Cheap flights from Seattle to Keflavík (SEA–KEF)
SEASeattle–Tacoma International Airport
United States
United States
KEFKeflavik International Airport
Iceland
Iceland
Alaska Airlines and Icelandair fly Seattle to Keflavík (SEA–KEF) nonstop and back, a great-circle distance of 5,810 km (3,610 mi).
- From
- SEA
- Seattle
- To
- KEF
- Keflavík
- Nonstop
- Yes · 2 airlines
- Airlines
- AS · FI
- Cheapest fare found
- $510 one-way
- Distance
- 5,810 km (3,610 mi)
- Time difference
- Keflavík 7 hours ahead
- Most flights
- Icelandair
- Time in the air
- 6h 46m · 7h 25m back
- On time (Touchdown Index)
- 82.2%
- Flights a week
- AS ~1 · FI ~4
- Aircraft seen
- Boeing 737 Max 8 · Airbus A321neo
Network data imported from airport and airline sources:· How we verify
Seattle to Keflavík fares by month
Cheapest one-way fare found: $510 for December 2026 on Icelandair, nonstop. Nonstop from $510.
- Dec ’26$510
Cheapest one-way fares per month of departure in the Aviasales price cache, found . Fares change by the hour: the live fare is shown when you search.
Seattle to Keflavík: frequently asked questions
Fares: Aviasales price cache, 8 October 2026; tracked flights between 6 September and 3 October 2026, from public ADS-B data.
How much is a flight from Seattle–Tacoma (SEA) to Keflavík (KEF)?
From $510 one-way, the cheapest fare found for December 2026 on Icelandair, nonstop; nonstop from $510 (found 8 October 2026).
How long is the SEA–KEF flight?
6h 46m wheels-up to wheels-down, the median of 27 tracked flights; KEF–SEA took 7h 25m.
Which airlines fly SEA–KEF direct?
Alaska Airlines and Icelandair.
What is the time difference between Seattle and Keflavík?
Keflavík is 7 hours ahead of Seattle: a SEA departure at noon is 19:00 local time in KEF.
Is SEA–KEF usually on time?
82.2% of 45 SEA–KEF flights landed within 15 minutes of their usual time; 0% were over an hour late.
How many SEA–KEF flights a week?
Alaska Airlines 1 and Icelandair 4 each way.
What aircraft fly SEA–KEF?
Boeing 737 Max 8 and Airbus A321neo.
Keflavík to Seattle: the return flight (KEF–SEA)
All 2 airlines also fly KEF–SEA nonstop.
The return takes 7h 25m in the air (median of 11 tracked flights), 39 minutes longer than SEA–KEF.
Airlines flying SEA–KEF nonstop
| Airline | Usually takes off (SEA time) | Type | Alliance | Notes |
|---|---|---|---|---|
 Alaska Airlines AS | 18:56–19:19 | full-service | oneworld | Seasonal |
 Icelandair FI | 19:16–23:37 | full-service | — | — |
One-stop alternatives to flying SEA–KEF nonstop
One airline on both legs; check it's sold as one ticket.
- Via Minneapolis (MSP) with
Delta Air Lines: 6,970 km (4,330 mi) flown, 20% further than nonstop. - Via Toronto (YYZ) with
Air Canada: 7,480 km (4,650 mi) flown, 29% further than nonstop. - Via Chicago (ORD) with United Airlines: 7,490 km (4,650 mi) flown, 29% further than nonstop.
- Via Detroit (DTW) with Delta Air Lines: 7,580 km (4,710 mi) flown, 30% further than nonstop.
- Via Newark (EWR) with United Airlines: 8,030 km (4,990 mi) flown, 38% further than nonstop.
SEA–KEF route map
More from Seattle and Keflavík
Explore the airlines’ route maps
Departure
Seattle–Tacoma International Airport
Seattle–Tacoma (SEA), Seattle. In our data, 38 airlines fly nonstop from SEA to 136 destinations.
