What is the city code for San Francisco, California?

The city code for San Francisco, California, is SFO. This code is part of the International Air Transport Association (IATA) system, which assigns unique three-letter codes to airports around the world. SFO specifically corresponds to San Francisco International Airport, which serves as a major hub for domestic and international flights.

The other options represent codes for different locations. PDX is the code for Portland International Airport in Oregon. KDN is not a widely recognized airport code and does not correspond to any major airport. JNU is the code for Juneau International Airport in Alaska. Understanding city codes is essential for travel planning, ticket booking, and airport navigation. Thus, SFO is the correct representation for San Francisco.