Los Angeles , often referred to by its initials L.A., officially the City of Los Angeles, is the most populous city in the U.S. state of California. With roughly 3.9 million residents within the city limits as of 2020, Los Angeles is the second-most populous city in the United States, behind only New York City; it is the commercial, financial and cultural center of the Southern California region. Los Angeles has a Mediterranean climate, an ethnically and culturally diverse population, in addition to a sprawling metropolitan area.