View SEA airport guide →Arrival
Keflavik International Airport
2 ways into Keflavík, fastest from 45 min:
- Flybus 45 min–1h · 3,899–4,999 ISK
- Strætó bus 55 1h–1h 20m · 2,400 ISK
Weather in Keflavík vs Seattle
Keflavík is cooler than Seattle in every month, by 5–12°C; the biggest gap is in August (14°C against 25°C). In October it averages 8°C in Keflavík and 16°C in Seattle.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Keflavík | 3° | 3° | 4° | 7° | 10° | 13° | 14° | 14° | 11° | 8° | 5° | 4° |
| Seattle | 9° | 10° | 12° | 15° | 19° | 22° | 25° | 25° | 22° | 16° | 11° | 8° |
Average daily highs. Climate normals from Keflavík and Climate of Seattle (Wikipedia, CC BY-SA), which cite the national weather services.
Onward from Keflavík
Places you can't fly to nonstop from SEA, but can from KEF — for a stopover or a second leg.
Related routes
Sources
- en.wikipedia.org — airlines and destinations, checked 2026-10-01
- en.wikipedia.org — airlines and destinations, checked 2026-10-01
- en.wikipedia.org — airlines and destinations table (passenger), checked 2026-10-01
- en.wikipedia.org — airlines and destinations table (passenger), checked 2026-10-01
- en.wikipedia.org — airlines and destinations table (passenger), checked 2026-10-01
- en.wikipedia.org — airlines and destinations table (passenger), checked 2026-10-01
- en.wikipedia.org — airlines and destinations table (passenger), checked 2026-10-01
- en.wikipedia.org — airlines and destinations table (passenger), checked 2026-10-01
- en.wikipedia.org — airlines and destinations table (passenger), checked 2026-10-01
- en.wikipedia.org — airlines and destinations table (passenger), checked 2026-10-01
- en.wikipedia.org — airlines and destinations table (passenger), checked 2026-10-01
- en.wikipedia.org — airlines and destinations table (passenger), checked 2026-10-01
- en.wikipedia.org — airlines and destinations table (passenger), checked 2026-10-01
- en.wikipedia.org — airlines and destinations table (passenger), checked 2026-10-01
- en.wikipedia.org — airlines and destinations table (passenger), checked 2026-10-01
- en.wikipedia.org — airlines and destinations table (passenger), checked 2026-10-01
- en.wikipedia.org — airlines and destinations table (passenger), checked 2026-10-01
- en.wikipedia.org — airlines and destinations table (passenger), checked 2026-10-01
- en.wikipedia.org — airlines and destinations table (passenger), checked 2026-10-01
- en.wikipedia.org — airlines and destinations table (passenger), checked 2026-10-01
- en.wikipedia.org — airlines and destinations table (passenger), checked 2026-10-01
- en.wikipedia.org — airlines and destinations table (passenger), checked 2026-10-01
- en.wikipedia.org — airlines and destinations table (passenger), checked 2026-10-01
- en.wikipedia.org — airlines and destinations table (passenger), checked 2026-10-01
- en.wikipedia.org — airlines and destinations table (passenger), checked 2026-10-01
- en.wikipedia.org — airlines and destinations table (passenger), checked 2026-10-01
- en.wikipedia.org — airlines and destinations table (passenger), checked 2026-10-01
- en.wikipedia.org — airlines and destinations table (passenger), checked 2026-10-01
- en.wikipedia.org — airlines and destinations table (passenger), checked 2026-10-01
- en.wikipedia.org — airlines and destinations table (passenger), checked 2026-10-01
- en.wikipedia.org — airlines and destinations table (passenger), checked 2026-10-01
- en.wikipedia.org — airlines and destinations table (passenger), checked 2026-10-01
- en.wikipedia.org — airlines and destinations table (passenger), checked 2026-10-01
- en.wikipedia.org — airlines and destinations table (passenger), checked 2026-10-01
- en.wikipedia.org — airlines and destinations table (passenger), checked 2026-10-01
- en.wikipedia.org — airlines and destinations table (passenger), checked 2026-10-01
