Flight OddsAS309 BOS → SEA
Alaska Airlines · Boston, MA to Seattle, WA · 36 flights observed, 2026-01-07 to 2026-02-11 · 2,496 mi
AS309 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
88%
Median delay
-11 min
90th percentile
+30 min
Cancellation rate
6%
How often is AS309 on time?
Across 36 flights on BOS → SEA from 2026-01-07 to 2026-02-11, AS309 arrived within 15 minutes of schedule 88% of the time. The median arrival delay was -11 min, and the worst 10% of flights arrived +30 min or later. 6% of flights were cancelled.
Delay distribution
Arrival delay for completed flights (excludes cancellations and diversions).
| Arrival | Flights | Share |
|---|---|---|
| Early / on-time | 30 | 88% |
| 16-30 min | 0 | 0% |
| 31-60 min | 4 | 12% |
| 61-120 min | 0 | 0% |
| 2+ hrs | 0 | 0% |
Performance by month
| Month | Flights | On-time | Avg delay |
|---|---|---|---|
| 2026-01 | 23 | 91% | -14 min |
| 2026-02 | 11 | 82% | +3 min |
Performance by day of week
| Day | Flights | On-time |
|---|---|---|
| Mon | 4 | 100% |
| Tue | 5 | 80% |
| Wed | 6 | 100% |
| Thu | 5 | 100% |
| Fri | 5 | 60% |
| Sat | 5 | 100% |
| Sun | 4 | 75% |
Other routes
Related
Based on US Department of Transportation Bureau of Transportation Statistics on-time data. Loading live conditions and full charts…