San Diego (SAN) to Seattle (SEA): On-Time Performance
Data through May 2026
San Diego (SAN) to Seattle (SEA) effectively runs on two schedules. In February 2026, 92% of arrivals were on time; in August 2025 that fell to 69% — a 23-point seasonal swing. Across the full period the route averages 80% on-time against a national 78%. Morning departures also hold up better than evening ones (84% vs 73%), which matters most in the rough months.
- On-time
- 80%
- arrived <15 min late
- Avg delay
- 14 min
- completed flights
- Cancelled
- 1.2%
- Flights/day
- 13
- last 12 months
- Duration
- 3h 7m
- scheduled
- Distance
- 1,050 mi
Best airline from SAN to SEA
3 airlines flew this route regularly between 2024-06 and 2026-05.
| Airline | On-time | Avg delay | Cancelled | Flights |
|---|---|---|---|---|
| Delta Air Linesmost reliable | 85% | 13 min | 0.6% | 3,396 |
| Alaska Airlines | 77% | 14 min | 1.6% | 5,680 |
| Southwest Airlines | 61% | 19 min | 0.0% | 88 |
Monthly on-time trend
Best time to fly from SAN to SEA
Aim for departures around 6 a.m. (92% on-time); avoid 6 p.m. departures (70%).
By day of week
| Day | On-time | Avg delay |
|---|---|---|
| Monday | 79% | 14 min |
| Tuesdaybest | 87% | 10 min |
| Wednesday | 83% | 9 min |
| Thursday | 79% | 15 min |
| Friday | 75% | 19 min |
| Saturday | 83% | 14 min |
| Sunday | 77% | 15 min |
What causes delays on this route
Share of total delay minutes by cause, as reported by carriers to the US DOT.
- Late-arriving aircraft47%
- Airline operations29%
- National airspace system20%
- Weather3%
Frequently asked questions
- How often are flights from SAN to SEA delayed?
- 20% of SAN–SEA flights arrived 15 or more minutes late (the US DOT definition of a delay) between 2024-06 and 2026-05. The average arrival delay across completed flights was 14 minutes.
- Which airline is most reliable from SAN to SEA?
- Delta Air Lines has the best on-time record on this route at 85%, based on 3,396 flights. 3 airlines flew SAN–SEA frequently enough to compare in this period.
- What is the best time of day to fly from SAN to SEA?
- Departures around 6 a.m. have the best record (92% on-time), while departures around 6 p.m. have the worst (70%). As on most US routes, delays accumulate through the day, so earlier flights are generally safer.
- How long is the flight from SAN to SEA?
- The scheduled SAN–SEA flight time averages 3h 7m over 1,050 miles. Actual arrival times vary — flights on this route land 15+ minutes late 20% of the time.
- How often are SAN to SEA flights cancelled?
- 1.2% of scheduled flights on this route were cancelled between 2024-06 and 2026-05, at or below the national rate of 1.6%.
- What is the worst month to fly from SAN to SEA?
- August 2025 was the roughest month in this dataset, with only 69% of arrivals on time. The best was February 2026 at 92%. If your dates are flexible, that 23-point gap is worth planning around.
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Based on 9,199 flights, 2024-06–2026-05. Source: US DOT Bureau of Transportation Statistics. Updated 2026-07-01.