Alaska Airlines now flies the longest nonstop route ever operated by a US carrier with a Boeing 737 — and it lands in Iceland. The seasonal daily service links Seattle-Tacoma (SEA) with Keflavík (KEF) aboard a 737 MAX 8, covering 3,611 miles in just under eight hours. The westbound return, AS355, is the longer leg at around 7 hours 55 minutes, and the route ranks as the second-longest scheduled 737 flight in the world, behind only GOL's Brasília–Orlando service.
The route launched on May 28 and was originally meant to end in mid-August. Demand told a different story: Alaska extended the season through September 7 and plans to start flights a week earlier for summer 2027. Load factors have been solid, with seats 77.2% full through June, and the US Department of Transportation counted 8,320 round-trip passengers on the route through that month. An August 12 total solar eclipse that crossed Iceland gave the first season an extra boost, as eclipse chasers from the Pacific Northwest snapped up the direct seats.
The clever bit is the codeshare. Through a bilateral agreement with Icelandair, passengers can connect at Keflavík to 35 European destinations — with the option of a stopover to soak up Iceland's glaciers, waterfalls and puffins before continuing on. For Seattle travellers, that means no layover slog through Chicago, New York or London to reach Europe.
The narrowbody experience has its own appeal. The MAX 8 is quiet, and its 'Sky Interior' LED lighting mimics sunrise and sunset to soften jet lag. Boarding and deplaning beat any 300-seat widebody, and cabin crews have fewer passengers to look after, which tends to make service snappier. As travel writer Ali Wunderman put it when describing Iceland's summer for the airline, the season isn't gentle — expect winds strong enough to bend car doors and fog that swallows entire fjords. But that wildness is exactly the draw, alongside the midnight sun.
For West Coast travellers eyeing Iceland or budget-friendly access to Europe, this is one of the most efficient options going: a flight that feels like a long domestic hop and drops you in one of the most striking countries on the planet.
