Flight OddsAS304 BOS → SEA
Alaska Airlines · Boston, MA to Seattle, WA · 71 flights observed, 2025-07-01 to 2026-06-30 · 2,496 mi
AS304 covers more than one route in the data window — the stats below are for BOS → SEA, the one it has flown most recently. The others are linked under “Other routes”.
On-time arrival
77%
Median delay
+1 min
90th percentile
+40 min
Cancellation rate
0%
How often is AS304 on time?
Across 71 flights on BOS → SEA from 2025-07-01 to 2026-06-30, AS304 arrived within 15 minutes of schedule 77% of the time. The median arrival delay was +1 min, and the worst 10% of flights arrived +40 min or later. 0% of flights were cancelled.
Delay distribution
Arrival delay for completed flights (excludes cancellations and diversions).
| Arrival | Flights | Share |
|---|---|---|
| Early / on-time | 55 | 77% |
| 16-30 min | 7 | 10% |
| 31-60 min | 7 | 10% |
| 61-120 min | 2 | 3% |
| 2+ hrs | 0 | 0% |
Performance by month
| Month | Flights | On-time | Avg delay |
|---|---|---|---|
| 2025-07 | 31 | 74% | +9 min |
| 2025-08 | 19 | 95% | -10 min |
| 2026-06 | 21 | 67% | +7 min |
Performance by day of week
| Day | Flights | On-time |
|---|---|---|
| Mon | 10 | 100% |
| Tue | 11 | 73% |
| Wed | 10 | 80% |
| Thu | 10 | 40% |
| Fri | 10 | 90% |
| Sat | 10 | 90% |
| Sun | 10 | 70% |
Other routes
Related
Based on US Department of Transportation Bureau of Transportation Statistics on-time data. Loading live conditions and full charts…