Boston, MA → Seattle, WA flight delays
BOS → SEA · all airlines · 254 flights · May 2026 · source: US BTS
This route is delayed
21%of the time, by +38 min on average when it does.
This is history, not a promise — your specific flight could well be on time.
On-time rate
79%
Delayed 3h+
0%
Cancelled
0.4%
Avg when late
+38m
Best & worst day to fly
Most on-time
Saturday
delayed 3%
Worst
Thursday
delayed 29%
Which airline is most punctual on BOS → SEA?
Alaskadelayed 21%
Deltadelayed 23%
Frequently asked
How often is the Boston, MA to Seattle, WA flight delayed?
About 21% of BOS → SEA flights arrive late (15+ minutes), by an average of 38 minutes when they do, based on 254 flights in May 2026.
Which airline is most punctual on BOS → SEA?
Alaska, delayed 21% of the time — the best of the 2 airlines flying this route.
What is the best day to fly BOS → SEA?
Saturday is the most on-time (delayed 3%), while Thursday is the worst (delayed 29%).
Airport overviews