Route profile
SEA→SJC
Flight reliability, delays and best times to fly from Seattle to San Jose, 696 miles.
Right now
Aviation weather is not currently a factor.
Aviation weather is not currently a factor.
Route reliability
July 2023 – July 2026
Better than 84% of comparable major US routes (4,598 compared)
Calculated from 13,887 flights. How this is calculated
SEA → SJC arrives on time 81.3% of the time; the return trip, SJC → SEA, arrives on time 83.9% of the time, a 2.6-point gap between the two directions of the same city pair.
SEA → SJC spends 25.4 minutes on the ground on a 696-mile trip: 21.2 minutes from pushback to wheels-up at SEA and 4.3 minutes from touchdown to gate at SJC.
Source: US DOT Bureau of Transportation Statistics · Data covering July 2023 – July 2026
What stands out
This route holds up about the same all year, a steadier seasonal pattern than 93% of 3,357 comparable routes.
86.0% on time in its best month (April) against 75.6% in its worst (June).
Source: FlyerIntel analysis of US DOT BTS data · July 2023 – July 2026 · Ranked against every other route with the same kind of figure and at least 3,357 in the comparison.
Why SEA → SJC flights are cancelled
July 2023 – July 2026
SEA → SJC cancelled 101 of 13,887 scheduled flights — about 1 in every 137. The reason filed most often was the airline, 80.2% of the cancellations coded on this route — about 1 in every 171 scheduled flights.
Share of cancellations
Of 101 cancelled departures carrying a reason code.
What each reason means
Crew, maintenance, aircraft cleaning, baggage or fueling: what BTS counts as within the carrier’s own control.
81 cancellations, 80.2% of the total.
Conditions the carrier judged severe enough to stop the flight: a blizzard, a hurricane, a line of thunderstorms.
19 cancellations, 18.8% of the total.
Airport capacity, air traffic control flow programs, heavy traffic and ordinary bad weather. A system decision, not the airline’s.
1 cancellation, 1.0% of the total.
A terminal evacuation, a security breach, screening equipment failure, or screening queues over 29 minutes.
0 cancellations, 0.0% of the total.
Reason codes are the operating airline’s own filing with US DOT, not an independent finding of fault. Ordinary bad weather is filed under air traffic, so weather’s full share is larger than its bar.
101 coded cancellations were recorded on SEA → SJC; the section appears from 50.
When it goes wrong
July 2023 – July 2026
31 min late
against a median of 5 min early
Percentiles over 13,887 operations; cancelled and diverted flights are counted separately.
Will your connection be tight enough?
Layovers at SJC after arriving from SEA.
| Connection time | Chance of missing | Reads as |
|---|---|---|
| 30 min | 38% | Likely to miss |
| 45 min | 18% | High risk |
| 60 min | 10% | Some risk |
| 90 min | 4.3% | Low risk |
| 120 min | 2.2% | Low risk |
This is one leg of a connection. Gate changes and the next flight's own schedule matter too. And a connection can fail before delay is even the question — this route cancels 0.73% of the time and diverts 0.02% of the time, which a late arrival never shows up in.
Chance of missing is the share of 13,783 arrivals on this route that landed later than the connection time less 30 minutes to reach the next gate.
The worst tenth of arrivals on this route land at least 31 minutes late (90th-percentile gate arrival delay), over 13,887 operations.
Any other layover length: connection checker.
Best time to fly
SEA → SJC flights departing 5–9 AM arrived on time 90.7% of the time, against 64.9% for 9 PM–5 AM departures, a gap of 25.8 percentage points.
By departure window
By departure hour
- 12 AM to 5 AM: too few flights to score
- 6 AM: 93.8% on time from 605 flights
- 7 AM: 90.2% on time from 1,491 flights
- 8 AM: 89.4% on time from 850 flights
- 9 AM: 85.4% on time from 871 flights
- 10 AM: 86.4% on time from 421 flights
- 11 AM: 78.9% on time from 1,484 flights
- 12 PM: 75.0% on time from 712 flights
- 1 PM: 77.5% on time from 538 flights
- 2 PM: 82.0% on time from 664 flights
- 3 PM: 80.4% on time from 1,418 flights
- 4 PM: 80.9% on time from 611 flights
- 5 PM: 76.6% on time from 911 flights
- 6 PM: 73.5% on time from 544 flights
- 7 PM: 81.2% on time from 1,366 flights
- 8 PM: 72.0% on time from 1,162 flights
- 9 PM: 64.9% on time from 213 flights
- 10 PM to 11 PM: too few flights to score
Why SEA → SJC runs late
July 2023 – July 2026
crew, maintenance, boarding and fueling, all within the carrier’s control
the inbound aircraft was late, so this flight started late
airspace and airport capacity, including weather-driven flow control
weather severe enough to stop this flight specifically
screening or terminal security incidents
Share of the delay minutes US DOT attributed to each cause for SEA → SJC. Only delays of 15 minutes or more are attributed.
How this route holds up in bad weather
July 2023 – July 2026
Bad weather raises cancellations by a similar amount at both ends of SEA to SJC: 1.9 times the normal rate at SEA and 1.6 times at SJC. Cancelled in bad weather against normal hours: SEA 1.5% against 0.8%, SJC 1.0% against 0.6%. Flights that did leave SEA in bad weather arrived on time 75.4% of the time, against 79.3% in normal hours.
