Which city is represented by the code PSM?

The city represented by the code PSM is Portsmouth, New Hampshire. Airport city codes are typically based on the location of the airport, and PSM is the IATA airport code specifically assigned to Portsmouth International Airport at Pease. This code helps distinguish it from other airports and cities, ensuring clarity in travel and logistics within airline systems. The choice of codes often relies on identifying features of the city, such as its name's initials or recognizable abbreviations, making PSM representative of Portsmouth—a unique identifier that aids in travel planning and coordination.