Denver to Seoul (DEN–ICN) — Airlines, Schedules & Connections

US passport holders enter South Korea visa-free for up to 90 days under the K-ETA (Korea Electronic Travel Authorization) exemption. As of early 2026, the K-ETA requirement is waived for US citizens through December 2025 (check for extensions beyond this date). When the K-ETA is required, apply at k-eta.go.kr at least 72 hours before travel for KRW 10,000 (about $7). Passport must be valid for at least 6 months beyond the date of entry. At Incheon International Airport (ICN), immigration uses automated gates for repeat visitors or stamps your passport at the counter.

South Korea counts the 90 days from entry, not cumulatively within a period, so you can exit and re-enter for a fresh 90 days. Incheon Airport consistently ranks among the world's best: free showers, a Korean culture center, an ice skating rink, and transit hotels are all inside the terminals. The KTX high-speed train connects Seoul to Busan in 2 hours 15 minutes, Daejeon in 50 minutes, and Gwangju in 1 hour 40 minutes.

Direct flights from New York JFK to Incheon run about 14 hours on Korean Air, Asiana, and Delta. Los Angeles (LAX) to ICN runs about 12 hours 30 minutes. Direct service also operates from San Francisco, Seattle, Dallas, Chicago, Atlanta, and Honolulu. South Korea uses the Korean won (KRW), trading at roughly 1,380 KRW per $1. T-money cards work on Seoul's metro (9 lines), buses, taxis, and convenience stores. A single metro ride costs KRW 1,400 ($1). The AREX express train runs from Incheon Airport to Seoul Station in 43 minutes for KRW 9,500 ($6.90). Street food at Gwangjang Market or Myeongdong runs KRW 3,000 to KRW 8,000 ($2.20 to $5.80) per item. Korean BBQ meals cost KRW 15,000 to KRW 30,000 ($10.90 to $21.75) per person.

RTD A Line commuter rail runs from Denver Union Station to the airport (37 min, $10.50). Trains depart every 15 minutes during peak hours. The airport is 25 miles northeast of downtown; ride-shares cost $35–55 and take 30–45 minutes depending on I-70 traffic.Economy parking in lots 4–6 connects via free shuttle. Mountain shuttle services depart from Jeppesen Terminal's Ground Transportation level.

AREX Direct Train to Seoul Station (43 min, ₩11,000) is a reserved-seat express. The All-Stop train serves Hongik University, City Hall, and other inner-city stations (66 min, ₩4,550). T2 passengers board at a dedicated T2 stop before T1; don't exit early. City Check-in at Seoul Station allows bag drop and boarding pass printing before the train for select airlines.Limousine buses serve major hotel zones and neighborhoods (₩16,000–18,000). Taxis from ICN to central Seoul cost ₩65,000–90,000; use only official orange (general) or black (deluxe) cabs from the designated stands. KakaoTaxi (ride-hail) operates from the airport.

Humid continental climate. Winters are cold and dry (−8 to 2°C, December–February) with occasional snow and wind chill. ICN handles snow well, though heavy falls delay operations. Summer monsoon (Changma) runs late June through July with heavy continuous rain. Typhoons can affect operations August–September with short notice.

Spring brings Yellow Dust (hwangsa) from China. Fine particulate storms reduce visibility and occasionally disrupt flights in March–April. Autumn (October–November) is the best flying season: clear skies, low humidity, 8–18°C. Pack layers for spring and fall. Summer is hot and humid (25–32°C).