Icelandair plays an important role between Europe and the US. In the 12 months to September 2025, the carrier transported 1.6 million round-trip passengers to/from the country. Traffic rose by 7% compared to the prior 12 months, which was more than double the rate of the whole Europe-US market.

Iceland’s flag carrier’s higher passenger volume was influenced by the start Nashville flights in April 2025 and the cessation of PLAY in September. The retirement of additional Boeing 757-200s did not help, but deliveries of more Airbus A321LR broadly balanced it.

Icelandair’s US Routes With The Lowest Load Factors

Credit: GCMap

Between October 2024 and September 2025, Cirium Diio data shows that the airline had 15 US passenger routes. Number 16, Keflavik to Miami, started in October; I was on the first flight. When passengers are considered, the US was by far the airline’s most-served country. Around 31% of its total passengers flew to/from the US.

Of course, without such a comprehensive US network, Icelandair’s European map would not be as substantial or as frequently served. That’s because booking data suggests around seven in ten passengers bound to/from the US connected to another flight in Keflavik.

Icelandair’s average load factor across all 15 routes was 81.2%. This information, along with all the figures mentioned in the opening two paragraphs and shown in the following table, is based on examining the latest data from the Department of Transportation. All articles that analyze such things, including my recent look at Aer Lingus’ performance, use it.

Keflavik To Detroit Had The Worst Result

Credit: Detroit Metropolitan Wayne County Airport

Icelandair arrived in Michigan in May 2023, more than four years after the now-defunct WOW Air pulled out. While Icelandair’s flights were initially only during the summer, as might be expected, the carrier operated for longer in 2024. This continued in 2025, albeit with only two round-trip services in January, none in February, and seven in March.

In contrast, Icelandair’s sole direct competitor, Delta, only operated during the summer, a period with the highest loads and fares. Despite its daily offering, its average load was 78.1%. That was 11 points higher than Icelandair’s 67.0% result with only three to five weekly flights. Still, Delta’s load was far below its Europe-wide average of 85.9%, with Icelandair’s exit helping to boost performance in the upcoming summer.

Icelandair ended its Detroit route on January 3, 2026. It covered 2,426 nautical miles (4,493 km) each way. In its less than three-year existence, the 160-seat Boeing 737 MAX 8—its lowest-capacity jet equipment—was used on nearly all the flights. An estimated 73% of passengers connected at Keflavik, particularly to London Heathrow, Stockholm Arlanda, Paris CDG, Oslo, and Dublin.

Related

Only 64% Full: Aer Lingus’ 10 Emptiest US Routes Revealed

Aer Lingus’ decision to increase frequencies and add more A330-300 flights on this route meant the load factor fell…

Pittsburgh’s Result Was Interesting

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Icelandair began flying to Pittsburgh in May 2024, five years after WOW Air pulled out. Flights continue to operate four times a week on the 737 MAX 8, with only a seasonal service available, which is sensible.

In 2024, the route operated between May and October, while flights existed between April and October last year. In the first year, 74.4% of seats were filled. However, between April and September 2025 (October data is unavailable), the US DOT shows it fell to just 69.2%—even though it was still a new route.

Of course, seat factor is only one measure and should not be considered in isolation. The airline would have received highly attractive incentives and may have other risk-sharing agreements, which must also be factored in. But there’s no denying it. On the face of it, 69.2% is very low. It’ll be good to see what happens to the route.