Best Time to Fly SAN to SEA: On-Time Stats by Hour & Airline
San Diego International → Seattle/Tacoma International
Data through July 2026 · Last updated October 18, 2026
Over the last 12 months, 81.0% of San Diego (SAN) to Seattle (SEA) flights arrived on time (4,593 scheduled flights). That is 3.4 points above the national average of 77.6%.
Among 3 airlines, Delta Air Lines led with 87.4% on time and Southwest Airlines was last with 58.8%.
Over 24 months, Tuesday was the most reliable day (87% on time) and June the worst month (74%).
The cancellation rate was 1.5% (US average 1.8%).
SAN to SEA on-time performance by airline
Last 12 months. Airlines with fewer than 30 completed flights are marked “limited data”.
| Airline | On time | Avg delay when late | Cancelled | Flights |
|---|---|---|---|---|
| Delta Air Lines | 87.4% | 75 min | 1.1% | 1,704 |
| Alaska Airlines | 78.3% | 62 min | 1.8% | 2,739 |
| Southwest Airlines | 58.8% | 49 min | 0.0% | 149 |
| SkyWest Airlines | Limited data | 1 | ||
80%+ good 70–79.9% fair <70% poor
Best time of day to fly SAN to SEA
On-time arrival % by scheduled departure hour (local time), 9,244 flights over 24 months.
Show the numbers
| Departure hour | On time | Cancelled | Flights |
|---|---|---|---|
| 6am–7am | 92.4% | 2.6% | 690 |
| 7am–8am | 85.0% | 0.9% | 1,177 |
| 8am–9am | 72.9% | 1.5% | 327 |
| 9am–10am | 80.1% | 3.1% | 327 |
| 10am–11am | 83.6% | 0.7% | 406 |
| 11am–12pm | 83.6% | 0.9% | 1,064 |
| 12pm–1pm | 75.0% | 0.9% | 339 |
| 1pm–2pm | 81.0% | 0.4% | 1,011 |
| 2pm–3pm | 81.8% | 0.5% | 389 |
| 3pm–4pm | 79.9% | 0.9% | 891 |
| 4pm–5pm | 75.0% | 0.8% | 489 |
| 5pm–6pm | 74.0% | 2.3% | 437 |
| 6pm–7pm | 69.4% | 1.1% | 572 |
| 7pm–8pm | 73.5% | 0.7% | 723 |
| 8pm–9pm | 75.3% | 3.1% | 385 |
| 9pm–10pm | Limited data | 16 | |
| 10pm–11pm | Limited data | 1 | |
Best day of the week
24 months, by day of departure.
Best month to fly
24 months, by calendar month.
Holiday travel on SAN to SEA
On-time arrivals during holiday periods compared with all other days, last 24 months.
| Period | On time | vs other days | Cancelled | Flights |
|---|---|---|---|---|
| Thanksgiving week (Tue before to Mon after) | 84.5% | +2.4 pts | 1.9% | 158 |
| Christmas & New Year (Dec 20 - Jan 3) | 71.6% | -10.5 pts | 2.6% | 344 |
| Summer peak (Jun 15 - Aug 15) | 72.7% | -9.5 pts | 2.1% | 1,799 |
| All other days | 82.1% | — | 0.9% | 6,943 |
Monthly on-time trend
On-time arrival % each month, with the 12-month US average for reference.
What causes delays on this route
Share of reported delay minutes, last 12 months (BTS cause categories).