Flight OddsAS521 SJC → SEA
Alaska Airlines · San Jose, CA to Seattle, WA · 21 flights observed, 2026-06-10 to 2026-06-30 · 696 mi
AS521 covers more than one route in the data window — the stats below are for SJC → SEA, the one it has flown most recently. The others are linked under “Other routes”.
On-time arrival
75%
Median delay
+4 min
90th percentile
+30 min
Cancellation rate
5%
How often is AS521 on time?
Across 21 flights on SJC → SEA from 2026-06-10 to 2026-06-30, AS521 arrived within 15 minutes of schedule 75% of the time. The median arrival delay was +4 min, and the worst 10% of flights arrived +30 min or later. 5% of flights were cancelled.
Delay distribution
Arrival delay for completed flights (excludes cancellations and diversions).
| Arrival | Flights | Share |
|---|---|---|
| Early / on-time | 15 | 75% |
| 16-30 min | 3 | 15% |
| 31-60 min | 2 | 10% |
| 61-120 min | 0 | 0% |
| 2+ hrs | 0 | 0% |
Performance by month
| Month | Flights | On-time | Avg delay |
|---|---|---|---|
| 2026-06 | 20 | 75% | +6 min |
Performance by day of week
| Day | Flights | On-time |
|---|---|---|
| Mon | 2 | 50% |
| Tue | 3 | 100% |
| Wed | 3 | 100% |
| Thu | 3 | 67% |
| Fri | 3 | 67% |
| Sat | 3 | 67% |
| Sun | 3 | 67% |
Other routes
Related
Based on US Department of Transportation Bureau of Transportation Statistics on-time data. Loading live conditions and full charts…