Bad weather and normal hours at the airports
Scheduled departures, July 2023 – July 2026| Departures from | SEA | SJC |
|---|---|---|
| Cancelled in bad weather | 1.5% | 1.0% |
| Cancelled in normal hours | 0.8% | 0.6% |
| Arrived on time, bad weather | 75.4% | 87.4% |
| Arrived on time, normal hours | 79.3% | 83.5% |
| Departures in bad weather | 43,416 | 4,322 |
Of the carriers on this route, Southwest Airlines (0.4% cancelled against 1.5% for the other carriers at SEA) cancelled the fewest departures from SEA in bad weather and Alaska Airlines (1.8% cancelled against 1.2% for the other carriers at SEA) the most.
This route’s airlines in bad weather at SEA
All departures from SEA| Airline | Bad-weather departures | Cancelled | Other carriers |
|---|---|---|---|
| Southwest Airlines | 2,229 | 0.4%below the others | 1.5% |
| SkyWest Airlines | 6,711 | 1.9%above the others | 1.5% |
| Alaska Airlines | 20,261 | 1.8%above the others | 1.2% |
These are airport figures, not route figures: every scheduled departure from SEA and SJC, to any destination, in hours the weather report called bad. The airline rows count each carrier’s departures from SEA on every route.
Weather source and limits. In full: SEA (airlines), SJC, What Weather Costs Each Airport, Who Cancels More When the Weather Turns, Airports That Change Places When Weather Turns.
Airlines on this route
Carriers with at least 200 flights, by the airline that operated each one.
| Carrier | Flights | On time | Cancelled | Median delay | Severe |
|---|---|---|---|---|---|
| Alaska Airlines | 5,867 | 79.6% | 1.43% | -4 min | 4.2% |
| SkyWest Airlines | 4,521 | 86.7% | 0.09% | -7 min | 3.8% |
| Southwest Airlines | 3,381 | 76.9% | 0.30% | -2 min | 5.3% |
Alaska Airlines flew 42.6% of the 13,769 flights listed. Alaska Airlines cancelled 1.43% of its flights here against 0.09% for SkyWest Airlines.
SkyWest Airlines arrived on time 9.8 percentage points more often than Southwest Airlines on this route.
Other ways to fly Seattle to San Francisco
Airport pairs in the same two city markets, as the DOT defines them.
| Route | Flights | On time | Cancelled | Median delay | Score |
|---|---|---|---|---|---|
| SEA→SFO Seattle to San Francisco | 20,772 | 68.7% | 1.02% | 0 min | 53 |
| SEA→SJC this route Seattle to San Jose | 13,887 | 81.3% | 0.73% | -5 min | 78 |
SEA → SJC is the most reliable pairing for this journey at 81.3% on time, against 68.7% for SEA → SFO.
Flights on this route
Flight numbers with at least 600 operations here and still on the schedule.
OO3736 (7:25 AM) arrived on time 88.0% of the time, 13.5 points more often than AS1310 (7:55 PM) at 74.5%.
Weekly and seasonal patterns
By day of week
Tuesday is historically the most reliable day and Friday the least, a gap of 7.8 percentage points.
By month
- Jan: 84.8%
- Feb: 82.8%
- Mar: 82.5%
- Apr: 86.0%
- May: 82.8%
- Jun: 75.6%
- Jul: 76.1%
- Aug: 78.7%
- Sep: 82.2%
- Oct: 83.9%
- Nov: 84.3%
- Dec: 80.1%
June is historically the weakest month and April the strongest, a spread of 10.4 percentage points.
Reliability over time
July 2023 – July 2026
- July 2023: 81.5% from 429 flights
- August 2023: 82.5% from 439 flights
- September 2023: 83.1% from 419 flights
- October 2023: 86.7% from 391 flights
- November 2023: 82.4% from 363 flights
- December 2023: 82.2% from 351 flights
- January 2024: 79.5% from 317 flights
- February 2024: 84.5% from 307 flights
- March 2024: 84.9% from 366 flights
- April 2024: 84.3% from 358 flights
- May 2024: 81.0% from 379 flights
- June 2024: 74.1% from 407 flights
- July 2024: 80.8% from 431 flights
- August 2024: 74.8% from 432 flights
- September 2024: 80.6% from 423 flights
- October 2024: 80.6% from 405 flights
- November 2024: 85.5% from 352 flights
- December 2024: 80.3% from 346 flights
- January 2025: 90.8% from 353 flights
- February 2025: 79.4% from 317 flights
- March 2025: 81.6% from 349 flights
- April 2025: 84.6% from 345 flights
- May 2025: 81.3% from 387 flights
- June 2025: 76.4% from 412 flights
- July 2025: 72.3% from 425 flights
- August 2025: 78.8% from 395 flights
- September 2025: 83.1% from 367 flights
- October 2025: 84.5% from 392 flights
- November 2025: 84.9% from 374 flights
- December 2025: 77.7% from 353 flights
- January 2026: 83.2% from 331 flights
- February 2026: 84.5% from 342 flights
- March 2026: 80.8% from 330 flights
- April 2026: 89.5% from 305 flights
- May 2026: 86.4% from 355 flights
- June 2026: 76.3% from 402 flights
- July 2026: 69.9% from 438 flights
Over the most recent 12 months (2025-08 to 2026-07), on-time arrivals averaged 81.3% against 80.4% in the 12 months before — broadly unchanged.
Data and methodology
Calculated by FlyerIntel from 13,887 SEA → SJC flight records from the US DOT Bureau of Transportation Statistics, covering July 2023 – July 2026. Late means 15 or more minutes past scheduled arrival; cancelled and diverted flights are left out of on-time rates.
Full methodology · Data sources · Report a problem
Related research: How Long a Layover Needs to Be · Two Airlines on One Route · Best Time of Day to Fly From Major US Airports
Analysis last recomputed