Seoul to San Francisco (ICN–SFO) — Airlines, Schedules & Connections

South Korean passport holders enter the United States under the Visa Waiver Program (VWP) for up to 90 days for tourism or business. You must obtain an approved ESTA (Electronic System for Travel Authorization) at esta.cbp.dhs.gov before travel. The ESTA costs $21, is processed within 72 hours (often minutes), and is valid for 2 years or until your passport expires, whichever comes first. Passport must be a biometric e-passport.

At US immigration, you clear CBP (Customs and Border Protection) where an officer reviews your ESTA, asks about your trip purpose, takes fingerprints and a photo, and determines your allowed stay (up to 90 days). Have your return ticket, hotel booking, and a general idea of your itinerary ready to answer questions. The 90-day VWP stay cannot be extended, and overstaying voids your ESTA and future VWP eligibility. For stays beyond 90 days or work purposes, apply for a visa at the US Embassy in Seoul.

Direct flights from Seoul Incheon to multiple US cities run 10 to 14 hours: Los Angeles (LAX) 11 hours, San Francisco (SFO) 11 hours 30 minutes, New York JFK 14 hours, Seattle (SEA) 10 hours, Dallas (DFW) 13 hours, and Atlanta (ATL) 14 hours. Korean Air, Asiana, Delta, United, and American all operate transpacific routes. The US uses the US dollar. No mandatory vaccinations. Global Entry ($100, valid 5 years) includes ESTA and provides expedited entry through automated kiosks at major US airports, a strong investment for frequent visitors.

AREX (Airport Railroad Express) runs two services from Seoul Station: the Direct Train (43 min, ₩11,000, reserved seats) and the All-Stop train (66 min, ₩4,550, unreserved). Both trains serve T1 first, then T2; confirm which terminal your airline uses before boarding.Limousine buses depart from major Seoul neighborhoods and hotels (₩16,000–18,000, 60–90 min depending on traffic). KAL and LIMOUSINE services are reliable. Taxis from central Seoul cost ₩65,000–80,000 and take 60–90 minutes. Deluxe (black) taxis are pricier but English-speaking drivers are more common.

BART from SFO station (free AirTrain from any terminal to the station) to downtown San Francisco takes 30–40 minutes ($10.45 to Embarcadero). Traffic on 101 can make taxis and ride-hails much slower during peak hours; BART skips all of that. BART also reaches Oakland, Berkeley, and Millbrae for Caltrain connections.Ride-hails from SFO use a dedicated garage pickup area; follow signs. Taxis are metered; downtown SF costs $40–60. Caltrain to the Peninsula (Mountain View, Palo Alto, San Jose) requires taking BART to Millbrae station for the transfer. Rental cars are at a consolidated facility accessible by AirTrain.

Coastal fog dominates the climate pattern. The thick marine layer ("Karl the Fog") rolls into SFO from the Pacific regularly in summer (June–September), causing significant low-visibility delays even on days that appear sunny inland. Morning fog burns off by afternoon most days, but persistent IFR conditions can last all day. This is the primary flight disruption risk at SFO.

Temperatures are mild year-round (10–20°C) with little seasonal variation. Winters bring rain (December–March) and occasional atmospheric river events that cause brief but intense flooding on the 101. Summers are cool. Pack a light jacket year-round. Wind off the bay affects small aircraft approach paths.