- en.wikipedia.org — airlines and destinations table (passenger), checked 2026-10-01
- en.wikipedia.org — airlines and destinations table (passenger), checked 2026-10-01
- en.wikipedia.org — airlines and destinations table (passenger), checked 2026-10-01
- en.wikipedia.org — airlines and destinations table (passenger), checked 2026-10-01
- en.wikipedia.org — airlines and destinations table (passenger), checked 2026-10-01
- en.wikipedia.org — airlines and destinations table (passenger), checked 2026-10-01
- en.wikipedia.org — airlines and destinations table (passenger), checked 2026-10-01
- en.wikipedia.org — airlines and destinations table (passenger), checked 2026-10-01
- en.wikipedia.org — airlines and destinations table (passenger), checked 2026-10-01
- en.wikipedia.org — airlines and destinations table (passenger), checked 2026-10-01
- en.wikipedia.org — airlines and destinations table (passenger), checked 2026-10-01
- en.wikipedia.org — airlines and destinations table (passenger), checked 2026-10-01
- en.wikipedia.org — airlines and destinations table (passenger), checked 2026-10-01
- en.wikipedia.org — airlines and destinations table (passenger), checked 2026-10-01
- en.wikipedia.org — airlines and destinations table (passenger), checked 2026-10-01
- en.wikipedia.org — airlines and destinations table (passenger), checked 2026-10-01
- en.wikipedia.org — airlines and destinations table (passenger), checked 2026-10-01
- en.wikipedia.org — airlines and destinations table (passenger), checked 2026-10-01
- en.wikipedia.org — airlines and destinations table (passenger), checked 2026-10-01
- en.wikipedia.org — airlines and destinations table (passenger), checked 2026-10-01
- en.wikipedia.org — airlines and destinations table (passenger), checked 2026-10-01
- en.wikipedia.org — airlines and destinations table (passenger), checked 2026-10-01
- en.wikipedia.org — airlines and destinations table (passenger), checked 2026-10-01
- en.wikipedia.org — airlines and destinations table (passenger), checked 2026-10-01
- en.wikipedia.org — airlines and destinations table (passenger), checked 2026-10-01
- en.wikipedia.org — airlines and destinations table (passenger), checked 2026-10-01
- en.wikipedia.org — airlines and destinations table (passenger), checked 2026-10-01
- en.wikipedia.org — airlines and destinations table (passenger), checked 2026-10-01
- en.wikipedia.org — airlines and destinations table (passenger), checked 2026-10-01
- en.wikipedia.org — airlines and destinations table (passenger), checked 2026-10-01
- en.wikipedia.org — airlines and destinations table (passenger), checked 2026-10-01
- en.wikipedia.org — airlines and destinations table (passenger), checked 2026-10-01
- en.wikipedia.org — airlines and destinations table (passenger), checked 2026-10-01
- en.wikipedia.org — airlines and destinations table (passenger), checked 2026-10-01
- en.wikipedia.org — airlines and destinations table (passenger), checked 2026-10-01
- en.wikipedia.org — airlines and destinations table (passenger), checked 2026-10-01
- en.wikipedia.org — airlines and destinations table (passenger), checked 2026-10-01
- en.wikipedia.org — airlines and destinations table (passenger), checked 2026-10-01
- en.wikipedia.org — airlines and destinations table (passenger), checked 2026-10-01
- en.wikipedia.org — airlines and destinations table (passenger), checked 2026-10-01
- en.wikipedia.org — airlines and destinations table (passenger), checked 2026-10-01
- en.wikipedia.org — airlines and destinations table (passenger), checked 2026-10-01
Flight tracking: adsb.lol community ADS-B data (CC0), 6 September – 3 October 2026. Times are median wheels-up to wheels-down; add taxiing for gate-to-gate.
Report a change — seen something different at the airport or on the airline's site? We re-check and log corrections publicly.