About 1 in 4 AS 306 flights from Seattle arrived 15+ minutes late, diverted or cancelled over the past year (25%); 1.4% were cancelled. The typical flight landed 2 minutes early.
AS 306: SEA → BOS
Scheduled to leave Seattle at 8:23 a.m. local time. Over the past year it arrived on time 75% of the time (365 flights), in line with other AS flights on the route at that hour (74%). Last seen in the data Aug 31, 2026.
Month by month
By day of week
| Day | Flights | On time |
|---|---|---|
| Monday | 53 | 74% |
| Tuesday | 52 | 71% |
| Wednesday | 52 | 73% |
| Thursday | 52 | 71% |
| Friday | 52 | 73% |
| Saturday | 52 | 79% |
| Sunday | 52 | 81% |
Why it was late
All flights SEA → BOS · Connecting off AS 306? Check the risk
AS 306: BOS → SEA
Scheduled to leave Boston at 7:11 p.m. local time. Over the past year it arrived on time 57% of the time (129 flights), in line with other AS flights on the route at that hour (58%). Last seen in the data Aug 31, 2026.
Usually Alaska Airlines's last flight of the day from Boston to Seattle (100% of days). Alaska Airlines's last BOS–SEA flight was cancelled 2.5% of the time, against 0.9% for its earlier ones. If it's cancelled, the next Alaska Airlines flight is usually around 7:03 a.m. the next morning.
Month by month
By day of week
| Day | Flights | On time |
|---|---|---|
| Monday | 22 | 50% |
| Tuesday | 12 | — |
| Wednesday | 17 | — |
| Thursday | 20 | 35% |
| Friday | 20 | 55% |
| Saturday | 16 | — |
| Sunday | 22 | 45% |
Why it was late
All flights BOS → SEA · Connecting off AS 306? Check the risk
Questions
How often is AS 306 from SEA to BOS late?
Alaska Airlines 306 from Seattle, WA to Boston, MA arrived 15 or more minutes late, was diverted or was cancelled on 25% of 365 scheduled flights between September 2025 and August 2026. 1.4% were cancelled.
How often is AS 306 from BOS to SEA late?
Alaska Airlines 306 from Boston, MA to Seattle, WA arrived 15 or more minutes late, was diverted or was cancelled on 43% of 129 scheduled flights between September 2025 and August 2026. 1.6% were cancelled.
Flight numbers change. Figures cover flights with this airline, number and route only. "Likely range" is the 95% interval for the true on-time rate given the number of flights. This is history, not live status: check Alaska Airlines for today's flight. Method.