AS476 SeattleSEA BostonBOS
AS476 by Alaska Airlines flies from Seattle (SEA) to Boston (BOS).
scheduled from SEA
The route today
live boardsWeather lens
Delay & cancellation outlook for this flight
Early read, sample still buildingConditions at SEA and BOS are near their clear-air norm right now, so this reflects the route's recent baseline rather than a weather penalty. For this route and airline, under conditions like today's, over the last 90 days. This route's tracked sample is still thin — treat these as an early read, not a precise forecast.
Pro Flight Search tracking, 90 days · the weather × delay correlation study → · live weather risk by airport →
When it flies
scheduled departuresEach mark is a scheduled departure at its origin-local time. Today is highlighted.
Other Seattle to Boston flights today
same route · Alaska AirlinesIf AS476 is cancelled, these are the other Alaska Airlines nonstop flights from Seattle to Boston on the same day, with scheduled departure times in SEA local time. Most flights posting a delay still operate — rebooking usually only beats a very large posted delay. Every airline on this route →
How AS476 actually runs
Pro Flight Search has tracked every published board update for AS476 across the SEA and BOS boards: schedule changes, gate pushes and actual clocks. Combined risk score: 23.2/100. Based on airport operations, weather, and cached board history at SEA and BOS.
The verdict above is that record speaking, so it reflects how AS476 operates rather than what the timetable promises. Numbers refresh as new flights operate.
Planning around AS476? Will a delayed flight be cancelled? · Do planes make up time in the air? · How we measure
Journalists, bloggers, and researchers may cite this page with attribution and a link to Pro Flight Search.
Pro Flight Search — AS476 Seattle to Boston on-time performance, measured from the SEA and BOS airport boards.
https://proflightsearch.com/flight/AS476
.