Flights Boston → Seattle — September 16, 2026

One way · Economy · 1 adult · price per person

The cheapest itinerary observed for Wednesday, September 16, 2026 on the Boston–Seattle route: 3 stops itinerary (4 flights) via Washington Dulles (IAD) and Calgary (YYC) and Denver International (DEN), from Boston Logan (BOS) to Seattle-Tacoma (SEA), first flight United Airlines UA1734, departs 5:45 AM, arrives 11:57 AM the next day, total travel time 33h 12m including layovers, flight time 11h 59m (layovers excluded), $273 per person. Fare as listed by Aviasales: carry-on bag not included (personal item only), checked bag not included, changes not allowed, non-refundable. Price found in an Aviasales search on September 9, 2026 and read by AirSource on September 10, 2026, 20:47 UTC: it is not guaranteed and is confirmed on Aviasales at booking time. The cheapest direct flight observed: JetBlue B6397, from Boston Logan (BOS) to Seattle-Tacoma (SEA), departs 7:20 PM, arrives 10:37 PM, direct, 6h 17m, $293 per person. Fare as listed by Aviasales: carry-on bag included, checked bag not included, changes not allowed, non-refundable.