
- Carriers
- 5
Historical statistics for July 2025 to June 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 12 points better than the national rate of 77.6%. When something does go wrong the average delay runs about an hour. That rests on 1,563 flights. The strongest carrier on the route with a full sample, Alaska Airlines, flew 1,874 at 82.0% on time.
Set against the rest of the country, SkyWest's SJC to SEA record is 12 points better than the US average of 77.6%. That gap is worth roughly 119 fewer late arrivals for every thousand flights.
Key figures
On time
89.5%
Arrivals under 15 minutes late, of 1,559 completed flights
Avg delay
66 min
Across delayed arrivals only, not all flights
Cancelled
0.19%
National rate is 1.81%
Whole route
83.3%
Every carrier on SJC to SEA, 4,368 flights
These figures cover 1,563 flights between July 2025 and June 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.
Carrier by carrier
SkyWest against every carrier on SJC to SEA
SkyWest flew 1,563 of the 4,368 flights on SJC to SEA, about 36% of it. Its 89.5% on time is 6 points better than the route as a whole, which runs 83.3%. Ranked by on-time rate it is number three of five carriers on the route, where the range runs from American at 100.0% to Southwest at 75.6%. Two 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 82.0% of the time; Southwest Airlines manages 75.6%. Sample sizes sit next to every figure, because a two-point gap across 928 flights means less than a ten-point one.
| Airline | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| American Airlinesthin sample | 2 | 100.0% | — | 0.00% | A+ |
| United Airlinesthin sample | 1 | 100.0% | — | 0.00% | A+ |
| SkyWest Airlines (this page) | 1,563 | 89.5% | 66 min | 0.19% | A+ |
| Alaska Airlines | 1,874 | 82.0% | 49 min | 1.65% | B |
| Southwest Airlines | 928 | 75.6% | 45 min | 0.00% | B+ |
Alaska leads Southwest by 6 points. Real, but small enough that a better departure time on the weaker carrier can outweigh it.
Flight by flight
SkyWest flight numbers on SJC to SEA
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 6 points between the best and worst carrier. Each bar is the on-time rate for flights scheduled inside that window.
- 5am–8am365 flights94.5%
- 8am–11am—
- 11am–2pm373 flights92.0%
- 2pm–5pm426 flights85.4%
- 5pm–8pm344 flights85.4%
- 8pm–5am55 flights96.4%
Scale runs 75% to 100%. Rows with fewer than 30 flights show a dash.
The 8pm–5am window is the strongest at 96.4% on time. The full set of windows spans 11 points.
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. May was the busiest month here, with 150 flights.
Across the week, Saturday is the strongest day at 93.5% on time and Monday the weakest at 87.2%. 6 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. Carrier accounts for 64% of the 11,000 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.
- 64%Carrier
- 19%Extreme weather
- 14%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 10,804 reported delay minutes.
The largest share of delay minutes, 64%, falls under carrier control: crew scheduling, maintenance, fuelling, baggage. Unlike weather, that is a management outcome, and it is the category where the gap between two carriers on the same schedule is genuinely earned. It accounts for 6,951 of the 11,000 delay minutes reported here.
Cancellations are rare at 0.19%, below the national 1.81% 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 3.0% land an hour or more behind schedule, against 8.1% 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. It is also long enough that the aircraft usually flies three or four legs a day rather than six, which slows how fast delay compounds.
The return leg runs 88.0% on time across 1,562 flights, within 2 points of this direction. The two legs are scored separately because they usually differ; on this city pair they happen not to.
The sample behind these figures is 1,563 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: avoid the 5pm–8pm departure. It runs 85.4% on time against 96.4% for the 8pm–5am slot, and that 11 points is the largest single thing you control here. Alaska Airlines is the strongest operator if the fares are close. 1,559 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 SEA82.0%
- 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 7.04 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, July 2025 to June 2026. Last updated 15 September 2026; recomputed monthly. How this data is collected.