Flight OddsAS521 SEA → SJC
Alaska Airlines · Seattle, WA to San Jose, CA · 184 flights observed, 2025-10-26 to 2026-06-09 · 696 mi
AS521 covers more than one route in the data window — the stats below are for SEA → SJC, the one it has flown most recently. The others are linked under “Other routes”.
On-time arrival
87%
Median delay
-7 min
90th percentile
+19 min
Cancellation rate
1%
How often is AS521 on time?
Across 184 flights on SEA → SJC from 2025-10-26 to 2026-06-09, AS521 arrived within 15 minutes of schedule 87% of the time. The median arrival delay was -7 min, and the worst 10% of flights arrived +19 min or later. 1% of flights were cancelled.
Delay distribution
Arrival delay for completed flights (excludes cancellations and diversions).
| Arrival | Flights | Share |
|---|---|---|
| Early / on-time | 159 | 87% |
| 16-30 min | 10 | 5% |
| 31-60 min | 5 | 3% |
| 61-120 min | 5 | 3% |
| 2+ hrs | 3 | 2% |
Performance by month
| Month | Flights | On-time | Avg delay |
|---|---|---|---|
| 2025-10 | 6 | 100% | -7 min |
| 2025-11 | 17 | 94% | -9 min |
| 2025-12 | 12 | 83% | +3 min |
| 2026-01 | 25 | 84% | -2 min |
| 2026-02 | 28 | 79% | +5 min |
| 2026-03 | 28 | 86% | +10 min |
| 2026-04 | 26 | 92% | -6 min |
| 2026-05 | 31 | 87% | +0 min |
| 2026-06 | 9 | 100% | -13 min |
Performance by day of week
| Day | Flights | On-time |
|---|---|---|
| Mon | 28 | 89% |
| Tue | 27 | 93% |
| Wed | 30 | 87% |
| Thu | 30 | 93% |
| Fri | 24 | 83% |
| Sat | 17 | 76% |
| Sun | 26 | 85% |
Other routes
Related
Based on US Department of Transportation Bureau of Transportation Statistics on-time data. Loading live conditions and full charts…