How often are SEA to BOS flights on time?

Flights from Seattle (SEA) to Boston (BOS) arrive on time 87% of the time across 14,597 flights of official data.

Which airline is most reliable on the SEA to BOS route?

Delta Air Lines has the best on-time record on this route at 91% across 5,456 flights.

Route reliability

Flights from Seattle to Boston arrive on time 87% of the time across 14,597 flights. Here’s how each airline really performs.

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On-time rate

14,597 flights

On-time = arrived within 15 minutes of schedule, per BTS TranStats. Compare the reverse leg BOS → SEA.

How to Pick a Reliable Flight (Not Just the Cheapest)

A practical checklist for booking the flight that gets you there — not just the cheap one.

Nonstop vs. Connecting Flights: The Reliability Trade-off

A stop multiplies the ways a trip can break. When it's worth it — and how to de-risk it.

Do Morning Flights Really Have Fewer Delays?

Yes — and there's a clear reason. How delays snowball through the day.

Are Some Airlines Really More Reliable Than Others?

The reliability gap between airlines is real — here's what actually drives it.

Score real SEA–BOS flights on reliability, weather, and connection safety — not just price.